@article {354, title = {Phytophthora alni subsp. uniformis found in Alaska beneath thinleaf alders}, journal = {Plant Health Progress}, year = {2008}, abstract = {

Phytophthora alni Brasier \& S. A. Kirk 2004 is an emergent pathogen causing a lethal root and collar disease of alder species in Europe. The species has not been previously found in North America, although an isolate tentatively referred to as P. alni was reported in a survey of nurseries in Minnesota. The potential establishment and spread of this complex of pathogens is perceived to represent a threat to all species of Alnus in the western hemisphere.

}, doi = {doi:10.1094/PHP-2008-1212-02-BR}, url = {http://www.plantmanagementnetwork.org/php/elements/sum2.aspx?id=7094}, author = {G. C. Adams and M. Catal and L. Trummer and Hansen, E.M. and P. Reeser and J. J. Worrall} } @article {doi:10.2989/20702620.2012.717381, title = {Potential of Phytophthora pinifolia to spread via sawn green lumber: a preliminary investigation}, journal = {Southern Forests: a Journal of Forest Science}, volume = {74}, number = {4}, year = {2012}, pages = {211-216}, abstract = {

Phytophthora pinifolia causes the needle and shoot disease of Pinus radiata in Chile known as Da{\~n}o Foliar del Pino. Although P. pinifolia is primarily a needle pathogen, there are concerns that it might be spread to new environments via the export of contaminated timber. In order to determine whether P. pinifolia can enter or persist in green sawn lumber, its presence in lumber produced from trees exposed to the pathogen for at least four years was examined. Green lumber produced from the infected trees, and green wood samples artificially exposed to P. pinifolia inoculum, were analysed by making extensive isolations on Phytophthora selective media. In addition, PCR was conducted using species-specific primers developed for P. pinifolia. Results of the study showed that the green sawn lumber taken from trees infected by P. pinifolia, or green lumber exposed in infected pine plantations, displayed no evidence of the pathogen surviving in this material.

}, doi = {10.2989/20702620.2012.717381}, url = {http://www.tandfonline.com/doi/abs/10.2989/20702620.2012.717381}, author = {Ahumada, R. and Rotella, A. and Slippers, B. and Wingfield, M. J.} } @article {4261, title = {Phytophthora foot rot of black pepper in Brazil and Puerto Rico}, journal = {Phytopathology}, volume = {62}, year = {1972}, pages = {144-148}, doi = {10.1094/Phyto-62-144}, url = {http://www.apsnet.org/publications/phytopathology/backissues/Documents/1972Articles/Phyto62n01_144.PDF}, author = {Alconero, R and Albuquerque, F and Almeyda, N and Santiago, AG} } @article {4572, title = {Phytophthora cinnamomi A1: An ancient resident of New Guinea and Australia of Gondwanan origin?}, journal = {Forest Pathology}, year = {2017}, month = {Jan-02-2017}, pages = {e12342}, abstract = {

This article re-examines the hypothesis, first proposed by Shepherd (Search, 6(11-12), 1975, 484), that Phytophthora cinnamomi is an ancient organism in Australia and New Guinea. It further evaluates data that suggest the A1 mating type is Gondwanan in origin and may have been present in New Guinea for up to 10\ million years. It is postulated that there has been a mating type change in P.\ cinnamomi from A1 to A2 in relatively recent times as a result of genetic transformation of the A1 mating type.

}, issn = {1439-0329}, doi = {10.1111/efp.12342}, url = {http://doi.wiley.com/10.1111/efp.12342}, author = {Arentz, F.}, editor = {Woodward, S.} } @article {JPH:JPH1079, title = {PCR-based DNA Markers for identifying hybrids within Phytophthora alni}, journal = {Journal of Phytopathology}, volume = {154}, number = {3}, year = {2006}, pages = {168{\textendash}177}, publisher = {Blackwell Verlag GmbH}, abstract = {

Two pairs of oligonucleotide primers were designed for the polymerase chain reaction (PCR)-based detection and differential identification of naturally occurring interspecific hybrid types (subspecies) of Phytophthora alni, all of which cause collar rot of alder trees. Primer pairs were derived from randomly amplified polymorphic DNA (RAPD) fragments that were unique to various subspecies of this alder pathogen. The primer pair set, SAP1/SAP2 (SAP), was derived from a 0.93-kb RAPD fragment amplified from P. alni ssp. alni. The primer pair set, SWAP1/SWAP2 (SWAP), was derived from a 1.13-kb fragment amplified from P. alni ssp. uniformis. Patterns of SAP and SWAP amplification enabled distinction among the three subspecies. No PCR products were amplified from isolates of 31 other Phytophthora spp. examined, including P. cambivora and P. fragariae, the suspected progenitors of P. alni. The SAP and SWAP primer sets were able to detect a minimum of 10\ pg of DNA from pure cultures or DNA extracted from as few as 10 zoospores. Pathogen DNA could also be amplified directly from bark lesions of artificially inoculated and naturally infected common alders and from lesions developed on common cherry-laurel leaves used in baiting the pathogen from infested soil. Direct detection of pathogen DNA from alder tissue using SAP and SWAP primer sets should prove useful in developing measures for effective quarantine and management of P. alni.

}, keywords = {Alnus, oomycete, Phytophthora alni, polymerase chain reaction markers, species hybrids}, issn = {1439-0434}, doi = {10.1111/j.1439-0434.2006.01079.x}, url = {http://dx.doi.org/10.1111/j.1439-0434.2006.01079.x}, author = {Bakonyi, J. and Nagy, Z. {\'A}. and {\'E}rsek, T.} } @article {4042, title = {Phytophthora quercetorum sp. nov., a novel species isolated from eastern and north-central USA oak forest soils}, journal = {Mycological Research}, volume = {112}, year = {2008}, month = {08/2008}, pages = {906 - 916}, abstract = {

Isolates belonging to an undescribed Phytophthora species were frequently recovered during an oak forest soil survey of Phytophthora species in eastern and north-central USA in 2004. The species was isolated using an oak leaf baiting method from rhizosphere soil samples collected from Quercus rubra, Q. macrocarpa, and Q. phellos. This species is formally described as P. quercetorum. It is homothallic and has aplerotic oogonia and paragynous antheridia. It produces papillate sporangia (occasionally bipapillate) of ovoid-elongated shapes. Its temperature optimum for growth is ca 22.5\ {\textdegree}C with the upper limit of ca 32.5\ {\textdegree}C. P. quercetorum differs from the morphologically related P. quercina in producing distinct submerged colony-patterns, different growth-temperature requirements, and oogonial shapes and sizes. Phylogenetic analyses using seven nuclear loci supported P. quercetorum as a novel species within clade 4, closely related to P. arecae, P. palmivora, P. megakarya, and P. quercina.

}, issn = {09537562}, doi = {10.1016/j.mycres.2008.02.008}, url = {http://www.sciencedirect.com/science/article/pii/S0953756208000841}, author = {Yilmaz Balci and Balci, Selin and Jaime E. Blair and Sook-Young Park and Seogchan Kang and Macdonald, William L.} } @article {doi:10.1094/PDIS-91-6-0705, title = {Phytophthora spp. associated with forest soils in eastern and north-central U.S. oak ecosystems}, journal = {Plant Disease}, volume = {91}, number = {6}, year = {2007}, pages = {705-710}, doi = {10.1094/PDIS-91-6-0705}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-91-6-0705}, author = {Balci, Y. and Balci, S. and Eggers, J. and MacDonald, W. L. and Juzwik, J. and Long, R. P. and Gottschalk, K. W.} } @book {4254, title = {Phytophthora basal canker of red maple}, series = {Plant Pathology Circular}, volume = { No. 361}, year = {1993}, publisher = {Fla. Dept. Agric. \& Consumer Services. Division of Plant Industry}, organization = {Fla. Dept. Agric. \& Consumer Services. Division of Plant Industry}, address = {Gainseville, FL. }, url = {http://www.freshfromflorida.com/content/download/11368/144504/pp361.pdf}, author = {Barnard, E.L. and Mitchell, D.J.} } @article {4553, title = {Phytophthora gonapodyides Causes Decline and Death of English (Persian) Walnut ( Juglans regia) in Italy}, journal = {Plant Disease}, volume = {100}, year = {2016}, month = {Jan-12-2016}, pages = {2537 - 2537}, abstract = {

In late spring 2015, several commercially grown Persian walnut (Juglans regia L.) cv. Lara trees in northeastern Italy (Udine) exhibited extensive foliar wilt and canopy decline associated with collar and root rot. Sudden collapse was recorded in about 80\% of trees facing an irrigation canal. Symptomatic tissues excised from roots and collars of affected plants were surface disinfested for 1 min in a 1\% NaOCl solution, rinsed for 5 min in sterile distilled water, and placed onto P5ARPH selective medium. A Phytophthora-like organism was consistently isolated. Pure cultures, with a typical rosette pattern, were obtained by single-hyphal transfers onto potato dextrose agar (PDA). Mycelial disks of three isolates, AB260, AB261, and AB262, grown on carrot piece agar, were floated in petri plates with soil extract solution and incubated under continuous fluorescent light at room temperature. Within 48 to 72 h, sporangia were produced that were persistent, nonpapillate, tapered at the apex, and 40.0 to 102.8 {\texttimes} 22.8 to 45.7 {\textmu}m (average 56 {\texttimes} 33 {\textmu}m of 30 sporangia). Both internal and external proliferations were observed. Oospores and chlamydospores were absent. These morphological characteristics all corresponded to those reported for Phytophthora gonapodyides (Brasier et al. 1993; Erwin and Ribeiro 1996). Optimal growth for all three isolates was at 30{\textdegree}C (3.4 mm/day), with limited growth at 4{\textdegree}C (1.25 mm/day), and no growth at 35{\textdegree}C. The identity was confirmed by sequencing the internal transcribed spacer (ITS) using universal primers ITS4 and ITS6 (Cooke et al. 2000) and cytochrome c oxidase, subunit II (Cox II) (Martin and Tooley 2003). BLAST analysis of ITS 821-bp segment (GenBank accession nos. LN877760, LN901312, LN901313) showed 100\% identity with published P. gonapodyides sequences available in GenBank (i.e., HQ261570, AF541889, or AF541888), as well as with a Cox II 568-bp segment (LN877762, LN894191, LN894192) against AY129197. Greenhouse pathogenicity tests were conducted in controlled conditions. A total of six 1-year-old shoots cut from J. regia plants, about 2 cm in diameter, were used and three inoculation points each were made. Mycelial plugs (6 mm in diameter) cut from margins of actively growing 10-day-old cultures on PDA were inserted through the epidermis into phloem tissue. Controls were treated as described above except that sterile PDA plugs replaced the inoculum. Shoots were incubated in test tubes with sterile water in the dark at 24 {\textpm} 2{\textdegree}C. After 2 weeks, lesions were evident at all inoculation points, with an average length of 26 mm. Symptoms were similar to those caused by natural infection. P. gonapodyides was consistently reisolated from lesion margins. No colonies were isolated from control plants that remained symptomless. P. gonapodyides is ubiquitous in streams and ephemeral water pools, and is capable of saprophytic existence (Erwin and Ribeiro 1996). Although it is mainly known as a minor pathogen, there are reports indicating that some isolates can be highly virulent (Orlikowski et al. 2011) as in the present study where well developed 7-year-old walnut trees were killed by the pathogen. In the current study, P. gonapodyides aggressiveness was most likely sustained by the prolonged presence of flooding water at the root level, and a cool soil environment. To our knowledge, this is the first report of P. gonapodyides on Persian walnut in Italy or elsewhere.

}, issn = {0191-2917}, doi = {10.1094/PDIS-03-16-0394-PDN}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-03-16-0394-PDN}, author = {Belisario, A. and Luongo, L. and Vitale, S. and Galli, M. and Haegi, A.} } @article {4720, title = {Phytophthora spp. associated with Appalachian oak forests and waterways in Pennsylvania, with P. abietivora as a pathogen of five native woody plant species.}, journal = {Plant Disease}, year = {2021}, month = {11/2021}, abstract = {

To document the distribution of potentially harmful Phytophthora spp. within Pennsylvania (PA), the PA Department of Agriculture collected 89 plant, 137 soil, and 48 water samples at 64 forested sites from 2018 to 2020. In total, 231 Phytophthora strains were isolated using baiting assays and identified based on morphological characteristics and sequences of nuclear and mitochondrial loci. Twenty-one Phytophthora spp. in nine clades and one unidentified species were present. Phytophthora abietivora, a recently described clade 7a species, was recovered from diseased tissue of 10 native broadleaved plants and twice from soil from 12 locations. Phytophthora abietivora is most likely endemic to PA based on pathogenicity tests on six native plant species, intraspecific genetic diversity, wide distribution, and recoveries from Abies Mill. and Tsuga Carri{\`e}re plantations dating back to 1989. Cardinal temperatures and morphological traits are provided for this species. Other taxa, in decreasing order of frequency, include P. chlamydospora, P. plurivora, P. pini, P. cinnamomi, P. xcambivora, P. irrigata, P. gonapodyides, P. cactorum, P. pseudosyringae, P. hydropathica, P. stricta, P. xstagnum, P. caryae, P. intercalaris, Phytophthora {\textquoteleft}bitahaiensis{\textquoteright}, P. heveae, P. citrophthora, P. macilentosa, P. cryptogea, and P. riparia. Twelve species were associated with diseased plant tissues. This survey documented 53 new plant-Phytophthora associations and expanded the known distribution of some species.

}, issn = {0191-2917}, doi = {10.1094/PDIS-05-21-0976-RE}, url = {https://apsjournals.apsnet.org/doi/10.1094/PDIS-05-21-0976-RE}, author = {Bily, Devin and Nikolaeva, Ekaterina V. and Olson, Tracey and Kang, Seogchan} } @article {Blaha19941379, title = {Phytophthora isolates from coconut plantations in Indonesia and Ivory Coast: characterization and identification by morphology and isozyme analysis}, journal = {Mycological Research}, volume = {98}, number = {12}, year = {1994}, pages = {1379 - 1389}, abstract = {

Isolates of Phytophthora were obtained from coconut palms with bud rot and/or premature nut-fall disease in Indonesia (36 isolates) and Ivory Cost (15 isolates), and from coconut plantation soil in Indonesia (17 isolates). Their morphology and isozyme patterns for MDH and GPI were compared with those of seven known Phytophthora species. Isolates from Indonesia assigned to P. arecae or P. palmivora by morphology had identical isozyme patterns and could not be separated by cluster analysis. Isolates of P. palmivora had one single-banded, and three triple-banded GPI patterns, one of which was unique to isolates from coconut. Isolates from Ivory Coast were assigned by morphology and by a distinctive MDH isozyme pattern to P. katsurae. They showed some morphological similarities, and had an identical GPI isozyme pattern to reference cultures of P. heveae, previously reported as a pathogen on coconut. We conclude that P. palmivora is the main pathogen associated with bud rot and premature nut-fall in Indonesia, whereas P. katsurae is associated with premature nut-fall in Ivory Coast.

}, issn = {0953-7562}, doi = {DOI: 10.1016/S0953-7562(09)81067-8}, url = {http://www.sciencedirect.com/science/article/pii/S0953756209810678}, author = {Georges Blaha and Geoffrey Hall and Jeffry S. Warokka and Erlene Concibido and Carlos Ortiz-Garcia} } @article {4680, title = {Phytophthora agathidicida: research progress, cultural perspectives and knowledge gaps in the control and management of kauri dieback in New Zealand}, journal = {Plant Pathology}, volume = {69}, year = {2020}, month = {Feb-01-2021}, pages = {3 - 16}, abstract = {

Kauri (Agathis australis), which is one of the world{\textquoteright}s largest and longest-living conifer species, is under threat from a root and collar dieback disease caused by the oomycete pathogen Phytophthora agathidicida. The noted incidence of kauri dieback has increased in the past decade, and even trees \>1000\ years old are not immune. This disease has profound effects on both forest ecosystems and human society, particularly indigenous M{\={a}}ori, for whom kauri is a taonga or treasure of immense significance. This review brings together existing scientific knowledge about the pathogen and the devastating disease it causes, as well as highlighting important knowledge gaps and potential approaches for disease management. The life cycle of P.\ agathidicida is similar to those of other soilborne Phytophthora pathogens, with roles for vegetative hyphae, zoospores and oospores in the disease. However, there is comparatively little known about many aspects of the biology of P.\ agathidicida, such as its host range and disease latency, or about the impact on the disease of abiotic and biotic factors such as soil health and co-occurring Phytophthora species. This review discusses current and emerging tools and strategies for surveillance, diagnostics and management, including a consideration of genomic resources, and the role these play in understanding the pathogen and how it causes this deadly disease. Key aspects of indigenous M{\={a}}ori knowledge, which include rich ecological and historical knowledge of kauri forests and a holistic approach to forest health, are highlighted.

}, issn = {0032-0862}, doi = {10.1111/ppa.v69.110.1111/ppa.13104}, url = {https://bsppjournals.onlinelibrary.wiley.com/doi/full/10.1111/ppa.13104}, author = {Bradshaw, R. E. and Bellgard, S. E. and Black, A. and Burns, B. R. and Gerth, M. L. and McDougal, R. L. and Scott, P. M. and Waipara, N. W. and Weir, B. S. and Williams, N. M. and Winkworth, R. C. and Ashcroft, T. and Bradley, E. L. and Dijkwel, P. P. and Guo, Y. and Lacey, R. F. and Mesarich, C. H. and Panda, P. and Horner, I. J.} } @article {Brasier2004823, title = {Production of gametangia by Phytophthora ramorum in vitro}, journal = {Mycological Research}, volume = {108}, number = {7}, year = {2004}, pages = {823 - 827}, abstract = {

Until now gametangia have not been obtained between paired European A1 and American A2 isolates of Phytopthora ramorum in vitro. Their production in artificial culture relies on interspecific pairings. Using P. drechsleri and P. cambivora testers, 51 of 110 P. ramorum isolates from across Europe were all shown to be A1s; while 32 of 38 American isolates from across California and southwest Oregon were shown to be A2s. However, these interspecific pairings are complex, unusually slow and unpredictable. A range of culture media and conditions are described that were tested, unsuccessfully, with a view to enhancing the efficiency of the interspecific pairings. In further tests, gametangia were obtained between A1 and A2 isolates of P. ramorum when juvenile, pre-chlamydospore producing mycelia were mixed together on carrot agar. The gametangia formed in 3{\textendash}10 d, sparsely to frequently, initially only within the boundaries of the mixed inocula but subsequently in the extended mycelial growth. Chlamydospores were also produced. This inoculum-mixing method, though again sometimes unpredictable, should enhance efficiency of testing for compatibility types and facilitate further studies on whether the sexual outcrossing system of P. ramorum is functional. Differences between sexual reproduction of P. ramorum and that of other heterothallic Phytophthora species are discussed.

}, issn = {0953-7562}, doi = {10.1017/S0953756204000565}, url = {http://www.sciencedirect.com/science/article/pii/S0953756208603949}, author = {Brasier,Clive and Susan Kirk} } @article {588, title = {Plant pathology: Sudden larch death}, journal = {Nature}, volume = {466}, year = {2010}, pages = {824-825}, chapter = {824}, doi = {10.1038/466824a}, url = {http://dx.doi.org/10.1038/466824a}, author = {Brasier,Clive and Webber,Joan} } @article { refId, title = {Phytophthora cinnamomi and oak decline in southern Europe. Environmental constraints including climate change}, journal = {Ann. For. Sci.}, volume = {53}, year = {1996}, pages = {347-358}, doi = {10.1051/forest:19960217}, url = {http://dx.doi.org/10.1051/forest:19960217}, author = {C.M. Brasier} } @article {brasier_phytophthora_2010, title = {Phytophthora lateralis discovered in an old growth Chamaecyparis forest in Taiwan.}, journal = {Plant pathology}, volume = {59}, number = {4}, year = {2010}, pages = {595{\textendash}603}, keywords = {phylogeny}, issn = {00320862}, doi = {http://dx.doi.org/10.1111/j.1365-3059.2010.02278.x}, author = {C.M. Brasier and A. Vannini and T.T. Chang and A.M. Vettraino} } @article {CambridgeJournals:249519, title = {Phytophthora alni sp. nov. and its variants: designation of emerging heteroploid hybrid pathogens spreading on Alnus trees}, journal = {Mycological Research}, volume = {108}, number = {10}, year = {2004}, pages = {1172-1184}, abstract = {

In 1993 a destructive new Phytophthora pathogen of riparian Alnus trees was discovered in the UK and subsequently shown to be present in other parts of Europe. The new Phytophthora comprised a group of emergent heteroploid hybrids, probably between P. cambivora and a species related to P. fragariae. These included a common, near tetraploid standard hybrid, the presumptive allopolyploid; and four scarcer major variant types with chromosome numbers intermediate between diploid and tetraploid, named the Swedish, Dutch, German and UK variants. The standard hybrid type is formally designated here as Phytophthora alni subsp. alni. The Swedish variant is designated as P. alni subsp. uniformis; and the Dutch, German and UK variants collectively as P. alni subsp. multiformis. The properties of the Dutch, German and UK variants within subsp. multiformis are informally described. The problems of designating emergent species hybrids under the International Code of Botanical Nomenclature and the reasons for the taxonomic choices made are discussed.

}, doi = {10.1017/S0953756204001005}, url = {http://dx.doi.org/10.1017/S0953756204001005}, author = {Clive M. Brasier and Kirk, S.A. and Jose Delcan and David E.L. Cooke and Thomas Jung and Man In{\textquoteright}t Veld, W.A.} } @article {Brasier2005853, title = {Phytophthora kernoviae sp. nov., an invasive pathogen causing bleeding stem lesions on forest trees and foliar necrosis of ornamentals in the UK}, journal = {Mycological Research}, volume = {109}, number = {8}, year = {2005}, pages = {853 - 859}, abstract = {

A new Phytophthora pathogen of trees and shrubs, previously informally designated Phytophthora taxon C, is formally named here as P. kernoviae. P. kernoviae was discovered in late 2003 during surveys of woodlands in Cornwall, south-west England, for the presence of another invasive pathogen, P. ramorum. P. kernoviae is self-fertile (homothallic), having plerotic oogonia, often with distinctly tapered stalks and amphigynous antheridia. It produces papillate sporangia, sometimes markedly asymmetric with medium length pedicels. Its optimum temperature for growth is ca 18 ${\i}nfty$C and upper limit ca 26${\i}nfty$. Currently, P. kernoviae is especially noted for causing bleeding stem lesions on mature Fagus sylvatica and foliar and stem necrosis of Rhododendron ponticum. P. kernoviae is the latest of several invasive tree Phytophthoras recently identified in the UK. Its geographical origins and the possible plant health risk it poses are discussed.

}, issn = {0953-7562}, doi = {DOI: 10.1017/S0953756205003357}, url = {http://www.sciencedirect.com/science/article/B7XMR-4RS503Y-5/2/2264e8910ee36f4e72255d6160ebf9e4}, author = {Clive M. Brasier and Paul A. Beales and KIRK,Susan A. and Denman,Sandra and Joan Rose} } @conference {brasier2002pathogenicity, title = {Pathogenicity of Phytophthora ramorum isolates from North America and Europe to bark of European Fagaceae, American Quercus rubra and other forest trees}, booktitle = {Sudden oak death, a science symposium - the state of our knowledge, USDA Forest Service and University of California, Berkeley.}, year = {2002}, pages = {30{\textendash}31}, author = {C.M. Brasier and Rose, J. and Kirk, S.A. and Webber, JF} } @article {4630, title = {Phytophthora species recovered from the Connecticut River Valley in Massachusetts, USA}, journal = {Mycologia}, volume = {108}, year = {2016}, month = {Aug-01-2017}, pages = {6 - 19}, abstract = {

Little is currently known about the assemblage of Phytophthora species in northeastern North America, representing a gap in our understanding of species incidence. Therefore, Phytophthora species were surveyed at 20 sites in Massachusetts, with 16 occurring in the Connecticut River Valley. Many of the sampled waterways were adjacent to active agricultural lands, yet were buffered by mature floodplain forests composed of Acer, Platanus, Populus and Ulmus. Isolates were recovered with three types of baits (rhododendron leaves, pear, green pepper) in 2013 and water filtration in 2014. Overall, 457 isolates of Phytophthora were recovered and based on morphological characters and rDNA internal transcribed spacer (ITS), β-tubulin (β-tub) and cytochrome oxidase c subunit I (cox1) sequences, 18 taxa were identified, including three new species: P. taxon intercalaris, P. taxon caryae and P. taxon pocumtuck. In addition, 49 isolates representing five species of Phytopythium also were identified. Water filtration captured a greater number of taxa (18) compared to leaf and fruit baits (12). Of the three bait types rhododendron leaves yielded the greatest number of isolates and taxa, followed by pear and green pepper, respectively. Despite the proximity to agricultural lands, none of the Phytophthora species baited are considered serious pathogens of vegetable crops in the region. However, many of the recovered species are known woody plant pathogens, including four species in the P. citricola s.l. complex that were identified: P. plurivora, P. citricola III, P. pini and a putative novel species, referred to here as P. taxon caryae. An additional novel species, P. taxon pocumtuck, is a close relative of P. borealis based on cox1 sequences. The results illustrate a high level of Phytophthora species richness in the Connecticut River Valley and that major rivers can serve as a source of inoculum for pathogenic Phytophthora species in the northeast.

}, issn = {0027-5514}, doi = {10.3852/15-038}, url = {https://www.tandfonline.com/doi/full/10.3852/15-038}, author = {Brazee, Nicholas J. and Wick, Robert L. and Hulvey, Jonathan P.} } @article {4258, title = {Phytophthora palmivora}, volume = {Number 12}, year = {2005}, pages = {2 pp}, publisher = {American Samoa Community College Community \& Natural Resources Cooperative Research \& Extension }, abstract = {

The organism that caused the 1845-46 Irish Potato Famine was named Phytophthora, the {\textquotedblleft}plant destroyer{\textquotedblright}. Though initially considered a fungus, or water mold, this organism is more like certain algae and has been moved from the kingdom Fungi to Chromista. There are about 80 species of Phytophthora, all damaging to plants. One of the most common tropical species is P. palmivora, with more than 150 plant hosts. Some of the most important hosts are black pepper (Piper nigrum), rubber (Hevea brasilensis), durian (Durio zibethinus), coconut (Co- cos nucifera), cocoa (Theobroma cacao), breadfruit (Artocarpus altilis), and papaya (Carica papaya). In American Samoa, the last three hosts are attacked by P. palmivora.

}, url = {http://www2.ctahr.hawaii.edu/adap/ASCC_LandGrant/Dr_Brooks/BrochureNo12.pdf}, author = {Brooks, F} } @mastersthesis {1305, title = {A Phytophthora-induced disease of English holly, Ilex aquifolium L.}, volume = {MS}, year = {1954}, school = {Oregon State University}, type = {masters}, address = {Corvallis}, author = {Buddenhagen, I. W.} } @article {486, title = {Phytophthora cinnamomi and Australia{\textquoteright}s biodiversity: impacts, predictions and progress towards control.}, journal = {Australian Journal of Botany}, volume = {56}, year = {2008}, pages = {279{\textendash}310}, doi = {10.1071/BT07159}, url = {http://dx.doi.org/10.1071/BT07159}, author = {Cahill, DM and Rookes, JE and Wilson, BA and Gibson, L and McDougall, KL} } @article {{\v c}ern{\'y}2008phytophthora, title = {Phytophthora cambivora causing ink disease of sweet chestnut recorded in the Czech Republic}, journal = {Czech Mycol.}, volume = {60}, year = {2008}, pages = {265{\textendash}274}, abstract = {

Castanea sativa is a non-autochthonous but commonly planted ornamental tree in the Czech Republic. It is sensitive to some Phytophthora infections causing the so-called ink disease. The disease usually occurs in warmer regions in Europe. In the Czech Republic it had not been detected until the nineties of the 20th century. In 1997 extensive decline of a sweet chestnut ornamental orchard with typical symptoms of ink disease was found at one locality in eastern Bohemia. Later the causal organism of this disease, Phytophthora cambivora, was isolated from necrotised tissues of trunks of several declining chestnut trees. This is the first find of the pathogen causing ink disease of chestnut in the Czech Republic.

}, issn = {0009-0476}, url = {http://www.natur.cuni.cz/cvsm/CM60210.pdf}, author = {Cerny, K. and Gregorov{\'a}, B. and Strnadov{\'a}, V. and Tom{\v s}ovsky, M. and Holub, V. and Gabrielov{\'a}, {\v S}.} } @article {EFP:EFP735, title = {Phytophthora ramorum in England and Wales: which environmental variables predict county disease incidence?}, journal = {Forest Pathology}, year = {2011}, pages = {no{\textendash}no}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum is the oomycete pathogen responsible for Sudden Oak Death on the West Coast of the USA and Sudden Larch Death in the British Isles. It also causes twig dieback and leaf blight on a series of ornamental hosts (e.g. Rhododendron, Viburnum, Pieris and Camellia) commonly grown in plant nurseries, traded by garden centres and cultivated in public and private gardens. The role of the plant trade in the dispersal of P. ramorum has been well documented, but there is a need for regional analyses of which environmental variables can predict disease expression in the trade and in the wild, so as to be able to better predict the further development of this worldwide plant health issue. In this study, we analyse data on the incidence of P. ramorum (2002{\textendash}2009, thus before the reports in Japanese larch plantations) in counties in England and Wales as a function of environmental variables such as temperature and rainfall, controlling for confounding factors such as county area, human population and spatial autocorrelation. While P. ramorum county incidence in nurseries and retail centres was positively related to county area and human population density, county incidence in gardens and the wild did not show such correlations, declined significantly towards the East and was positively correlated with disease incidence in the trade. The latter finding, although not conclusively proving causation, suggests a role of the trade in the dispersal of this pathogen across English and Welsh landscapes. Combined together, P. ramorum county incidence in the trade and in the semi-natural environment increased with increasing precipitation and with declining latitude. This study shows the importance of environmental variables in shaping regional plant epidemics, but also yields results that are suggestive of a role of people in spreading plant diseases across entire countries.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00735.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00735.x}, author = {Chadfield, V. and Pautasso, M.} } @article {4664, title = {Promise and Pitfalls of Endemic Resistance for Cultural Resources Threatened by Phytophthora ramorum}, journal = {Phytopathology}, volume = {109}, year = {2019}, month = {Jan-05-2019}, pages = {760 - 769}, abstract = {

Invasive forest pathogens can harm cultural, economic, and ecological resources. Here, we demonstrate the potential of endemic tree pathogen resistance in forest disease management using Phytophthora ramorum, cause of sudden oak death, in the context of management of tanoak (Notholithocarpus densiflorus), an ecologically unique and highly valued tree within Native American communities of northern California and southern Oregon in the United States. We surveyed resistance to P. ramorum on the Hoopa Valley Indian Reservation and Yurok Indian Reservation in a set of study sites with variable management intensities. Variation in resistance was found at all sites with similar mean and variation across stands, and resistance tended to have a random spatial distribution within stands but was not associated with previous stand management (thinning or prescribed fire) or structural characteristics such as tree density, basal area, or pairwise relatedness among study trees. These results did not suggest host, genetic, management, or environment interactions that could be easily leveraged into treatments to increase the prevalence of resistant trees. We applied epidemiological models to assess the potential application of endemic resistance in this system and to examine our assumption that in planta differences in lesion size{\textemdash}our measure of resistance{\textemdash}reflect linkages between mortality and transmission (resistance) versus reduced mortality with no change in transmission (tolerance). This assumption strongly influenced infection dynamics but changes in host populations{\textemdash}our conservation focus{\textemdash}was dependent on community-level variation in transmission. For P. ramorum, slowing mortality rates (whether by resistance or tolerance) conserves host resources when a second source of inoculum is present; these results are likely generalizable to pathogens with a broader host range. However, when the focal host is the sole source of inoculum, increasing tolerant individuals led to the greatest stand-level pathogen accumulation in our model. When seeking to use variation in mortality rates to affect conservation strategies, it is important to understand how these traits are linked with transmission because tolerance will be more useful for management in mixed-host stands that are already invaded, compared with single-host stands with low or no pathogen presence, where resistance will have the greatest conservation benefits.

}, issn = {0031-949X}, doi = {10.1094/PHYTO-04-18-0142-R}, url = {https://apsjournals.apsnet.org/doi/pdf/10.1094/PHYTO-04-18-0142-R}, author = {Cobb, Richard C. and Ross, Noam and Hayden, Katherine J. and Eyre, Catherine A. and Dodd, Richard S. and Frankel, Susan J. and Garbelotto, Matteo and Rizzo, David M.} } @proceedings {369, title = {Phytophthora siskiyouensis on alders in southern California: an update.}, year = {2009}, pages = {pg 46-47}, publisher = {California Forest Pest Council. Meeting Abstracts}, address = {Heidrick Ag Center, Woodland, California}, author = {Coffey, M. D. and D. M. Mathews} } @article {4251, title = {Phylogenetic analysis of Phytophthora species based on ITS1 and ITS2 sequences of the ribosomal RNA gene repeat}, journal = {Mycological Research}, volume = {101}, year = {1997}, month = {Jan-06-1997}, pages = {667 - 677}, abstract = {

The internal transcribed spacer regions (ITS1 and ITS2) of the ribosomal RNA gene repeat from Phytophthora species were amplified using the polymerase chain reaction and sequenced. Sequences from P. cambivora, P. cinnamomi, P. citricola, P. cryptogea, P. drechsleri, P. fragariae var. fragariae, P. fragariae var. rubi, P. megasperma var. megasperma and P. nicotianae were compared with published sequences and phylogenetic trees were produced. The resultant grouping of species generally agreed with groupings established using classical morphological criteria, primarily sporangial morphology. Amongst species with non-papillate sporangia two clades were evident, one consisting of P. fragariae, P. cambivora and P. cinnamomi and the other of P. megasperma, P. drechsleri and P. cryptogea. The latter three were placed in the tree between the non-papillate groups and the papillate and semi-papillate groups which formed three distinct clades. One group comprised P. citricola, P. citrophthora and P. capsici, another P. megakarya and P. palmivora and a third P. pseudotsugae, P. cactorum, P. idaei, P. nicotianae and P. infestans. More isolates of P. megasperma, P. drechsleri and P. cryptogea will need to be examined to settle more precisely the relationship of these species to the others. PCR amplification of ITS sequences using freeze-thawed mycelial scrapings from pure cultures growing on agar followed by digestion with restriction enzymes is a quick and easy way to compare and identify isolates without the need for laborious DNA extraction procedures. With improved technology, rapid automatic sequencing of PCR-amplified ITS regions is now possible and yields detailed information of relationships within the genus as well as allowing the design of species-specific PCR primers for diagnostic purposes.

}, issn = {09537562}, doi = {10.1017/S0953756296003218}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0953756208604888}, author = {Cooke, David E.L. and Duncan, James M.} } @article {4381, title = {Phytophthora tentaculata su gerbera in Italia}, journal = {Informatore Fitopatologico }, volume = {56}, year = {2006}, pages = {23-25}, abstract = {

During spring 2002, gerbera (Gerbera jamesonii) plants showing blighted leaves and crown and stem rot symptoms were observed in a commercial gerbera planting located at Torre del Greco, near Naples. A Phytophthora sp. was consistently isolated from stem and collar tissues of symptomatic plants. The isolated oomycete was later further investigate, using traditional and polymerase chain reaction (PCR)-based methods to determine species identity, as well as to test pathogenicity. On V8a-juice agar medium at 21{\textpm}1{\textdegree}C, the observed morphological characters were similar to those of P. tentaculata whereas colony growth ceased at 32-34{\textdegree}C. Sequence analysis of PCR-amplified nuclear ribosomal DNA (rDNA), which includes the internal transcribed spacer (ITS) regions, ITS1 and ITS2 and 5.8S, obtained in template DNA extracted from pure culture fresh mycelium, revealed that the Italian Phytophthora sp. infecting gerbera was most closely related to P. tentaculata infecting Chrysanthemum, which had been reported from Germany. Also, extensive restriction fragment length polymorphism (RFLP) analysis of the rDNA repeat (ITS1, 5.8S and ITS2), using several restriction endonucleases, showed that the gerbera-infecting oomycete differed from several other Phytophthora species used for comparison, and had restriction fragments identical to those known from the German P. tentaculata. Thus, on the basis of biological, morphological and molecular data obtained, the chromist infecting gerbera in Italy was identified as P. tentaculata. Also, it proved to be the causal agent of crown and stem rot of gerbera according to Koch{\textquoteright}s rule fulfilment. This is the first report of the presence of P. tentaculata in Italy and further extends knowledge on the natural host range of such chromist.

}, issn = {0020-0735}, url = {http://www.cabdirect.org/abstracts/20063066005.html;jsessionid=C23F9F14D93FF641EEE94948EFEB99D5}, author = {Cristinzio, G and Camele, I and Marcone, C} } @article {PPA:PPA1718, title = {Phytophthora alni causing decline of black and grey alders in the Czech Republic}, journal = {Plant Pathology}, volume = {57}, number = {2}, year = {2008}, pages = {370{\textendash}370}, publisher = {Blackwell Publishing Ltd}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2007.01718.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2007.01718.x}, author = {Černy, K. and Gregorova, B. and Strnadov{\'a}, V. and Holub, V. and Tomsovsky, M. and Cervenka, M.} } @article {631, title = {Phytophthora alder decline: disease symptoms, causal agent and its distribution in the Czech Republic}, journal = {Plant Protect. Sci.}, volume = {46}, year = {2010}, pages = {12-18}, abstract = {

Phytophthora decline of riparian alder populations has recently become an important problem in many European countries, including the Czech Republic. The causal agent, Phytophthora alni, has spread quickly in the Czech Republic. Hundreds of kilometres of riparian alder stands, especially in the western part of the country, have been severely affected to date. Diseased trees show symptoms characteristic of Phytophthora root and collar rot; these include small, sparse and yellowing foliage, crown dieback, presence of exudates on the bark and necroses of collar and root tissues. Infected trees usually die within a few years, or they become irreversibly damaged, and their function in bank reinforcement declines. The ecological and mechanical functioning of severely affected alder stands may be seriously disrupted.

}, keywords = {alder decline, Alnus glutinosa, Alnus incana, bleeding canker, common alder, Czech Republic, grey alder, Phytophthora alni}, url = {http://www.agriculturejournals.cz/web/pps.htm?volume=46\&firstPage=12\&type=publishedArticle}, author = {Černy, K. and Strnadov{\'a}, V.} } @article {davidsonpathways, title = {Pathways of movement for Phytophthora ramorum, the causal agent of Sudden Oak Death}, journal = {The American Phytopathological Society Sudden Oak Death Online Symposium}, year = {2003}, publisher = {American Phytopathological Society}, author = {J. M. Davidson and Shaw, C.G.T.} } @article {EPP:EPP2243, title = {Phytophthora ramorum and Phytophthora kernoviae on naturally infected asymptomatic foliage}, journal = {EPPO Bulletin}, volume = {39}, number = {1}, year = {2009}, pages = {105{\textendash}111}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum and Phytophthora kernoviae are recently discovered invasive Phytophthoras causing leaf necrosis and shoot tip dieback mostly on ornamental and forest understorey species, but also cause bleeding cankers on stems of a wide range of tree species. Sporulation occurs only on infected shoots or fruits and foliage so foliar hosts are central to the disease epidemiology. In field trials to assess infection in trap plants exposed to natural inoculum of P. ramorum and P. kernoviae on rhododendron in south west England, it was discovered that leaves of the trap plants (Rhododendron {\textquoteleft}Cunninghams White{\textquoteright}) and holm oak (Quercus ilex) were asymptomatically infected and supported sporulation of both pathogens. More than half the rhododendron trap plants exposed to inoculum of P. kernoviae became infected compared with approximately a third of those exposed to P. ramorum in a natural situation. Approximately one third of the infections were detected from asymptomatic foliage for both pathogens. The significance of these findings for plant health regulation based on visual inspection as a measure to prevent introduction and dissemination of both these pathogens is explored and research gaps identified.

}, issn = {1365-2338}, doi = {10.1111/j.1365-2338.2009.02243.x}, url = {http://dx.doi.org/10.1111/j.1365-2338.2009.02243.x}, author = {Denman, S. and Kirk, S.A. and Moralejo, E. and Webber, JF} } @inbook {4136, title = {Phytophthora diseases of Theobroma cacao}, booktitle = {Improvement of cocoa tree resistance to Phytophthora diseases}, year = {2004}, pages = {15{\textendash}44}, publisher = {CIRAD}, organization = {CIRAD}, address = {Montpellier, France}, author = {Despreaux, Denis}, editor = {Cilas, C. and Despreaux, Denis} } @article {4230, title = {Pathogenicity of Phytophthora pluvialis to Pinus radiata and its relation with red needle cast disease in New Zealand}, journal = {New Zealand Journal of Forestry Science}, volume = {44}, year = {2014}, month = {Jan-01-2014}, pages = {6}, abstract = {

Background

Red needle cast, a new foliage disease of Pinus radiata in New Zealand is described. The disease has been variable in incidence and severity both regionally and in different years. The early symptoms of discrete olive coloured lesions, often with a narrow dark resinous mark or band, were first recognised in winter of 2008 in plantation forests on the eastern coast of the North Island. These lesions develop further to result in rapid needle senescence and premature defoliation. The disease has been termed red needle cast in New Zealand as affected trees have a reddish appearance prior to the casting of the needles. The subsequent four years of monitoring have confirmed that, depending on location, symptoms are first observed in late autumn through late winter. Newly developing spring and summer foliage is seldom affected. Isolation from needles using a Phytophthora-selective medium frequently yielded an unknown species of Phytophthora which was subsequently found to be identical to Phytophthora pluvialis, a species described from Oregon, USA in 2013 where it is not associated with disease. Infection appears to be limited to the needles with no recoveries of Phytophthora pluvialis having been made from the roots, stems or branches. Occasionally a second species of Phytophthora, P. kernoviae, was also recovered from needles with the same symptoms.

Methods

Needle symptoms were described in the field from 2008-2012 with isolation onto Phytophthora selective media. Koch{\textquoteright}s postulates was completed on potted plants and detached needles.

Results

Symptoms were reproduced on both detached needles and potted plants of Pinus radiata when inoculated with zoospore suspensions of Phytophthora pluvialis.

Conclusions

This paper presents evidence that Phytophthora pluvialis is the primary cause of red needle cast in New Zealand.

}, issn = {1179-5395}, doi = {10.1186/s40490-014-0006-7}, url = {http://www.nzjforestryscience.com/content/44/1/6}, author = {Dick, Margaret and Williams, Nari and Bader, Martin and Gardner, Judy and Bulman, Lindsay} } @article {481, title = {Phytophthora pinifolia sp. nov. associated with a serious needle disease of Pinus radiata in Chile}, journal = {Plant Pathology}, volume = {57}, year = {2008}, pages = {715{\textendash}727}, abstract = {

During the course of the past three years, a new disease of ,em\>Pinus radiata, referred to as {\textquoteleft}Da{\~n}o Foliar del Pino{\textquoteright} (DFP) has appeared in the Arauco province of Chile and subsequently spread to other areas. The disease is typified by needle infections, exudation of resin at the bases of the needle brachyblasts and, in younger trees, necrotic lesions in the cambium, which eventually girdle the branches. The disease causes the death of young seedlings and mature trees can also succumb after a few years of successive infection, probably hastened by opportunistic fungi such as ,em\>Diplodia pinea. Isolations on selective medium for Phytophthora spp. led to the consistent isolation of a Phytophthora sp. from needle tissue. DNA sequence comparisons for the ITS rDNA and cox II gene regions, and morphological observation showed that this oomycete represents a previously undescribed species for which the name Phytophthora pinifolia sp. nov. is provided. This new species is characterized by unbranched sporangiophores, and non-papillate, sub-globose to ovoid sporangia that are occasionally free from the sporangiophore with medium length pedicels. Despite using a number of oospore inducing techniques, oogonia/antheridia were not observed in isolates of P. pinifolia. Pathogenicity trials with P. pinifolia showed that it is pathogenic to P. radiata and causes rapid death of the succulent apical parts of young plants. Phytophthora pinifolia is the first Phytophthora known to be associated with needles and shoots of a Pinus sp. and its aerial habit is well matched with the occurrence and symptoms of DFP in Chile.

}, keywords = {Monterey pine, oomycete phylogeny, plantation forestry}, doi = {10.1111/j.1365-3059.2008.01893.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2008.01893.x}, author = {Dur{\'a}n, A. and Gryzenhout, M. and Slippers, B. and Ahumada, R. and Rotella, A. and Flores, F. and Wingfield, B. D. and Wingfield, M. J.} } @article {EFP:EFP627, title = {Phenotypic differences among three clonal lineages of Phytophthora ramorum}, journal = {Forest Pathology}, volume = {41}, number = {1}, year = {2011}, pages = {7{\textendash}14}, publisher = {Blackwell Publishing Ltd}, abstract = {

There are three major clonal lineages of Phytophthora ramorum present in North America and Europe named NA1, NA2, and EU1. Twenty-three isolates representing all three lineages were evaluated for phenotype including (i) aggressiveness on detached Rhododendron leaves and (ii) growth rate at minimum, optimum, and maximum temperatures. Closely related species P. foliorum and P. hibernalis were included in phenotypic tests since these species are encountered in nursery surveys for P. ramorum. Isolates from the NA2 and EU1 lineages were the most aggressive and isolates from the NA1 group were the least aggressive. The NA1 lineage of P. ramorum was the most variable in aggressiveness and growth rate. The variability in the NA1 lineage was due to the presence of non-wild type (nwt) isolates. There was no significant difference in growth rate among NA1 wild type (wt), NA2, and EU1 lineages at any temperature tested. The difference between wt and nwt P. ramorum isolates is discussed.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2009.00627.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2009.00627.x}, author = {Elliott, M. and Sumampong, G. and Varga, A. and Shamoun, S. F. and James, D. and Masri, S. and N. J. Gr{\"u}nwald} } @article {EFP:EFP586, title = {PCR-RFLP markers identify three lineages of the North American and European populations of Phytophthora ramorum}, journal = {Forest Pathology}, volume = {39}, number = {4}, year = {2009}, pages = {266{\textendash}278}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum, the cause of sudden oak death and ramorum blight, has three major clonal lineages and two mating types. Molecular tests currently available for detecting P. ramorum do not distinguish between clonal lineages and mating type is determined by cultural methods on a limited number of samples. In some molecular diagnostic tests, cross-reaction with other closely related species such as P. hibernalis, P. foliorum or P. lateralis can occur. Regions in the mitochondrial gene Cox1 are different among P. ramorum lineages and mitochondrial genotyping of the North American and European populations seems to be sufficient to differentiate between mating types, because the EU1 lineage is mostly A1 and both NA1 and NA2 lineages are A2. In our study, we were able to identify P. ramorum isolates according to lineage using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) of the Cox1 gene, first by using ApoI to separate P. ramorum from other species and EU1 from North American populations, and then AvaI to distinguish between NA1 and NA2 genotypes. However, P. foliorum had the same restriction profile as P. ramorum NA1 isolates.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2008.00586.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2008.00586.x}, author = {Elliott, M. and Sumampong, G. and Varga, A. and Shamoun, S. F. and James, D. and Masri, S. and Bri{\`e}re, S. C. and N. J. Gr{\"u}nwald} } @book {117, title = {Phytophthora diseases worldwide.}, year = {1996}, pages = {562 pp}, publisher = {APS Press, American Phytopathological Society}, organization = {APS Press, American Phytopathological Society}, address = {St. Paul, MN}, author = {Erwin, D.C and Ribeiro, O.K.} } @article {PPA:PPA2471, title = {Phosphite primed defence responses and enhanced expression of defence genes in Arabidopsis thaliana infected with Phytophthora cinnamomi}, journal = {Plant Pathology}, volume = {60}, number = {6}, year = {2011}, pages = {1086{\textendash}1095}, publisher = {Blackwell Publishing Ltd}, abstract = {

This paper describes the effect of phosphite (Phi), a systemic chemical, on the induction of defence responses in Phytophthora cinnamomi-infected Arabidopsis thaliana accessions Ler and Col-0. Application of Phi to non-inoculated A. thaliana seedlings of accession Ler elevated transcription of defence genes in the salicylic acid (PR1 and PR5) and jasmonic acid/ethylene (THI2.1 and PDF1.2) pathways. Furthermore, a systemic increase in the expression of the PR1 gene was demonstrated in Phi-treated seedlings using the transgenic line PR1::GUS in the presence/absence of the pathogen by 72 h after inoculation. The cells of Phi-treated A. thaliana Ler leaves responded to P. cinnamomi zoospore inoculation with a rapid increase in callose deposition and hydrogen peroxide (H2O2) production. Phi treatment resulted in the production of callose papillae 6 h earlier than in non-Phi-treated inoculated seedlings and enhanced the production of H2O2 in the leaves of A. thaliana at the site of hyphal penetration and in cells away from the inoculation point. By 24 h after infection, clear differences in the amount of H2O2 production were observed between the Phi-treated and non-Phi-treated plants. These rapid host responses did not occur in non-Phi-treated inoculated seedlings. There was also a significant (P \< 0{\textperiodcentered}001) decrease in lesion size in Phi-treated plants. These results indicate that Phi primes the plant for a rapid and intense response to infection involving heightened activation of a range of defence responses.

}, keywords = {callose deposition, defence response, hydrogen peroxide, potassium phosphonate (phosphite), reactive oxygen species (ROS)}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2011.02471.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2011.02471.x}, author = {Eshraghi, L. and Anderson, J. and Aryamanesh, N. and Shearer, B. and McComb, J. and Hardy, G. E. StJ. and O{\textquoteright}Brien, P. A.} } @proceedings {680, title = {Persistence of Phytophthora ramorum and Phytophthora kernoviae in U.K. natural areas and implications for North American forests}, volume = {Gen. Tech. Rep. PSW-GTR-229}, year = {2009}, month = {04/2010}, pages = {83-84}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station.}, address = {Santa Cruz, California}, author = {Elizabeth J. Fichtner and Rizzo, David M. and Webber,Joan and Kirk, Susan A. and Alistair Whybrow}, editor = {Susan J. Frankel and John T. Kliejunas and Katharine M. Palmieri} } @proceedings {944, title = {Proceedings of the sudden oak death second science symposium: the state of our knowledge}, year = {2005}, month = {2006}, pages = {571 pp.}, publisher = {Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture}, address = {Monterey, California}, abstract = {

The Sudden Oak Death Second Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Ninety papers and forty-six posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland management, monitoring, ecology, and diagnostics. Several papers on P. kernoviae and other forest Phytophthora species are also presented.

}, keywords = {coast live oak, invasive species, Phytophthora ramorum, Sudden oak death, tanoak}, url = {http://www.fs.fed.us/psw/publications/documents/psw_gtr196/}, author = {Frankel, Susan J. and Shea, Patrick J. and Haverty, Michael I.} } @article {4382, title = {Pest Alert: Phytophthora tentaculata.}, number = {December 18 2015}, year = {2015}, publisher = {Pacific Southwest Research Station, USDA Forest Service}, address = {Albany, CA . }, abstract = {

Phytophthora tentaculata has been detected in several California native plant nurseries and restoration sites. These are the first detections of P. tentaculata in the USA. Phytophthora tentaculata was initially noticed in a native plant nursery causing a severe root and crown rot in sticky monkey flower, Diplacus aurantiacus subsp. aurantiacus (Scrophulariaceae) in 2012 (figure 1). Since then it has been detected in four additional nurseries in three counties in CA in addition to three restoration sites where outplanted stock was found to be infected.

}, url = {http://www.suddenoakdeath.org/wp-content/uploads/2015/02/P.tentaculata.Pest_.Alert_.022315.pdf}, author = {Frankel, S and Swiecki, T and Bernhardt, E and Rooney-Latham, S and Blomquist, C} } @proceedings {945, title = {Proceedings of the sudden oak death fourth science symposium.}, year = {2009}, month = {2010}, pages = {378 pp.}, publisher = {Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture}, address = {Santa Cruz, California}, abstract = {

The Sudden Oak Death Fourth Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Ninety submissions describing papers or posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland management, monitoring, ecology, and diagnostics.

}, keywords = {coast live oak, invasive species, Phytophthora ramorum, Sudden oak death, tanoak}, url = {http://www.fs.fed.us/psw/publications/documents/psw_gtr229/}, author = {Susan J. Frankel and John T. Kliejunas and Katharine M. Palmieri} } @proceedings {946, title = {Proceedings of the sudden oak death third science symposium}, year = {2007}, month = {2008}, pages = {491 pp.}, publisher = {Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture}, address = {Santa Rosa, California}, abstract = {

The Sudden Oak Death Third Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. One hundred and seventeen submissions describing papers and posters on the following sudden oak death/ P. ramorum topics are included: biology, genetics, nursery, and wildland management, monitoring, ecology, and diagnostics.

}, keywords = {coast live oak, invasive species, Phytophthora ramorum, Sudden oak death, tanoak}, url = {http://www.fs.fed.us/psw/publications/documents/psw_gtr214/}, author = {Frankel, Susan J. and Kliejunas, John T. and Palmieri, Katharine M.} } @article {4710, title = {Phytophthora Introductions in Restoration Areas: Responding to Protect California Native Flora from Human-Assisted Pathogen Spread}, journal = {Forests}, volume = {11}, year = {2020}, month = {Nov-30-2020}, pages = {1291}, abstract = {

Over the past several years, plantings of California native plant nursery stock in restoration areas have become recognized as a pathway for invasive species introductions, in particular Phytophthora pathogens, including first in the U.S. detections (Phytophthora tentaculata, Phytophthora quercina), new taxa, new hybrid species, and dozens of other soilborne species. Restoration plantings may be conducted in high-value and limited habitats to sustain or re-establish rare plant populations. Once established, Phytophthora pathogens infest the site and are very difficult to eradicate or manage{\textemdash}they degrade the natural resources the plantings were intended to enhance. To respond to unintended Phytophthora introductions, vegetation ecologists took a variety of measures to prevent pathogen introduction and spread, including treating infested areas by solarization, suspending plantings, switching to direct seeding, applying stringent phytosanitation requirements on contracted nursery stock, and building their own nursery for clean plant production. These individual or collective actions, loosely coordinated by the Phytophthoras in Native Habitats Work Group ensued as demands intensified for protection from the inadvertent purchase of infected plants from commercial native plant nurseries. Regulation and management of the dozens of Phytophthora species and scores of plant hosts present a challenge to the state, county, and federal agriculture officials and to the ornamental and restoration nursery industries. To rebuild confidence in the health of restoration nursery stock and prevent further Phytophthora introductions, a voluntary, statewide accreditation pilot project is underway which, upon completion of validation, is planned for statewide implementation.

}, doi = {10.3390/f11121291}, url = {https://www.mdpi.com/1999-4907/11/12/1291/htm}, author = {Frankel, Susan J. and Conforti, Christa and Hillman, Janell and Ingolia, Mia and Shor, Alisa and Benner, Diana and Alexander, Janice M. and Bernhardt, Elizabeth and Swiecki, Tedmund J.} } @article {4364, title = {Phytophthora heveae, a pathogen of kauri}, journal = {New Zealand Journal of Forestry Science}, volume = {4}, year = {1974}, pages = {59-63}, author = {Gadgil, P.D.} } @book {1307, title = {Phytophthora: identifying species by morphology and DNA fingerprints}, year = {2008}, pages = {158}, publisher = {American Phytopathological Society (APS Press)}, organization = {American Phytopathological Society (APS Press)}, address = {St. Paul, MN}, abstract = {

This book presents morphological (chapter 1) and DNA fingerprint (chapter 2) keys to various Phytophthora species, as well as a section that combines morphological details and DNA fingerprints for 59 Phytophthora species (chapter 3). Tabulated data on host range and geographic origin are included.

}, issn = {978-0-89054-364-1}, author = {Gallegly, M. E. and Hong, Chuanxue} } @article {4704, title = {Pathogenicity and infectivity of Phytophthora ramorum vary depending on host species, infected plant part, inoculum potential, pathogen genotype, and temperature}, journal = {Plant Pathology}, volume = {70}, year = {2021}, month = {Oct-19-2020}, pages = {287 - 304}, abstract = {

A total of 25 ornamental plant species representing 10 families were inoculated using three genotypes, each representing one of the genetic lineages NA1, NA2, and EU1 of the pathogen Phytophthora ramorum. Leaves were inoculated using suspensions with two zoospore concentrations and exposure at three temperatures, while stems were inoculated using agar plugs colonized by mycelia. Susceptibility was determined by measuring either the success of pathogen reisolation or lesion length caused by the pathogen. Infectivity was determined by counting sporangia in washes of inoculated leaves or stems. Results from all three pathogen genotypes combined were used to rank each of the 25 plant species for susceptibility and infectivity, while pooled results per genotype from all 25 hosts combined were employed for a preliminary comparison of pathogenicity and infectivity among genotypes. Statistical analyses showed that leaf results were affected by the concentration of zoospores, temperature, plant host, pathogen genotype, and by the interaction between host and pathogen genotype. Stem results were mostly affected by host and by the interaction between host and pathogen genotype. Hosts ranked differently when looking at the various parameters, and differences in rankings were also significant when comparing stem and leaf results. Differences were identified among the 25 hosts and the three pathogen genotypes for all parameters: results can be used for decision-making regarding regulations or selection of plants to be grown where infestations by P. ramorum are an issue.

}, issn = {0032-0862}, doi = {10.1111/ppa.v70.210.1111/ppa.13297}, url = {https://bsppjournals.onlinelibrary.wiley.com/doi/10.1111/ppa.13297}, author = {Garbelotto, Matteo and Schmidt, Doug and Popenuck, Tina} } @article {952, title = {Phosphonate controls sudden oak death pathogen for up to 2 years.}, journal = {California Agriculture}, volume = {63}, year = {2009}, pages = {10-17}, abstract = {

Since its emergence in the late 1990s, sudden oak death has killed mature oak trees and tanoaks in 14 California counties. Treatment options are now available to safeguard these trees from infection by Phytophthora ramorum, the aggressive and exotic pathogen responsible for sudden oak death. We provide an update on current knowledge regarding this emergent disease in California, and present results from three controlled experiments of two chemical treatments to manage the disease in oaks and tanoaks. Phosphonate treatments, legally registered in California to control sudden oak death, were effective in slowing both infection and growth rates for at least 18 months. Conversely, an alternative method consisting of an azomite soil amendment and bark lime wash was always ineffective, and did not reduce either growth or infection rates.

}, doi = {10.3733/ca.v063n01p10}, url = {http://ucanr.org/repository/cao/landingpage.cfm?article=ca.v063n01p10\&fulltext=yes$\#$}, author = {Matteo M. Garbelotto and Douglas J. Schmidt} } @article {4191, title = {Phytophthora acerina sp. nov., a new species causing bleeding cankers and dieback of Acer pseudoplatanus trees in planted forests in northern Italy}, journal = {Plant Pathology}, volume = {63}, year = {2013}, month = {08/2014}, pages = {858{\textendash}876}, abstract = {

A severe dieback of Acer pseudoplatanus trees was noticed in planted forest stands in northern Italy in 2010. Affected trees showed collar rot and aerial bleeding cankers along the stems, leading to crown dieback and eventually death. An unknown Phytophthora species was consistently isolated from necrotic bark and xylem tissue and from rhizosphere soil. Based on its unique combination of morphological and physiological characters and phylogenetic analysis, this new taxon is here described as Phytophthora acerina sp. nov. Phylogenetic analysis of ITS, cox1 and β-tubulin gene regions demonstrated that P. acerina is unique and forms a separate cluster within the {\textquoteleft}P.\ citricola complex{\textquoteright}, closely related to P.\ plurivora. Phytophthora acerina is homothallic with smooth-walled oogonia, thick-walled, mostly aplerotic oospores with a high abortion rate, paragynous antheridia, and persistent, morphologically variable semipapillate sporangia. Four to 5-week-old cultures produced globose to subglobose, appressoria-like and coralloid hyphal swellings and characteristic stromata-like hyphal aggregations. Optimum and maximum temperatures for growth are 25{\textdegree}C and 32{\textdegree}C, respectively. Genetic uniformity of all 15 studied isolates and the apparent absence of this species in the extensive surveys of nurseries, forests and seminatural ecosystems conducted in the previous two decades across Europe indicate a recent clonal introduction to northern Italy. Under-bark inoculation tests demonstrated high aggressiveness of P.\ acerina to A.\ pseudoplatanus indicating that this pathogen might be a serious risk to maple plantations and forests in Europe.

}, keywords = {biosecurity, Clade 2, invasive, nursery pathway, phylogeny, Phytophthora citricola}, issn = {1365-3059}, doi = {10.1111/ppa.12153}, url = {http://dx.doi.org/10.1111/ppa.12153}, author = {Ginetti, B. and Moricca, S. and Squires, J. N. and Cooke, D. E. L. and Ragazzi, A. and Jung, T.} } @article {4632, title = {PhytophthoraTaxon Pgchlamydo is a Cause of Shoot Blight and Root and Collar Rot of Viburnum tinus in Italy}, journal = {Plant Disease}, volume = {98}, year = {2014}, month = {Jan-10-2014}, pages = {1432 - 1432}, abstract = {

The quarantine pathogen Phytophthora ramorum has recently been found on dying Viburnum tinus in the nursery area of Pistoia, central Italy (43{\textdegree}56'0" N, 11{\textdegree}1'0" E) (3). As part of a surveillance program aimed at detecting P. ramorum in this area, the Phytophthora taxon Pgchlamydo was consistently found associated with symptomatic V. tinus. The crowns of these plants were wilted, and some plants also showed root and collar rot and underbark necrosis. Water courses adjacent to the nursery with the infected V. tinus were tested for the pathogen. Samples from seven symptomatic plants were placed on a selective V8A-PARPNH medium within 24 h from sampling. Tissue pieces (2 mm2) of 12 baits (apple fruits) exposed for a week in water bodies were plated on the same medium. Cottony colonies arose after 2 to 3 days of incubation at 23{\textdegree}C in the dark and were transferred to potato dextrose agar (PDA) in purity. Mycelial DNA was extracted with a commercial kit (Sigma-Aldrich). The rDNA ITS region and a portion of the mtDNA cox1 gene were PCR-amplified and the amplicons digested with the restriction enzymes MspI and AluI (for the ITS region) and RsaI (for the cox1 gene region). Isolates R7 from V. tinus, and ES2M5, ES2M11, and ES1M12 from the water bodies belonged to the same taxon based on restriction analysis of both DNA regions coupled with ITS-rDNA sequence homology (GenBank Accession Nos. KJ396773 to 76). A BLAST search in GenBank found that all isolates had a 99\% identity in the ITS-rDNA with the Phytophthora ITS Clade 6 member P. taxon Pgchlamydo. Sporangia produced after incubation in filtered pond water for 24 h were mostly ovoid (sometimes obpyriform), non-papillate, non-caducous. Some sporangia were emptied with external proliferation and had hyphal swellings. Thirty sporangia were measured and averaged 42.4 {\textpm} 6.2 {\texttimes} 29.9 {\textpm} 3.5 μm (range 30.0 to 56.1 {\texttimes} 22.5 to 38.0), with a length/width ratio of 1.4 {\textpm} 0.2 (1.2 to 2.0), and exit pores of 11.7 {\textpm} 1.5 μm (9.0 to 14.6). Optimum colony growth on V8A at 30{\textdegree}C was 4.4 {\textpm} 0.4 mm day{\textendash}1, and the maximum temperature for growth was 32{\textdegree}C. Inoculation on twigs of Fagus sylvatica and V. tinus produced necrotic lesions of 2.6 {\textpm} 0.5 cm (2.1 to 3.5) and 4.7{\textpm} 0.5 cm (3.8 to 5.6) respectively after 3 weeks of incubation at 23{\textdegree}C in the dark. Inoculation on V. tinus leaves resulted in lesions averaging 3.3 {\textpm} 1.1 {\texttimes} 2.1 {\textpm} 0.6 cm (range 2 to 5 {\texttimes} 1.5 to 3) after 2 weeks of incubation at 23{\textdegree}C in the dark. Control plant material showed no symptoms.The Phytophthora taxon Pgchlamydo has been reported on several ornamental and woody species, including Arctostaphylos sp., Camellia spp., Laurus nobilis, Buxus sempervirens, Rhododendron sp., Arbutus unedo, Prunus sp., Pseudotsuga sp., and Sequoia sempervirens, in North America and Europe (1,2). This is the first report, to our knowledge, of this taxon on V. tinus in Italy. V. tinus is widely sold in European nurseries, and it is also one of the most common hosts of P. ramorum (4). The fact that V. tinus is a host for both oomycetes, and the two microorganisms induce a similar symptomology (wilt), might complicate the control efforts of the phytosanitary inspection services aimed at restricting P. ramorum foci in Europe.

}, issn = {0191-2917}, doi = {10.1094/PDIS-03-14-0282-PDN}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-03-14-0282-PDN}, author = {Ginetti, B. and Carmignani, S. and Ragazzi, A. and Moricca, S.} } @proceedings {3953, title = {Proceedings of the fourth meeting of the International Union of Forest Research Organizations (IUFRO) Working Party 07.02.09}, year = {2007}, pages = {334 p}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station}, address = {Monterey, California}, abstract = {

The fourth meeting of the International Union of Forest Research Organizations (IUFRO) Working Party S07.02.09, Phytophthoras in Forests and Natural Ecosystems provided a forum for current research on Phytophthora species worldwide. Seventy-eight submissions describing papers and posters on recent developments in Phytophthora diseases of trees and natural ecosystems in Europe, Australasia, and the Americas are included. Research topics covered are Phytophthora biodiversity, ecology, epidemiology, management, and host- pathogen interactions.

}, url = {http://www.iufro.org/science/divisions/division-7/70000/70200/70209/}, author = {Goheen, E. M. and Frankel, S.J. and Goheen, E. M. and Frankel, S.J.} } @article {10.1371/journal.ppat.1000583, title = {Population genetic analysis infers migration pathways of Phytophthora ramorum in US nurseries}, journal = {PLoS Pathog}, volume = {5}, number = {9}, year = {2009}, month = {09}, pages = {e1000583}, publisher = {Public Library of Science}, abstract = {

Author Summary

Sudden oak death, caused by the fungus-like pathogen Phytophthora ramorum, has caused devastating levels of mortality of live oak and tanoak trees in coastal California forests and in urban and suburban landscapes in the San Francisco Bay Area. This pathogen also causes non-lethal disease on popular ornamental plants, including rhododendrons, viburnums, and camellias. P. ramorum was discovered in California in the late 1990s and is exotic to the United States. Recently, presence of the disease in wholesale nurseries in California, Oregon, and Washington has led to shipments of diseased plants across the US, thus risking the introduction of the pathogen to other vulnerable forests. We examined the genetic diversity of this pathogen in US nurseries in order to better understand its evolution in nurseries and movement between states. We found that California populations were genetically different enough from Oregon and Washington populations that infestations of the pathogen found in nurseries in other states could be distinguished as having originated from California or the Northwest. Our inferences were consistent with trace forward investigations by regulatory agencies.

}, doi = {10.1371/journal.ppat.1000583}, url = {http://dx.doi.org/10.1371\%2Fjournal.ppat.1000583}, author = {Goss, Erica M. and Larsen, Meg and Chastagner, Gary A. and Givens, Donald R. and Gr{\"u}nwald, Niklaus J.} } @article {doi:10.1094/PHYTO-05-10-0133, title = {Phytophthora ramorum in Canada: evidence for migration within North America and from Europe}, journal = {Phytopathology}, volume = {101}, number = {1}, year = {2011}, pages = {166-171}, doi = {10.1094/PHYTO-05-10-0133}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-05-10-0133}, author = {Goss, Erica M. and Larsen, Meg and Vercauteren, Annelies and Werres, Sabine and Heungens, Kurt and Gr{\"u}nwald, Niklaus J.} } @article {4693, title = {Phytophthora ramorum in Canada: Evidence for Migration Within North America and from Europe}, journal = {Phytopathology}, volume = {101}, year = {2011}, month = {Jan-01-2011}, pages = {166 - 171}, abstract = {

Phytophthora ramorum, the cause of sudden oak death on oak and ramorum blight on woody ornamentals, has been reported in ornamental nurseries on the West Coast of North America from British Columbia to California. Long-distance migration of P. ramorum has occurred via the nursery trade, and shipments of host plants are known to have crossed the U.S.-Canadian border. We investigated the genotypic diversity of P. ramorum in Canadian nurseries and compared the Canadian population with U.S. and European nursery isolates for evidence of migration among populations. All three of the P. ramorum clonal lineages were found in Canada but, unexpectedly, the most common was the NA2 lineage. The NA1 clonal lineage, which has been the most common lineage in U.S. nurseries, was found relatively infrequently in Canada, and these isolates may have been the result of migration from the United States to Canada. The EU1 lineage was observed almost every year and shared multilocus genotypes with isolates from Europe and the United States. Estimation of migration rates between Europe and North America indicated that migration was higher from Europe to North America than vice versa, and that unidirectional migration from Europe to North America was more likely than bidirectional migration.

}, issn = {0031-949X}, doi = {10.1094/PHYTO-05-10-0133}, url = {https://apsjournals.apsnet.org/doi/10.1094/PHYTO-05-10-0133}, author = {Goss, Erica M. and Larsen, Meg and Vercauteren, Annelies and Werres, Sabine and Heungens, Kurt and Gr{\"u}nwald, Niklaus J.} } @article {4282, title = {Phytophthora austrocedrae emerges as a serious threat to juniper Juniperus communis in Britain}, journal = {Plant Pathology}, volume = {64}, year = {2015}, month = {Jan-04-2015}, pages = {456 - 466}, abstract = {

From 2011 to 2013, Phytophthora austrocedrae was isolated from diseased Juniperus communis exhibiting dieback and mortality at eight geographically separate sites in Scotland and northern England. The pathogen was also confirmed present either by standard PCR of the ITS locus and sequencing or by real-time PCR on J.\ communis with symptoms at a further 11 sites in northern Britain. Out of 167 J.\ communis sampled across the 19 sites, 154 had foliage dieback over all or part of the crown as a result of basal lesions, which extended up the stem. Thirteen sampled trees had aerial branch lesions or discrete stem lesions with no apparent connection to the base of the tree. At 13 sites, dieback was concentrated in areas of poor drainage and/or alongside streams and other watercourses. In artificial inoculation experiments, P.\ austrocedrae caused rapidly extending stem and root lesions on J.\ communis and was reisolated from these lesions. Lesions also developed on Chamaecyparis lawsoniana and Chamaecyparis nootkatensis but the pathogen was not reisolated. All P.\ austrocedrae isolates obtained from J.\ communis in Britain shared 100\% identity across the ITS locus but were distinct at one sequence position from P.\ austrocedrae isolates collected in Argentina from diseased Austrocedrus chilensis. This study provides clear evidence that P.\ austrocedrae is a primary pathogen of J.\ communis and now presents a significant threat to this species in Britain. Pathways for the emergence of P. austrocedrae in Britain, and possible ways in which the pathogen may have spread within the country, are discussed.

}, doi = {10.1111/ppa.2015.64.issue-210.1111/ppa.12253}, url = {http://doi.wiley.com/10.1111/ppa.2015.64.issue-2http://doi.wiley.com/10.1111/ppa.12253}, author = {Green, S. and Elliot, M. and Armstrong, A. and Hendry, S. J.} } @article {AlinaG.Greslebin01012005, title = {Phytophthora species from declining Austrocedrus chilensis forests in Patagonia, Argentina}, journal = {Mycologia}, volume = {97}, number = {1}, year = {2005}, pages = {218-228}, abstract = {

A survey of Phytophthora spp. in declining and healthy Austrocedrus chilensis forest was conducted to obtain an overview of the species that inhabit these forests. Seventeen declining and three healthy stands plus 11 associated streams were surveyed. Five Phytophthora species were recovered. P. syringae was the most common species isolated from soil and/or streams at nine declining sites and one healthy site. P. gonapodyides was isolated from streams only, at five declining sites. P. cambivora was isolated from soil and the undescribed taxa P. taxon Pgchlamydo{\textquoteright} and 22 P. taxon Raspberry{\textquoteright} were isolated from streams at one declining site each. The species were identified by ITS rDNA sequences and morphological features. Brief descriptions of each species and a discussion of their possible relationship with "mal del cipres" are presented.

}, doi = {10.3852/mycologia.97.1.218}, url = {http://www.mycologia.org/cgi/content/abstract/97/1/218}, author = {Greslebin, Alina G. and Hansen, Everett M. and Winton, Loretta M. and Rajchenberg, Mario} } @article {411, title = {Pathogenicity of Phytophthora austrocedrae on Austrocedrus chilensis and its relation with mal del cipr{\'e}s in Patagonia}, journal = {Plant Pathology}, volume = {59}, year = {2010}, month = {August 2010}, pages = {604{\textendash}612}, abstract = {

Field observations, isolations and pathogenicity tests were performed on Austrocedrus chilensis (Cupressaceae) trees to determine the pathogenicity of Phytophthora austrocedrae and its role in the aetiology of the cypress disease mal del cipr{\'e}s (MDC) in Argentina. It was found that P. austrocedrae is a primary pathogen of A. chilensis. It was isolated from large necrotic lesions in the inner bark, and superficially in the sapwood, at the root collar and stem, in most of the MDC-affected stands surveyed along the range of A. chilensis in Argentina. The main symptom in naturally infected trees was a necrotic lesion extending from killed roots up to 1\ m up the tree bole. Seedlings, saplings and adult trees were all susceptible to inoculation with P. austrocedrae. Under favourable experimental conditions (flooding), inoculated seedlings suffered massive mortality in less than a month. The importance of diseases caused by Phytophthora spp. in South American forests is discussed.

}, keywords = {cypress, forest pathology, root rot, soilborne pathogens}, doi = {10.1111/j.1365-3059.2010.02258.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2010.02258.x}, author = {Greslebin, A. G. and Hansen, E.M.} } @article {Greslebin2007308, title = {Phytophthora austrocedrae sp. nov., a new species associated with Austrocedrus chilensis mortality in Patagonia (Argentina)}, journal = {Mycological Research}, volume = {111}, number = {3}, year = {2007}, pages = {308 - 316}, abstract = {

Phytophthora austrocedrae is a new species isolated from necrotic lesions of stem and roots of Austrocedrus chilensis. It is a homothallic species characterized by semipapillate sporangia, oogonia with amphigynous antheridia, and very slow growth (1-2{\textdagger}mm{\textdagger}d-1 on V-8 agar at 17.5{\textdagger}${\i}nfty$C optimum temperature). Phylogenetic analysis of ITS rDNA sequence indicates that its closest relative is Phytophthora syringae, another species frequently isolated from soil and streams in A. chilensis forests.

}, keywords = {soil pathogens}, issn = {0953-7562}, doi = {DOI: 10.1016/j.mycres.2007.01.008}, url = {http://www.sciencedirect.com/science/article/B7XMR-4MWPSTC-2/2/cd293441766ba86e83832d81ab837e1a}, author = {Greslebin, Alina G. and Hansen, Everett M. and Sutton, Wendy} } @article {4022, title = {Phytophthora multivora causing leaf spot on rhododendrons in Argentina}, journal = {New Disease Reports}, volume = {27}, year = {2013}, month = {06/2013}, pages = {20}, abstract = {

Rhododendron is a genus belonging to the family Ericaceae and contains over 1000 species commonly known as rhododendrons and azaleas (Dimitri, 1978). Phytophthora multivora is a species that was described in Western Australia in 2008 but before that it was misidentified as . citricola (Scott et al., 2009). During the early spring of 2011, leaf spot symptoms were observed on rhododendrons in two gardens in Tigre (northern Buenos Aires province) and in containers in a nursery near Buenos Aires city. Leaf spots were dark brown to almost black, visible on both sides near the leaf tips and margins, while tissue death continued down the leaf along the midrib (Fig. 1A). The veins under the diseased area of the leaves presented a reddish tint (Fig. 1B). Some leaves became brown and died, while in others the infection remained as spots on leaves.

A Phytophthora species was consistently isolated from symptom-bearing leaf tissues on PARBH medium (Jeffers \& Martin, 1986). Hyphal tips reaching the surface of the medium were transferred onto potato dextrose agar (PDA) without inhibitors for purification and identification. Sporangia were produced abundantly in non-sterile soil extract. The majority of them were semi-papillate and ovoid, limoniform, ellipsoid or obpyriform (Fig. 2). Sporangia with two papillae were occasionally formed (Scott et al., 2009). Chlamydospores were not observed. Isolates were homothallic with plerotic oospores, 22.9 {\textpm} 1.9 μm and paragynous antheridia (Fig. 3). The optimum growth temperature was 25 {\textpm} 1{\textdegree}C on V8A (Scott et al., 2009) and the maximum growth temperature was 32 {\textpm} 1{\textdegree}C. The ITS was amplified and sequenced (GenBank Accession No. JQ812127) and showed that it was identical to P. multivora, ex-type CBS 124.094 (FJ237517) by BLAST analysis (Altschul et al., 1997). The isolate (ARod 110) was deposited in the culture collection of the Phytopathology Chair of the Faculty of Agronomy of Buenos Aires (FAUBA).

Due to the difficulty of performing pathogenicity tests in the field, detached leaves of Rhododendron spp., Camellia sp. Viburnum tinus and Photinia fraseri were inoculated in the laboratory with the ARod 110 isolate. The tests were performed by inoculating five detached leaves with a 5 mm mycelium plug taken from a seven-day-old PDA culture. Controls were inoculated with PDA discs. Leaves were incubated at 20-22{\textordmasculine}C under 12h light/12h dark cycle. All the inoculated leaves, except Camellia sp., developed necrotic lesions seven days after inoculation. . multivora was re-isolated from infected tissue. Symptoms were not detected on the controls. These characteristics conformed to those of Phytophthora multivora Scott \& Jung. To our knowledge, this is the first record of P. multivora causing leaf spot on Rhododendron in Argentina and in Latin America, and it may be a potential pathogen for Viburnum tinus and Photinia fraseri.

}, doi = {10.5197/j.2044-0588.2013.02710.5197/j.2044-0588.2013.027.020}, url = {http://www.ndrs.org.uk/article.php?id=027020}, author = {Grijalba, P.E. and Palmucci, H.E. and Guillin, E. and Herrera, C.} } @article {MPP:MPP500, title = {Phytophthora ramorum: a pathogen with a remarkably wide host range causing sudden oak death on oaks and ramorum blight on woody ornamentals}, journal = {Molecular Plant Pathology}, volume = {9}, number = {6}, year = {2008}, pages = {729{\textendash}740}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum is an oomycete plant pathogen classified in the kingdom Stramenopila. P.\ ramorum is the causal agent of sudden oak death on coast live oak and tanoak as well as ramorum blight on woody ornamental and forest understorey plants. It causes stem cankers on trees, and leaf blight or stem dieback on ornamentals and understorey forest species. This pathogen is managed in the USA and Europe by eradication where feasible, by containment elsewhere and by quarantine in many parts of the world. Genomic resources provide information on genes of interest to disease management and have improved tremendously since sequencing the genome in 2004. This review provides a current overview of the pathogenicity, population genetics, evolution and genomics of P.\ ramorum. Taxonomy: Phytophthora ramorum (Werres, De Cock \& Man in{\textquoteright}t Veld): kingdom Stramenopila; phylum Oomycota; class Peronosporomycetidae; order Pythiales; family Pythiaceae; genus Phytophthora.Host range: The host range is very large and the list of known hosts continues to expand at the time of writing. Coast live oak and tanoak are ecologically, economically and culturally important forest hosts in the USA. Rhododendron, Viburnum, Pieris, Syringa and Camellia are key ornamental hosts on which P.\ ramorum has been found repeatedly, some of which have been involved in moving the pathogen via nursery shipments. Disease symptoms: P.\ ramorum causes two different diseases with differing symptoms: sudden oak death (bleeding lesions, stem cankers) on oaks and ramorum blight (twig dieback and/or foliar lesions) on tree and woody ornamental hosts.Useful websites: http://nature.berkeley.edu/comtf/, http://rapra.csl.gov.uk/, http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/index.shtml, http://genome.jgi-psf.org/Phyra1_1/Phyra1_1.home.html, http://pamgo.vbi.vt.edu/, http://pmgn.vbi.vt.edu/, http://vmd.vbi.vt.edu./, http://web.science.oregonstate.edu/bpp/labs/grunwald/resources.htm, http://www.defra.gov.uk/planth/pramorum.htm, http://www.invasive.org/browse/subject.cfm?sub=4603, http://www.forestry.gov.uk/forestry/WCAS-4Z5JLL

}, issn = {1364-3703}, doi = {10.1111/j.1364-3703.2008.00500.x}, url = {http://dx.doi.org/10.1111/j.1364-3703.2008.00500.x}, author = {Gr{\"u}nwald, Niklaus J. and Goss, Erica M. and Press, Caroline M.} } @article {doi:10.1094/PDIS-08-10-0609, title = {Phytophthora-ID.org: a sequence-based Phytophthora identification tool}, journal = {Plant Disease}, volume = {95}, number = {3}, year = {2011}, pages = {337-342}, doi = {10.1094/PDIS-08-10-0609}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-08-10-0609}, author = {Gr{\"u}nwald, Niklaus J. and Martin, Frank N. and Larsen, Meredith M. and Sullivan, Christopher M. and Press, Caroline M. and Michael D. Coffey and Hansen, Everett M. and Parke, Jennifer L.} } @article {PPA:PPA2538, title = {Phytophthora obscura sp. nov., a new species of the novel Phytophthora subclade 8d}, journal = {Plant Pathology}, volume = {61}, year = {2012}, month = {June 2012}, pages = {610{\textendash}622}, publisher = {Blackwell Publishing Ltd}, abstract = {

A new Phytophthora species was detected (i) in the USA, infecting foliage of Kalmia latifolia, (ii) in substrate underneath Pieris, and (iii) in Germany in soil samples underneath Aesculus hippocastanum showing disease symptoms. The new species Phytophthora obscura sp. nov. is formally named based on phylogenetic analysis, host range, Koch{\textquoteright}s postulates and morphology. Phytophthora obscura is homothallic with paragynous antheridia and semipapillate sporangia. It is genetically closely related to P.\ syringae and P.\ austrocedrae and together these three species define a new Phytophthora subclade 8d, with significant support for all genetic loci analysed including seven nuclear genes and the mitochondrial gene coxII. The morphological and ecological characteristics are very similar to P.\ syringae, and it is likely that P.\ obscura was not described earlier because it was identified as P.\ syringae. Artificial inoculations indicated that horse chestnut, kalmia, pieris and rhododendron might be hosts, and Koch{\textquoteright}s postulates were confirmed for kalmia from which it was isolated. This pathogen was named after its elusive nature since it has to date rarely been detected in the US and Germany.

}, keywords = {Aesculus hippocastanum, Kalmia latifolia, oomycete, Pieris, Rhododendron, taxonomy}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2011.02538.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2011.02538.x}, author = {N. J. Gr{\"u}nwald and Werres, S. and Goss, E. M. and Taylor, C. R. and Fieland, V. J.} } @article {EFP:EFP167, title = {Pathogenicity of Phytophthora species to Pacific Northwest conifers}, journal = {European Journal of Forest Pathology}, volume = {12}, number = {3}, year = {1982}, pages = {167{\textendash}174}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora root rot is described for the first time killing sugar pine (Pinus lambertiana) in a seed orchard and four species of true fir (Abies spp.) in a forest nursery. P. cactorum was recovered from true firs and P. megasperma was recovered from sugar pine. P. cryptogea was recovered from sugar pine and true fir but isolates from the two locations differed from each other in pathogenicity and colony appearance. Isolates recovered from these hosts and isolates of 6 Phytophthora species previously recovered from Douglas-fir (Pseudotsuga menziesii) were then tested for pathogenicity on seedlings of 9 Northwest conifers. P. megasperma Group 1, P. cryptogea, and P. cinnamomi were pathogenic to all tree species except western redcedar (Thujaplicata). Western hemlock (Tsuga heterophylla) and true firs were susceptible to most species tested; ponderosa (P. ponderosa) and sugar pines were damaged only by P. cryptogea and P. cinnamomi; western redcedar was resistant to all isolates.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.1982.tb01390.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.1982.tb01390.x}, author = {P.B. Hamm and Hansen, E.M.} } @article {654, title = {Phytophthora pseudotsugae, a new species causing root rot of Douglas-fir}, journal = {Can. J. Bot.}, volume = {61}, year = {1983}, pages = {2626{\textendash}2631}, abstract = {

Phytophthora pseudotsugae n. sp. was isolated from rotted roots of Douglas-fir growing in forest tree nurseries in Oregon and Washington. It is distinguished by large oogonia and oospores, mostly paragynous antheridia, and predominantly spherical or ovoid, persistent sporangia borne primarily on simple and unbranched sporangiophores. Sporangia are formed occasionally in liquid culture, rarely in solid media. Phytophthora pseudotsugae is distinguished most readily from P. cactorum by its unbranched sporangiophores and persistent sporangia. It also differs in growth on defined media, electrophoretic protein patterns, and pathogenicity. Comparison is also made with P. iranica, the other species in group 1 of Waterhouse.

}, doi = {10.1139/b83-289}, url = {http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=eng\&journal=cjb\&volume=61\&year=1983\&issue=10\&msno=b83-289}, author = {P.B. Hamm and Hansen, E.M.} } @article {EverettM.Hansen01012009, title = {Phytophthora rosacearum and P. sansomeana, new species segregated from the Phytophthora megasperma "complex"}, journal = {Mycologia}, volume = {101}, number = {1}, year = {2009}, pages = {129-135}, abstract = {

Phytophthora megasperma sensu lato was a conglomeration of morphologically similar but phylogenetically unrelated species. In this paper we continue the segregation of species from the old P. megasperma complex, formally naming two previously recognized isolate groups. Isolates recovered from rosaceous fruit trees (especially apple and cherry) are in ITS clade 6, related to but distinct from P. megasperma sensu strictu. They are named here Phytophthora rosacearum. They have been referred to previously as the "AC" or "high temperature small oospore" group of P. megasperma. A second group of isolates, earlier called "soybean race non-classifiable", recovered from soybeans in Indiana and other Midwestern states, are morphologically similar to P. megasperma sensu strictu but unrelated to that species, falling in ITS clade 8. They are named here P. sansomeana. Isolates recovered from Douglas-fir seedlings in nurseries in the Pacific Northwest and various weedy hosts in New York State, referred to in earlier work as "P. megasperma DF1", appear to be conspecific with the soybean isolates, although they include certain ITS DNA polymorphisms. Both new species are supported by a combination of new and previously published morphological, growth and molecular data.

}, doi = {10.3852/07-203}, url = {http://www.mycologia.org/cgi/content/abstract/101/1/129}, author = {Hansen, Everett M. and Wilcox, Wayne F. and Reeser, Paul W. and Sutton, Wendy} } @article {3992, title = {Phytophthora beyond agriculture}, journal = {Annual Review of Phytopathology}, volume = {50}, year = {2012}, month = {09/2012}, pages = {359 - 378}, abstract = {

Little is known about indigenous Phytophthora species in natural ecosystems. Increasing evidence, however, suggests that a diverse, trophically complex Phytophthora community is important in many forests. The number of described species has steadily increased, with a dramatic spike in recent years as new species have been split from old and new species have been discovered through exploration of new habitats. Forest soil, streams, and the upper canopies of trees are now being explored for Phytophthora diversity, and a new appreciation for the ecological amplitude of the genus is emerging. Ten to twenty species are regularly identified in temperate forest surveys. Half or more of this Phytophthora diversity comes from species described since 2000. Taxa in internal transcribed spacer (ITS) Clade 6 are especially numerous in forest streams and may be saprophytic in this habitat. Three ecological assemblages of forest Phytophthora species are hypothesized: aquatic opportunists, foliar pathogens, and soilborne fine-root and canker pathogens. Aggressive invasive species are associated with all three groups.

}, issn = {0066-4286}, doi = {10.1146/annurev-phyto-081211-172946}, url = {http://www.annualreviews.org/doi/pdf/10.1146/annurev-phyto-081211-172946}, author = {Hansen, Everett M. and Reeser, Paul W. and Sutton, Wendy} } @article { refId, title = {Phytophthora species in oak forests of north-east France}, journal = {Ann. For. Sci.}, volume = {56}, number = {7}, year = {1999}, pages = {539-547}, abstract = {

Phytophthora species were surveyed from the end of 1997 through July 1998 in oak forests in NE France. Healthy (Amance) or declining (Illwald) forests were compared. The Phytophthora population in both was diverse and locally abundant. At least eight species were present at Amance and six at Illwald. At Amance Phytophthora species had a localized distribution in water and low-lying soils. At Illwald distribution was more uniform apparently due to flooding events. Most often recovered were P. citricola, P. gonapodyides and P. quercina. P. gonapodyides was ubiquitous in water and colonized leaf debris. P. quercina was widely distributed in soil but not abundant, and was found in sites that did not otherwise appear to favor Phytophthora. No correlation was detected between presence of Phytophthora in soil and health of trees. Unusual combinations of environmental factors may be required for resident Phytophthora to have a detrimental impact on oaks. {\textcopyright} 1999 Editions scientifiques et m{\'e}dicales Elsevier SAS.

}, doi = {10.1051/forest:19990702}, url = {http://dx.doi.org/10.1051/forest:19990702}, author = {Hansen, E.M. and Delatour, Claude} } @article {360, title = {Phytophthora nemorosa, a new species causing cankers and leaf blight of forest trees in California and Oregon, U.S.A.}, journal = {Mycotaxon}, volume = {88}, year = {2003}, pages = {129{\textendash}138}, abstract = {

Phytophthora nemorosa, a new species isolated from stem cankers on two species of Fagaceae and leaves of various hosts, is described. The new species resembles P. ilicis with homothallic, amphigynous antheridia and deciduous, semi-papillate sporangia, and has a related ITS-DNA sequence. Symptoms and host range are similar to P. ramorum, cause of Sudden Oak Death and leaf blight and shoot dieback diseases in California and Oregon forests, although P. nemorosa does not appear to cause wide-spread mortality of oak trees.

}, keywords = {Lithocarpus densiflorus, Phytophthora ilicis, Phytophthora ramorum, Quercus agrifolia, Umbellularia californica}, url = {http://www.mycotaxon.com/vol/abstracts/88/88-129.html}, author = {Hansen, E.M. and P. Reeser and J. M. Davidson and Garbelotto, M. and K. Ivors and L. Douhan and D. M. Rizzo} } @article {4654, title = {Phytophthora species in oak forests of north-east France}, journal = {ANNALS OF FOREST SCIENCE}, volume = {56}, year = {1999}, month = {Jan-01-1999}, pages = {539 - 547}, abstract = {

Phytophthora species were surveyed from the end of 1997 through July 1998 in oak forests in NE France. Healthy (Amance) or declining (Illwald) forests were compared. The Phytophthora population in both was diverse and locally abundant. At least eight species were present at Amance and six at Illwald. At Amance Phytophthora species had a localized distribution in water and low-lying soils. At Illwald distribution was more uniform apparently due to flooding events. Most often recovered were P. citricola, P. gonapodyides and P. quercina. P. gonapodyides was ubiquitous in water and colonized leaf debris. P. quercina was widely distributed in soil but not abundant, and was found in sites that did not otherwise appear to favor Phytophthora. No correlation was detected between presence of Phytophthora in soil and health of trees. Unusual combinations of environmental factors may be required for resident Phytophthora to have a detrimental impact on oaks. {\textcopyright} 1999 Editions scientifiques et m{\'e}dicales Elsevier SAS.

}, issn = {0003-4312}, doi = {10.1051/forest:19990702}, url = {http://www.afs-journal.org/10.1051/forest:19990702}, author = {Hansen, Everett and Delatour, Claude} } @inbook {4177, title = {Phytophthora omnivora (Phytophthora fagi und Peronospora sempervivi)}, booktitle = {Lehrbuch der Baumkrankheiten}, year = {1882}, pages = {42-46}, publisher = {Verlag von Julius Springer}, organization = {Verlag von Julius Springer}, address = {Berlin}, author = {Hartig, R.} } @article {ho2002phytophthora, title = {Phytophthora cinnamomi var. robiniae var. nova on black locust in jiangsu province of China}, journal = {Mycotaxon}, volume = {82}, year = {2002}, pages = {391{\textendash}396}, publisher = {Mycotaxon}, issn = {0093-4666}, author = {Ho, HH} } @article {ChuanxueHong03012011, title = {Phytophthora pini Leonian resurrected to distinct species status}, journal = {Mycologia}, volume = {103}, number = {2}, year = {2011}, pages = {351-360}, abstract = {

Phytophthora pini was named by Leonian in 1925, but this species was largely ignored until 1956 and then merged with P. citricola by Waterhouse in 1963. This study compared the ex-type and ex-authentic cultures of these two species with isolates of P. plurivora and the P. citricola subgroups Cil I and III reported previously. Examination of these isolates revealed that the ex-type culture of P. pini is identical to P. citricola I. Phytophthora pini Leonian therefore is resurrected to distinct species status and redescribed here with a Latin description, replacing P. citricola I. Molecular, physiological and morphological descriptions of this species are presented. The molecular description includes DNA sequences of five nuclear and mitochondrial regions as well as PCR-SSCP fingerprints. The relationship among the above species and other species recently segregated from the P. citricola complex also is discussed.

}, doi = {10.3852/10-058}, url = {http://www.mycologia.org/cgi/content/abstract/103/2/351}, author = {Hong, Chuanxue and Gallegly, Mannon E. and Richardson, Patricia A. and Kong, Ping} } @article {4456, title = {Phosphorus acid for controlling Phytophthora {\textquoteleft}taxon Agathis{\textquoteright} in kauri: glasshouse trials. }, journal = {New Zealand Plant Protection}, volume = {66}, year = {2013}, pages = {242-248}, abstract = {

Phytophthora taxon Agathis (PTA) is a serious problem in Auckland and Northland kauri forests. Phosphorous acid (phosphite) is a potential treatment for infected or threatened trees. In vitro tests on phosphite-amended agar showed that PTA was more sensitive to phosphite than other Phytophthora species commonly controlled by this chemical. Before progressing to forest trials, phosphite efficacy was tested on PTA-inoculated kauri seedlings in the glasshouse. Two-year-old kauri seedlings were inoculated with PTA applied directly to trunk wounds or by soil application. Phosphite was applied as a foliar spray, as a trunk injection or as a soil drench either 5 days before or 5 days after inoculation. All untreated control trees died, whether trunk- or soil-inoculated. With phosphite injection, survival was 100\% following PTA soil inoculation and 67\% following trunk inoculation. Foliar spray and soil drench-applied phosphite treatments were less effective than trunk injection, although some trees survived.

}, issn = {1175-9003 (print), 1179-352X (online)},}, url = {http://www.nzpps.org/nzpp_abstract.php?paper=662420}, author = {Horner, I.J. and Hough, E.G.} } @article {EFP:EFP715, title = {Phytophthora ramorum is a generalist plant pathogen with differences in virulence between isolates from infectious and dead-end hosts}, journal = {Forest Pathology}, volume = {42}, number = {1}, year = {2012}, pages = {8{\textendash}13}, publisher = {Blackwell Publishing Ltd}, abstract = {

Variation in virulence was examined among isolates of Phytophthora ramorum from epidemiologically important or infectious (non-oak) and transmissive dead-end (oak) hosts from North America. Twelve isolates representative of the genetic, geographic and host range of P.\ ramorum in the western United States were inoculated on leaves of Umbellularia californica (bay laurel or bay) and stems of Quercus agrifolia (coast live oak). In spite of extreme genetic similarity among the isolates employed, and even within the same genotype, significant differences in lesion size were measured, suggesting virulence in this pathogen is also controlled by epigenetic factors. A strong positive correlation between lesion size on bay laurel and coast live oak provides experimental evidence P.\ ramorum is a generalist pathogen that lacks host specificity. Isolates from non-transmissive oaks were significantly less pathogenic both on oaks and bays than isolates from infectious hosts. These results are essential to further our understanding of the epidemiology and evolutionary potential of this pathogen. A quantitative differential in virulence of isolates from hosts with different epidemiological roles has been described for many animal diseases, but is a novel report for a plant disease.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00715.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00715.x}, author = {H{\"u}berli, D. and Garbelotto, M.} } @article {PPA:PPA2513, title = {Potential susceptibility of Australian native plant species to branch dieback and bole canker diseases caused by Phytophthora ramorum}, journal = {Plant Pathology}, volume = {61}, number = {2}, year = {2012}, pages = {234{\textendash}246}, publisher = {Blackwell Publishing Ltd}, abstract = {

Susceptibility to branch dieback caused by Phytophthora ramorum was tested using a detached branch assay for 66 Australian native plant species sourced from established gardens and arboreta in California. Six of these species were further tested for their susceptibility to bole cankers caused by P.\ ramorum using a sealed log assay. Isopogon formosus and Eucalyptus denticulata were identified as potentially highly susceptible Australian branch dieback hosts. Thirteen potentially tolerant Australian host species included Banksia attenuata, B.\ marginata, E. haemastoma, E.\ regnans, Pittosporum undulatum and Billardiera heterophylla. Eucalyptus regnans was identified as a potentially highly susceptible bole canker host, while E.\ diversicolor and E.\ viminalis were considered potentially tolerant species to bole cankers caused by P.\ ramorum. Phytophthora ramorum was able to infect all 66 species, as confirmed by reisolation. These results extend the known potential host range for P.\ ramorum, confirm it as a possible threat to Australian plant industries and ecosystems and highlight additional associated hosts that are important in the global horticultural trade, native forests and plantation forestry.

}, keywords = {invasive organism, oomycete, ramorum branch dieback, Sudden oak death}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2011.02513.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2011.02513.x}, author = {Ireland, K. B. and H{\"u}berli, D. and Dell, B. and Smith, I. W. and D. M. Rizzo and Hardy, G. E. St. J.} } @article {EFP:EFP755, title = {Potential susceptibility of Australian flora to a NA2 isolate of Phytophthora ramorum and pathogen sporulation potential}, journal = {Forest Pathology}, volume = {42}, year = {2011}, pages = {305{\textendash}320}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum is an invasive plant pathogen and the cause of considerable and widespread damage in nurseries, gardens and natural woodland ecosystems of the USA and Europe. It is considered to be a significant plant disease as it could cause biodiversity loss and severe economic losses in plant industries in areas where it is not yet known to exist, such as Australasia. Foliar susceptibility and sporulation potential were tested using detached-leaf assays for 70 Australian native plant species sourced from established gardens and arboreta in California using a NA2 isolate of P. ramorum. Correa {\textquoteright}Sister Dawn{\textquoteright}, Eucalyptus regnans, Isopogon cuneatus, I. formosus, Leptospermum scoparium, L. lanigerum and Melaleuca squamea were identified as potentially highly susceptible host species. Hedycarya angustifolia, Olearia argophylla, Phyllocladus aspleniifolius, Pittosporum undulatum and Podocarpus lawrencei were identified as potentially resistant. All 70 species were able to be infected with P. ramorum, as confirmed by reisolation. Putative sporulating hosts include five members of the Myrtaceae, Agonis flexuosa, Corymbia ficifolia, Eucalyptus haemastoma, E. delegatensis and E. viminalis. As a part of a precautionary strategy, the potentially highly susceptible species found in this study are suitable candidates for targeted surveillance programmes in high-risk incursion areas of Australia and within the global horticultural trade.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00755.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00755.x}, author = {Ireland, K. B. and H{\"u}berli, D. and Dell, B. and Smith, I. W. and D. M. Rizzo and Hardy, G. E. St. J.} } @article {4694, title = {Potential host range of four Phytophthora interspecific hybrids from Clade 8a}, journal = {Plant Pathology}, volume = {69}, year = {2020}, month = {May-11-2020}, pages = {1281 - 1290}, abstract = {

In recent years several interspecific hybrids have been reported in the plant pathogenic oomycete genus Phytophthora. Due to the large genotypic and phenotypic changes, these hybrids might have broader or more limited host ranges compared with their parental species. It is crucial to understand the host range of Phytophthora hybrids to minimize the economic losses caused by their infection. The potential host range of four hybrids belonging to Clade 8a of the Phytophthora phylogenetic tree was investigated in this study. Thirty species of herbaceous plants as well as eight species of woody plants were inoculated and monitored for any symptom of infection. In addition, the detached twigs of 32 tree species, fruits of six plant species, tubers of potato, and roots of carrot and sugar beet were investigated for susceptibility to these hybrids. Almost all hybrids caused severe rot on all tested fruits, tubers, and roots, although different isolates showed different pathogenicity on detached tree twigs. All hybrids tested had a different host range compared with their parental species: they were able to infect plants outside the host range of their parents, infect hosts of both parental species, although these parents did not have overlapping hosts, or, in some cases, they were not able to infect hosts infected by the parents.

}, issn = {0032-0862}, doi = {10.1111/ppa.v69.710.1111/ppa.13205}, url = {https://bsppjournals.onlinelibrary.wiley.com/doi/abs/10.1111/ppa.13205}, author = {Jafari, Fatemeh and Mostowfizadeh-Ghalamfarsa, Reza and Safaiefarahani, Banafsheh and Burgess, Treena I.} } @article {3972, title = {Pathogenicity of Swedish isolates of Phytophthora quercina to Quercus robur in two different soils}, journal = {New Phytologist}, volume = {158}, year = {2003}, month = {05/2003}, pages = {355 - 364}, abstract = {
}, issn = {0028-646X}, doi = {10.1046/j.1469-8137.2003.00734.x}, author = {J{\"o}nsson, Ulrika and Thomas Jung and Rosengren, Ulrika and Nihlg{\r a}rd, Bengt and Sonesson, Kerstin} } @article {3967, title = {Phytophthora gallica sp. nov., a new species from rhizosphere soil of declining oak and reed stands in France and Germany}, journal = {Mycological Research}, volume = {112}, year = {2008}, month = {10/2008}, pages = {1195 - 1205}, abstract = {

A non-papillate, slow-growing Phytophthora species, which could not be assigned to any existing taxon, was isolated from rhizosphere soil of a declining oak in Northeast France, and from the rhizosphere of Phragmites australis at Lake Constance in south-west Germany in 1998 and 2004, respectively. We describe this species, previously informally designated Phytophthora taxon {\textquoteleft}G{\textquoteright}, as Phytophthora gallica sp. nov. Morphology, growth rates, and pathogenicity against cuttings of riparian tree species and leaves of reed are described and compared with those of morphologically and phylogenetically similar Phytophthora species. P. gallica produces colonies with limited aerial mycelium and variable growth patterns. Gametangia are not formed in single or mixed cultures with tester strains of known mating types. P. gallica produces globose and elongated irregular chlamydospores, of which a high proportion is abortive. In water culture irregular hyphal swellings and non-papillate persistent sporangia are formed abundantly. P. gallica is moderately aggressive to Alnus glutinosa and Fagus sylvatica, weakly aggressive to Quercus robur and Salix alba and non-pathogenic to Fraxinus excelsior and Phragmites australis. According to ITS and mtDNA sequence data P. gallica belongs to a distinct Phytophthora clade, with P. boehmeriae and P. kernoviae being the closest relatives. The origin of P. gallica and its ecological role in wet ecosystems remain unclear.

}, issn = {09537562}, doi = {10.1016/j.mycres.2008.04.007}, author = {Thomas Jung and Nechwatal, Jan} } @article {1294133220040401, title = {Phytophthora root and collar rot of alders in Bavaria: distribution, modes of spread and possible management strategies.}, journal = {Plant Pathology}, volume = {53}, number = {2}, year = {2004}, pages = {197 - 208}, abstract = {

A survey of symptoms of phytophthora root and collar rot of common (Alnus glutinosa) and grey alder (A. incana) in riparian and forest stands in Bavaria was conducted by the Bavarian State Forestry and river authorities. Symptoms were seen in 1041 out of 3247 forest alder stands. The majority of the affected stands (80{\textperiodcentered}9\%) were less than 21 years old; 46\% of these young stands were growing on nonflooded sites and 92\% had been planted. The riparian survey showed that symptoms were widespread along more than 50\% of the river systems. Along some rivers the disease incidence exceeded 50\%. The {\textquoteleft}alder Phytophthora{\textquoteright} was recovered from 166 of 185 riparian and forest alder stands with symptoms. In 58 of the 60 rivers and streams investigated in detail, the source of inoculum was traced back to infested young alder plantations growing on the river banks or on forest sites that drain into the rivers. Once introduced to a river system, the {\textquoteleft}alder Phytophthora{\textquoteright} infects alders downstream. Baiting tests showed that the {\textquoteleft}alder Phytophthora{\textquoteright} was present in rootstocks of alders from three out of four nurseries which regularly bought in alder plants for re-sale, but not in rootstocks from four nurseries that grew their own alders from seed. In addition, the infected nurseries used water from infested water courses for irrigation. The Bavarian State Ministry for Agriculture and Forestry has developed a code of practice for producing healthy alder plants in forest nurseries. This includes a 3-year fallow period between bare-rooted alder crops because of poor survival of the {\textquoteleft}alder Phytophthora{\textquoteright} in soil.

}, keywords = {ALDER {\textendash} Diseases \& pests, Alnus, Bavaria, diseases, fungal diseases of plants, GERMANY, nursery, pathway, Phytophthora, plantation, riparian areas}, issn = {00320862}, doi = {10.1111/j.0032-0862.2004.00957.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.0032-0862.2004.00957.x/abstract}, author = {T. Jung and Blaschke, M.} } @article {3976, title = {Phytophthora quercina sp. nov., causing root rot of European oaks}, journal = {Mycological Research}, volume = {103}, year = {1999}, month = {7/1999}, pages = {785 - 798}, abstract = {

In a 3 year study of oak (Quercus robur, Q. petraea, Q. cerris, Q. pubescens and Q. ilex) decline in Central and Southern Europe, a papillate homothallic Phytophthora species was isolated consistently, with other Phytophthora spp., from necrotic fine roots by direct plating on to selective agar medium and from rhizosphere soil samples by baiting with leaves of Quercus robur. The morphology, physiology, RAPD banding patterns and pathogenicity against apple fruits of this Phytophthora sp. are described and compared with those of other papillate Phytophthora species from Waterhouse{\textquoteright}s Group I, namely P. cactorum, P. clandestina, P. idaei, P. iranica, P. pseudotsugae and P. tentaculata, and papillate Group III P. citricola. The papillate Phytophthora isolates from oak differed from all other Group I species by their uniform, dome-shaped and cottonwool-like colony growth pattern on V8 juice agar and malt extract agar, the frequent occurrence of sympodially branched primary hyphae, a high proportion of elongated, ellipsoid or ovoid oogonia, the absence of amphigynous antheridia and RAPD banding patterns. Additionally, there was no other species in Group I with as much variation in size and shape of the sporangia or large proportion of sporangia with a curved apex, hyphal projections, lateral displacement of the papilla and lateral attachment to the sporangiophore. In pathogenicity tests with infested soil, the isolates proved to be more pathogenic to Q. robur than any other Phytophthora sp. recovered from declining oaks in Central Europe. Based on their unique combination of cultural, sporangial and gametangial morphology, pathogenicity and close association with Quercus but not other trees, the papillate Phytophthora isolates from oak are described as Phytophthora quercina sp. nov.

}, issn = {09537562}, doi = {10.1017/S0953756298007734}, url = {http://www.sciencedirect.com/science/article/pii/S0953756208606115}, author = {T. Jung and Cooke, D. E. L. and Blaschke, H. and Duncan, J. M. and W. O{\ss}wald} } @article {4656, title = {Phytophthora root and collar rot of alders in Bavaria: distribution, modes of spread and possible management strategies}, journal = {Plant Pathology}, volume = {53}, year = {2004}, month = {Jan-04-2004}, pages = {197 - 208}, abstract = {

A survey of symptoms of phytophthora root and collar rot of common (Alnus glutinosa) and grey alder (A. incana) in riparian and forest stands in Bavaria was conducted by the Bavarian State Forestry and river authorities. Symptoms were seen in 1041 out of 3247 forest alder stands. The majority of the affected stands (80{\textperiodcentered}9\%) were less than 21\ years old; 46\% of these young stands were growing on nonflooded sites and 92\% had been planted. The riparian survey showed that symptoms were widespread along more than 50\% of the river systems. Along some rivers the disease incidence exceeded 50\%. The {\textquoteleft}alder Phytophthora{\textquoteright} was recovered from 166 of 185 riparian and forest alder stands with symptoms. In 58 of the 60 rivers and streams investigated in detail, the source of inoculum was traced back to infested young alder plantations growing on the river banks or on forest sites that drain into the rivers. Once introduced to a river system, the {\textquoteleft}alder Phytophthora{\textquoteright} infects alders downstream. Baiting tests showed that the {\textquoteleft}alder Phytophthora{\textquoteright} was present in rootstocks of alders from three out of four nurseries which regularly bought in alder plants for re-sale, but not in rootstocks from four nurseries that grew their own alders from seed. In addition, the infected nurseries used water from infested water courses for irrigation. The Bavarian State Ministry for Agriculture and Forestry has developed a code of practice for producing healthy alder plants in forest nurseries. This includes a 3-year fallow period between bare-rooted alder crops because of poor survival of the {\textquoteleft}alder Phytophthora{\textquoteright} in soil.

}, issn = {0032-0862}, doi = {10.1111/j.0032-0862.2004.00957.x}, url = {http://doi.wiley.com/10.1111/j.0032-0862.2004.00957.x}, author = {Jung, T. and Blaschke, M.} } @article {3970, title = {Phytophthora pseudosyringae sp. nov., a new species causing root and collar rot of deciduous tree species in Europe}, journal = {Mycological Research}, volume = {107}, year = {2003}, month = {7/2003}, pages = {772 - 789}, abstract = {

In several studies of oak decline in Europe, a semi-papillate homothallic Phytophthora taxon was consistently isolated, together with other Phytophthora species, from rhizosphere soil samples. It was also found associated with necrotic fine roots and stem necroses of Fagus sylvatica and Alnus glutinosa. Due to morphological and physiological similarities, the semi-papillate isolates were previously identified as P. syringae by various authors. The morphology, physiology and pathogenicity against fine roots of Quercus robur, Q. petraea and F. sylvatica, bark of A. glutinosa, leaves of Ilex aquifolium and apple fruits of this Phytophthora species are described and compared with those of related and similar Phytophthora species, namely P. ilicis, P. psychrophila, P. quercina, P. citricola and P. syringae. The phylogenetic placement on the basis of ITS and mtDNA sequence data was also examined. Isolates of this taxon produce colonies with stellate to rosaceous growth patterns and limited aerial mycelium on various agar media. Antheridia are predominantly paragynous. In water culture catenulate hyphal swellings and semi-papillate caducous sporangia, that are usually limoniform, ellipsoid or ovoid, are formed abundandly, mostly in lax or dense sympodia. This taxon is a moderately slow growing, low temperature species with optimum and maximum temperatures around 20 and 25 {\textdegree}C, respectively. Tested isolates are moderately aggressive to fine roots of oaks and beech, highly aggressive to holly leaves and apple fruits, and slightly pathogenic to alder bark. Thirteen tested isolates had an identical and distinct ITS sequence which was more similar to that of P. ilicis and P. psychrophila than any other known taxa. On the basis of their unique combination of morphological characters, colony growth patterns, cardinal temperatures for growth, growth rates, pathogenicity to oaks, beech, alder, apple and holly, their host range, and ITS and mtDNA sequences the semi-papillate caducous Phytophthora isolates from oaks, beech and alder are clearly separated from related and similar Phytophthora spp., and described as a new species, P. pseudosyringae sp. nov.

}, issn = {09537562}, doi = {10.1017/S0953756203008074}, author = {Thomas Jung and Nechwatal, Jan and David E.L. Cooke and Hartmann, {\"u}nther and Blaschke, Markus and O{\ss}wald, Wolfgang F. and James M. Duncan and Delatour, Claude} } @article {4468, title = {Phytophthora {\texttimes}alni and Phytophthora lacustris associated with common alder decline in Central Portugal}, journal = {Forest Pathology}, volume = {46}, year = {2016}, month = {Jan-04-2016}, pages = {174 - 176}, abstract = {

Since the early 1990s, an emerging disease induced by the highly aggressive oomycete Phytophthora {\texttimes}alni has caused widespread alder decline across Europe. In parallel, P.\ lacustris, a recently described species associated with riparian habitats, has been subject of increasing interest. A field survey conducted in 2014 showed high mortality rates in alder stands located in the riparian gallery along two rivers in Central Portugal. The pathogens isolated from necrotic alder stem base during this study were identified as P.\ {\texttimes}alni and P.\ lacustris. This paper is the first to report the occurrence of P.\ lacustris in Portugal and presents the first finding of P.\ {\texttimes}alni affecting mature trees in natural ecosystems located in Central Portugal.

}, doi = {10.1111/efp.2016.46.issue-210.1111/efp.12273}, url = {http://doi.wiley.com/10.1111/efp.2016.46.issue-2http://doi.wiley.com/10.1111/efp.12273}, author = {Kanoun-Boul{\'e}, M. and Vasconcelos, T. and Gaspar, J. and Vieira, S. and Dias-Ferreira, C. and Husson, C.}, editor = {Woodward, S.} } @article {10.1371/journal.pone.0034728, title = {Phenotypic diversification Is associated with host-induced transposon derepression in the sudden oak death pathogen Phytophthora ramorum}, journal = {PLoS ONE}, volume = {7}, number = {4}, year = {2012}, month = {04/2012}, pages = {e34728}, publisher = {Public Library of Science}, abstract = {

The oomycete pathogen Phytophthora ramorum is responsible for sudden oak death (SOD) in California coastal forests. P. ramorum is a generalist pathogen with over 100 known host species. Three or four closely related genotypes of P. ramorum (from a single lineage) were originally introduced in California forests and the pathogen reproduces clonally. Because of this the genetic diversity of P. ramorum is extremely low in Californian forests. However, P. ramorum shows diverse phenotypic variation in colony morphology, colony senescence, and virulence. In this study, we show that phenotypic variation among isolates is associated with the host species from which the microbe was originally cultured. Microarray global mRNA profiling detected derepression of transposable elements (TEs) and down-regulation of crinkler effector homologs (CRNs) in the majority of isolates originating from coast live oak (Quercus agrifolia), but this expression pattern was not observed in isolates from California bay laurel (Umbellularia californica). In some instances, oak and bay laurel isolates originating from the same geographic location had identical genotypes based on multilocus simples sequence repeat (SSR) marker analysis but had different phenotypes. Expression levels of the two marker genes analyzed by quantitative reverse transcription PCR were correlated with originating host species, but not with multilocus genotypes. Because oak is a nontransmissive dead-end host for P. ramorum, our observations are congruent with an epi-transposon hypothesis; that is, physiological stress is triggered on P. ramorum while colonizing oak stems and disrupts epigenetic silencing of TEs. This then results in TE reactivation and possibly genome diversification without significant epidemiological consequences. We propose the P. ramorum-oak host system in California forests as an ad hoc model for epi-transposon mediated diversification.

}, doi = {10.1371/journal.pone.0034728}, url = {http://dx.doi.org/10.1371\%2Fjournal.pone.0034728}, author = {Kasuga, , Takao and Kozanitas, , Melina and Bui, , Mai and H{\"u}berli, , Daniel and Rizzo, David M. and Garbelotto, Matteo} } @article {kliejunas_phytophthora_1981, title = {Phytophthora root rot of Port-Orford-cedar in California.}, journal = {Plant disease}, volume = {65}, number = {5}, year = {1981}, pages = {446{\textendash}447}, abstract = {

Phytophthora Root Rot of {Port-Orford-Cedar} in California. John T. Kliejunas, Plant Pathologist, Forest Pest Management, Forest Service, {U.S.} Department of Agriculture, San Francisco, {CA} 94111. David H. Adams, Forest Pathologist, Department of Forestry, State of California, Sacramento 95814. Plant Dis. 65:446-447. . This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. {DOI:} {10.1094/PD-65-446.} The {Port-Orford-cedar} stands on federal, state, and private lands in northern California were surveyed in the spring of 1980 for Phytophthora root rot caused by Phytophthora lateralis. The disease was present at six sites on the Gasquet Ranger District, Six Rivers National Forest, and Jedediah Smith Redwoods State Park, Del Norte County, and on six ornamental cedars at a residence in Eureka, Humboldt County.

}, keywords = {California, Chamaecyparis lawsoniana}, issn = {01912917}, author = {J.T. Kliejunas and D.H. Adams} } @article {kliejunas1979phytophthora, title = {Phytophthora cinnamomi in Hawaiian forest soils: seasonal variations in population levels}, journal = {Phytopathology}, volume = {69}, year = {1979}, pages = {1268{\textendash}1272}, abstract = {

Soils from three ohia forest sites with trees showing varying degrees of decline, and from adjacent healthy and declining sites, were sampled biweekly for population levels of Phytophthora cinnamomi over an 8- to 13-mo period. Population levels varied considerably among sites and within the same site throughout the course of the study. At the three sites, the fungus generally was undetectable or its population levels were lowest in the winter months when minimum soil temperatures were near 10 C and then they increased as soil temperatures increased. Population levels decreased after extended periods of heavy rain and measurements at six of the eight monthly sampling times were significantly higher at the decline site than at the adjacent healthy site. Significant correlations between P. cinnamomi population levels and maximum soil temperature, minimum soil temperature, and rainfall were found at some sites but not at others. Soil matric potentials at all sites ranged from 0 to {\textendash}30 mb and were seldom less than {\textendash}25 mb. High water holding capacity of the soils combined with rainfall averages ranging 2,984{\textendash}3,489 mm/yr apparently were favorable for sporangium formation. Zoospores were prevalent at certain times of the year.

}, doi = {10.1094/Phyto-69-1268}, url = {http://www.apsnet.org/publications/phytopathology/backissues/Documents/1979Abstracts/Phyto69_1268.htm}, author = {J.T. Kliejunas and Nagata, JT} } @article {4723, title = {Preventing Phytophthora infestations in restoration nurseries: a key to protecting wildland plant communities.}, journal = {Oregon State University Extension Service}, year = {2022}, url = { https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9330.pdf}, author = {Kline, N. and Elliott, M. and Parke, J. and Stark, D. and Shaw, D. and Christiansen, A.} } @article {ko2006possible, title = {The possible origin and relation of Phytophthora katsurae and P. heveae, discovered in a protected natural forest in Taiwan}, journal = {Botanical Studies}, volume = {47}, number = {3}, year = {2006}, pages = {273{\textendash}277}, author = {Ko, W. H. and Wang, SY and Ann, PJ} } @article {1979, title = {Phytophthora katsurae, a new name for P. castaneae}, journal = {Mycologia}, volume = {71}, number = {4}, year = {1979}, pages = {pp. 840-844}, publisher = {Mycological Society of America}, abstract = {

P. katsurae is proposed to replace P. castaneae Katsura \& Uchida from chestnut [RPP 57, 2024] which is illegitimate, being a later homonym of P. castaneae (Mangin) Clements \& Shear.

}, issn = {00275514}, url = {http://www.jstor.org/stable/3759198}, author = {Ko, W. H. and Chang, H. S.} } @article {4446, title = {Potential of Ypt1 and ITS gene regions for the detection of Phytophthora species in a lab-on-a-chip DNA hybridization array}, journal = {Plant Pathology}, volume = {64}, year = {2015}, month = {Jan-10-2015}, pages = {1176 - 1189}, abstract = {

A novel DNA-chip hybridization assay that uses the ras-related GTP-binding protein 1 gene (Ypt1) was developed for the identification of several devastating Phytophthora species. The hybridization was conducted in a portable microfluidic lab-on-a-chip device for fast and accurate detection of 40 Phytophthora, two Pythium and one Phytopythium species. Moreover, the functionality of the Ypt1 region was examined in comparison to an array for the internal transcribed spacer (ITS) region by in silico modelling. The difference in species-specific capture probe sequences was lower for the ITS than for the Ypt1 region. While ITS-probes of Phytophthora ramorum, Phytophthora fragariae and Phytophthora lateralis cross-reacted with up to 11 non-target species, Ypt1-probes were specific except for P.\ fragariae/Phytophthora rubi. First analyses of artificially inoculated Rhododendron leaves successfully demonstrated the usability of the respective capture probes for the Ypt1 and the ras-related plant protein Rab1a gene region. The on-chip hybridization enabled the detection of up to 1\ pg\ μL-1 target DNA depending on the species examined. Due to the complementarity of ITS and Ypt1 genetic features, the use of multiple loci is recommended to identify targets of different taxonomic rank.

}, doi = {10.1111/ppa.2015.64.issue-510.1111/ppa.12357}, url = {http://doi.wiley.com/10.1111/ppa.2015.64.issue-5http://doi.wiley.com/10.1111/ppa.12357http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fppa.12357}, author = {K{\"o}nig, S. and Schwenkbier, L. and Pollok, S. and Riedel, M. and Wagner, S. and Popp, J. and Weber, K. and Werres, S.} } @article {4379, title = {Phytophthora tentaculata sp. nov. und Phytophthora cinnamomi var. parvispora var. nov., zwei neue Pilze von Zierpflanzen in Deutschland}, journal = {Journal of Plant Diseases and Protection }, volume = {100}, year = {1993}, pages = {250-258}, abstract = {

W{\"a}hrend der letzten beiden Jahre sind in Deutschland in einigen stark gesch{\"a}digten Gew{\"a}chshausbest{\"a}nden von Zierpflanzen wiederholt zwei Vertreter der Gattung Phytophthora isoliert worden, die bisher noch nicht bekannt waren. Sie werden hier als P. tentaculata und als P. cinnamomi vai. parvispora beschrieben.

From severely damaged ornamental plants found in greenhouses in Germany, two representatives of the genus Phytophthora were isolated. Because these fungi are unknown until now they are described in this treatise as new fungi, namely P. tentaculata and P. cinnamomi var. parvispora.

}, url = {http://www.jstor.org/stable/43386173}, author = {Krober, K and Marwitz, RZ} } @article {kroeber1993phytophthora, title = {Phytophthora tentaculata sp. nov. and Phytophthora cinnamomi var. parvispora var. nov., two new fungi from ornamental plants in Germany}, journal = {Zeitschrift fuer Pflanzenkrankheiten und Pflanzenschutz (Germany)}, volume = {v. 100(3)}, year = {1993}, pages = {p. 250-258}, issn = {0340-8159}, author = {Kroeber, H. and Marwitz, R.} } @article {4252, title = {Phylogenetic analysis of Phytophthora species based on mitochondrial and nuclear DNA sequences}, journal = {Fungal Genetics and Biology}, volume = {41}, year = {2004}, month = {Jan-08-2004}, pages = {766 - 782}, abstract = {

A molecular phylogenetic analysis of the genus Phytophthora was performed, 113 isolates from 48 Phytophthora species were included in this analysis. Phylogenetic analyses were performed on regions of mitochondrial (cytochrome c oxidase subunit 1; NADH dehydrogenase subunit 1) and nuclear gene sequences (translation elongation factor 1α; β-tubulin) and comparisons made to test for incongruence between the mitochondrial and nuclear data sets. The genus Phytophthora was confirmed to be monophyletic. In addition, results confirm that the classical taxonomic grouping as described by [Waterhouse (1963)] does not reflect true phylogenetic relations. Phytophthora species were redistributed into 8 clades, providing a more accurate representation of phylogenetic relationships within the genus Phytophthora. The evolution and transition of morphological, pathogenic, and reproductive traits was inferred from the cladogram generated in this study. Mating system was inferred to be a homoplasious trait, with at least eight independent transitions from homothallism to heterothallism observed.

}, issn = {10871845}, doi = {10.1016/j.fgb.2004.03.007}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1087184504000611}, author = {Kroon, L.P.N.M and Bakker, F.T and van den Bosch, G.B.M and Bonants, P.J.M and Flier, W.G} } @article {4634, title = {Phytophthora chlamydospora and P. megasperma associated with root and crown rot of sour cherry in Turkey}, journal = {Journal of Plant Diseases and Protection}, volume = {124}, year = {2017}, month = {Jan-08-2017}, pages = {403 - 406}, abstract = {

Sour cherry is a very important commercial crop of Turkey. In a newly established orchard in Ankara province of Turkey, some of young sour cherry trees did not leaf out or collapsed after a while turning green in spring, 2014. Lateral and hairy roots of symptomatic trees showed poor growth. Occurrence of necrotic and decay tissues girdling the whole roots resulted in tree mortality. Two Phytophthora spp. were isolated from necrotic tissues on taproots and crowns. The pathogens were identified as Phytophthora chlamydospora and P. megasperma based on morphological characteristics and DNA sequences of the internal transcribed spacer region. Pathogenicity of the isolates was tested by stem inoculation to sour cherry seedlings. P. chlamydospora caused canker lesions and killed the seedlings within 4\ weeks, while no cankers occurred on stem of the plants inoculated with P. megasperma and on control plants. Also P. megasperma was found as pathogen on roots of sour cherry seedlings in soil infestation test. This is the first report of P. chlamydospora and P. megasperma causing crown and root rot of sour cherry in Turkey. In addition, P. chlamydospora is a new pathogen of sour cherry grafted on Prunus mahaleb.

}, issn = {1861-3829}, doi = {10.1007/s41348-017-0075-y}, url = {http://link.springer.com/content/pdf/10.1007/s41348-017-0075-y.pdf}, author = {Kurbetli, {\.I}lker and Aydo{\u g}du, Mehmet and S{\"u}l{\"u}, G{\"o}rkem} } @article {4295, title = {Phytophthora on Betula spp. (birch)}, journal = {JKI Data Sheets {\textendash} Plant Diseases and Diagnosis}, volume = {80}, year = {2013}, pages = {7 pp}, abstract = {

Birch is an important forest tree especially in colder climates. It is monoecious and wind polli- nated species, and it has wind-dispersed seeds. The genus contains more than 60 taxa including trees and shrubs. B. pendula Roth (silver birch) and B pubescens Ehrh. (downy birch) have both wide distribution in Europe and are also found in northern parts of Asia (Hämet-Ahti et al., 1989, Niemistö et al., 2008). B. alleghaniensis Britton (yellow birch), B. lenta L. (sweet birch), B. papyrifera Marshall (paper birch) B. populifolia Marsh. (grey birch) and B. nigra L. (river birch) are species typical for North America (Hämet-Ahti et al., 1989; Verkasalo, 1990). In Scandinavia and northern Europe B. pendula is an important tree species for forest industry, but also used as amenity trees in parks, alleys and in gardens. B. alleghaniensis, B. lenta and B. papyrifera are also valuable for forest industry. Birches are cold tolerant pioneer species and in southern Europe they are found mainly on higher altitudes. Many Betula species such as B. nana L. (dwarf birch), B. pubescens subsp. czerepanovii (Orlova) Hämet-Ahti (arctic moor birch) and B. utilis D. Don (Himalayan birch) are typi- cal for treeline. B. nana and it{\textquoteright}s subspecies are shrubs native to arctic and cool temperate regions of northern Europe, northern Asia and northern North America. They are also present in Greenland as well as in mountains in Scotland and the Alps. B. utilis is growing as a shrub or tree native to the the Himalayas (Hämet-Ahti et al., 1989; http://www.discoverlife.org).

}, issn = {2191-1398}, doi = {10.5073/jkidspdd.2013.080}, url = {http://www.jki.bund.de/fileadmin/dam_uploads/_veroeff/JKI_Datenblaetter/Phytophthora/englisch/final_Betula_en.pdf}, author = {Lilja, Arja and Thinggaard, K. and Munda, Alenka} } @article {PPA:PPA627, title = {Phytophthora katsurae from cocoa}, journal = {Plant Pathology}, volume = {38}, number = {4}, year = {1989}, pages = {627{\textendash}629}, publisher = {Blackwell Publishing Ltd}, abstract = {Phytophthora katsurae is reported for the first time from cocoa.}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.1989.tb01463.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.1989.tb01463.x}, author = {Liyanage, NIS and Wheeler, BEJ} } @article {martin_phylogenetic_2003, title = {Phylogenetic relationships of Phytophthora ramorum, P. nemorosa, and P. pseudosyringae, three species recovered from areas in California with sudden oak death.}, journal = {Mycological research}, volume = {107}, year = {2003}, pages = {1379{\textendash}1391}, keywords = {California, cytochrome-c oxidase, forest trees, fungal anatomy, internal transcribed spacers, mitochondrial DNA, molecular systematics, phylogeny, Phytophthora, Phytophthora ramorum, plant pathogenic fungi, Quercus, ribosomal DNA, sequence analysis}, issn = {09537562}, doi = {http://dx.doi.org/10.1017/S0953756203008785}, author = {F.N. Martin and P.W. Tooley} } @article {4198, title = {Phytophthora cinnamomi as a Contributor to White Oak Decline in Mid-Atlantic United States Forests}, journal = {Plant Disease}, volume = {98}, year = {2014}, month = {Jan-03-2014}, pages = {319 - 327}, abstract = {

To evaluate Phytophthora cinnamomi as a cause of white oak (Quercus alba) decline in mid-Atlantic forests, sampling was conducted at 102 sites from 2011 to 2012. Soil and roots from healthy and declining white oak trees were collected. Phytophthora spp. were isolated using baiting and CFU of P. cinnamomi quantified using wet-sieving. Fine roots were scanned and measured. Phytophthora spp. were isolated from 43\% of the sites. P. cinnamomi was common; six other species were isolated infrequently. Little difference in lesion size existed on white oak seedlings inoculated with 32 isolates of P. cinnamomi; only 13 isolates caused significant mortality. Soils from white oak versus nine other hosts did not have significantly different CFU. P. cinnamomi was restricted to United States Department of Agriculture hardiness zones six and seven and never found in zone five. The presence of Phytophthora spp. in soil can be associated with white oak fine root health. When Phytophthora spp. were present, white oak trees in zones five and six had less fine roots. In mid-Atlantic oak forests, however, environmental conditions appear to play a key role in determining the impact of P. cinnamomi on the root system. P. cinnamomi alone does not appear to be a causal factor of white oak decline.

}, issn = {0191-2917}, doi = {10.1094/PDIS-06-13-0649-RE}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-06-13-0649-RE}, author = {McConnell, M. E. and Balci, Y.} } @mastersthesis {mcwilliams_port-orford-cedar_2000, title = {Port-Orford-cedar and Phytophthora lateralis: grafting and heritability of resistance in the host, and variation in the pathogen}, volume = {PhD}, year = {2000}, school = {Oregon State University}, type = {masters}, address = {Corvallis}, abstract = {

Port-Orford-cedar (Chamaecyparis lawsoniana) is a forest tree native to a small area of Oregon and California. A root disease caused by Phytophthora lateralis causes widespread mortality of Port-Orford-cedar. This dissertation examines three important elements of the Port-Orford-cedar P. lateralis pathosystem related to breeding for disease resistance: use of resistant rootstocks to maintain genotypes of Port-Orford-cedar for breeding; the heritability and genetic basis of disease resistance; and variability in virulence and DNA fingerprint among a sample of P. lateralis isolates. Port-Orford-cedar was reciprocally grafted to western redcedar (Thuja plicata), incense cedar (Calocedrus decurrens), and Alaska yellow-cedar (Chamaecyparis nootkatensis). Port-Orford-cedar scion graft success was moderate with western red cedar and incense cedar, but extreme overgrowth of the rootstock by the scion indicated incompatibility. Xylem union was good, but phloem union was incomplete or lacking. Nearly all Port-Orford-cedar rootstocks and seedlings exposed to P. lateralis died of root disease. Four percent of the Alaska yellow-cedar exposed also died, confirming this tree as a host for P. lateralis. Resistance of Port-Orford-cedar to P. lateralis is rare. A small number of trees have been identified exhibiting resistance. A number of families were tested to determine the genetic basis for resistance. Estimates of narrow-sense and family mean heritability of resistance, as exhibited by restriction of lesion length after inoculation, were determined. Both narrow-sense and family mean heritabilities were between 0.61 and 0.98 in most tests. Between 21\% and 32\% of the variance was due to differences among families. Thirteen isolates of P. lateralis were collected from three hosts throughout the geographic range of the fungus. Variation in growth rate on artificial media at three temperatures, virulence when used to inoculate Port-Orford-cedar, and DNA fingerprint were compared. There were significant differences in growth rate among isolates at 24C, but fewer differences at lower temperatures and on a rich medium. One isolate produced significantly shorter lesions in three different inoculation tests. Isolates differed at only two of 189 bands produced by Inter Simple Sequence Repeat (ISSR) DNA primers, indicating very little genetic variation among isolates.

}, url = {http://oasis.oregonstate.edu/record=b2155969}, author = {Michael G McWilliams} } @mastersthesis {4516, title = {Produtividade e sustentabilidade de planta{\c c}{\~o}es de ac{\'a}cia-negra (Acacia mearnsii De Wild.) no Rio Grande do Sul. Curitiba}, volume = {Doctoral}, year = {2007}, month = {03/2007}, pages = {266}, school = {Universidade Federal do Paran{\'a}}, address = {Curitiba, Brazil}, abstract = {

This work aimed to evaluate the factors related to the productivity, sustainability and environmental impacts of the black wattle plantation in Rio Grande do Sul, Brazil. The studies made about those plantations analyzed the utilization of the genetically improved seeds, the soil attributes influence, the P and K fertilization profit, the uptake, cycling and exportation of nutrients, the biomass production and partition, the black wattle invasion in the grassland area and riparian forest, the forest succession and the understorey herbaceous vegetation of the black wattle plantation. The timber production at the age of five years increased in 9.1 m3/ha through the seed improvement adoption that represented a net profit of R$ 180.00 per ha; however those increments depended on the utilization of suitable silvicultural practices. The gummosis (Phytophthora sp.) was observed in 33.9\% of the dead trees during the period from three to five years and reduced in 9.0\% the growth of attacked plants. The optimal economic rotation defined by the net present worth, considering an infinite horizon, was at the age of four years for the land owner and at the age of six years for the renters. The P, K and organic matter on the soil had positive effects on the black wattle growth. Similarly, it was found the response to the P and K fertilization, with a medium increase of 36.2\% in the timber volume, and the P also promoted the greatest increments and the response to the K were great on the optimal dose of the P. The greatest foliage efficiency for the biomass production and the maximum timber productivity occurred at the age of five years. At the age of seven years the trunk represented around 80\% of the aboveground biomass and stored a greater quantity of P,K, Ca and Mg. The N and S accumulation was greater in the crown trees compartments. The nutrients cycling rate via litter during de rotation of seven years varied from 25.3 to 59.6\% and after the age of four years they represented more then 60\% of the nutrients absorbed by the plants. The Ca and K were the nutrients exported in a greater quantity by the forest harvest. The best efficiency of the nutrients to the trunk biomass production and the least nutrients exportation per biomass unit harvested occurred when the plantations were six and seven years old. The black wattle was able to invade only disturbed grassland area with total exposure of the soil, for this reason it must be considered as a causal invasive plant. The native vegetation recomposition of those areas provoked mortality of a greater number of invasive plants. In the other hand, the black wattle does not become an invasive plant in the riparian forest and when planted in those areas proportioned an abundant and diversified succession in its understorey. The black wattle plantation in grassland area reduced part of the floristic diversity of the herbaceous vegetation and propitiated the typical species settlement in the understorey forests, however they did not affected the site environmental resilience.

}, url = {http://www.floresta.ufpr.br/pos-graduacao/defesas/pdf_dr/2007/t218_0266-D.pdf}, author = {Mochiutti, S.} } @article {385, title = {Phytophthora alni (Brasier et al.) update on alder Phytophthora and potential new hosts}, journal = {NAPPO Phytosanitary Alert}, number = {04/05/2006}, year = {2006}, publisher = {North American Plant Protection Organization, NSF Center for Integrated Pest Management}, edition = {04/05/2006}, url = {http://www.pestalert.org/viewNewsAlert.cfm?naid=15}, author = {NAPPO} } @article {4443, title = {Pathogenicity to alder of Phytophthora species from riparian ecosystems in western Oregon}, journal = {Forest Pathology}, volume = {45}, year = {2015}, month = {Jan-10-2015}, pages = {358 - 366}, abstract = {

Described as one of the most destructive pathogens of agricultural crops and forest trees, Phytophthora is a genus of microorganisms containing over 100 known species. Phytophthora alni has caused collar and root disease in alders throughout Europe, and a subspecies has recently been isolated in North America. Reports of canopy dieback in red alder, Alnus rubra, prompted a survey of their overall health and to determine whether P.\ alni was present in western Oregon riparian ecosystems. Over 1100 Phytophthora isolates were recovered, representing 20 species and 2 taxa. Phytophthora-type cankers were observed in many trees, and their incidence was positively correlated with canopy dieback. High levels of mortality for red alder were not observed, which suggests these Phytophthora species are not aggressive pathogens. To test this hypothesis, three stem wound inoculations and one root dip were conducted on red alder seedlings using 13 Phytophthora species recovered from the riparian survey. Ten of the 13 Phytophthora species produced significant lesions in at least one pathogenicity test. Phytophthora siskiyouensis produced the largest lesions on red alder from the two stem wound inoculation tests conducted under summer conditions, while P.\ taxon Pgchlamydo caused the largest lesions during the winter stem wound inoculation test. Phytophthora gonapodyides, P.\ taxon Pgchlamydo and P.\ siskiyouensis have previously been found associated with necrotic alder roots and bole cankers in the field, and with the pathogenicity results reported here, we have established these species as causes of Phytophthora root disease and Phytophthora bole canker of alder in Oregon. While none of the Phytophthora species were especially aggressive towards red alder in the pathogenicity tests, they did cause localized disease symptoms. By weakening the root systems or boles of alders, the Phytophthoras could be leaving alders more susceptible to other insects and pathogens.

}, doi = {10.1111/efp.2015.45.issue-510.1111/efp.12175}, url = {http://doi.wiley.com/10.1111/efp.2015.45.issue-5http://doi.wiley.com/10.1111/efp.12175http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fefp.12175}, author = {Navarro, S. and Sims, L. and Hansen, E. and Vannini, {\'A}.} } @article {nelson2010prevalence, title = {Prevalence, distribution and identification of Phytophthora species from bleeding canker on European beech}, journal = {Phytopathology}, volume = {28}, number = {3}, year = {2010}, pages = {150{\textendash}158}, author = {Nelson, A. and Weiland, G. and Hudler, G.} } @article {PPA:PPA2476, title = {Potential for eradication of the exotic plant pathogens Phytophthora kernoviae and Phytophthora ramorum during composting}, journal = {Plant Pathology}, volume = {60}, number = {6}, year = {2011}, pages = {1077{\textendash}1085}, publisher = {Blackwell Publishing Ltd}, abstract = {

Temperature and exposure time effects on Phytophthora kernoviae and Phytophthora ramorum viability were examined in flasks of compost and in a large-scale composting system containing plant waste. Cellophane, rhododendron leaf and peat-based inoculum of P. kernoviae and P. ramorum isolates were used in flasks; naturally infected leaves were inserted into a large-scale system. Exposures of 5 and 10 days respectively at a mean temperature of 35{\textdegree}C in flask and large-scale composts reduced P. kernoviae and P. ramorum inocula to below detection limits using semi-selective culturing. Although P. ramorum was undetectable after a 1-day exposure of inoculum to compost at 40{\textdegree}C in flasks, it survived on leaves exposed to a mean temperature of 40{\textperiodcentered}9{\textdegree}C for 5 days in a large-scale composting system. No survival of P. ramorum was detected after exposure of infected leaves for 5 days to a mean temperature of \>=41{\textperiodcentered}9{\textdegree}C (32{\textperiodcentered}8{\textdegree}C for P. kernoviae) or for 10 days at \>=31{\textperiodcentered}8{\textdegree}C (25{\textperiodcentered}9{\textdegree}C for Phytophthora pseudosyringae on infected bilberry stems) in large-scale systems. Fitted survival probabilities of P. ramorum on infected leaves exposed in a large-scale system for 5 days at 45{\textdegree}C or for 10 days at 35{\textdegree}C were \<3\%, for an average initial infection level of leaves of 59{\textperiodcentered}2\%. RNA quantification to measure viability was shown to be unreliable in environments that favour RNA preservation: high levels of ITS1 RNA were recovered from P. kernoviae- and P. ramorum-infected leaves exposed to composting plant wastes at \>53{\textdegree}C, when all culture results were negative.

}, keywords = {Phytophthora pseudosyringae, Rhododendron ponticum, temperature, Vaccinium myrtillus}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2011.02476.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2011.02476.x}, author = {Noble, R. and Blackburn, J. and Thorp, G. and Dobrovin-Pennington, A. and Pietravalle, S. and Kerins, G. and Allnutt, T. R. and Henry, C. M.} } @article {oh_port-orford-cedar_2006, title = {Port-Orford-cedar resistant to Phytophthora lateralis.}, journal = {Forest pathology }, volume = {36}, number = {6}, year = {2006}, pages = {385{\textendash}394}, issn = {14374781}, doi = {10.1111/j.1439-0329.2006.00474.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0329.2006.00474.x/full}, author = {E. Oh and R. A. Sniezko and Hansen, E.M.} } @article {EFP:EFP714, title = {Phytophthora root and collar rot of mature Fraxinus excelsior in forest stands in Poland and Denmark}, journal = {Forest Pathology}, volume = {41}, number = {6}, year = {2011}, pages = {510{\textendash}519}, publisher = {Blackwell Publishing Ltd}, abstract = {

In recent years, Common ash (Fraxinus excelsior) throughout Europe has been severely impacted by a leaf and twig dieback caused by the hyphomycete Chalara fraxinea. The reasons for its current devastating outbreak, however, still remain unclear. Here, we report the presence of four Phytophthora taxa in declining ash stands in Poland and Denmark. Phytophthora cactorum, Phytophthora plurivora, Phytophthora taxon salixsoil and Phytophthora gonapodyides were isolated from rhizosphere soil samples and necrotic bark lesions on stems and roots of mature declining ash trees in four stands. The first three species proved to be aggressive to abscised roots, twigs and leaves of F. excelsior in inoculation experiments. Soil infestation tests also confirmed their pathogenicity towards fine and feeder roots of ash seedlings. Our results provide first evidence for an involvement of Phytophthora species as a contributing factor in current decline phenomena of F. excelsior across Europe. Specifically, they may act as a predisposing factor for trees subsequently infected by C. fraxinea. Phytophthora species from ash stands also proved to be aggressive towards a wide range of tree and shrub species commonly associated with F. excelsior in mixed stands. Although damage varied considerably depending on the Phytophthora species/isolate-host plant combination, these results show that many woody species may be a potential source for survival and inoculum build-up of soilborne Phytophthora spp. in ash stands and forest ecosystems in general.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00714.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00714.x}, author = {Orlikowski, L.B. and Ptaszek, M. and Rodziewicz, A. and Nechwatal, J. and Thinggaard, K. and T. Jung} } @article {doi:10.1094/PHYTO-97-12-1558, title = {Phytophthora ramorum colonizes tanoak xylem and is associated with reduced stem water transport}, journal = {Phytopathology}, volume = {97}, number = {12}, year = {2007}, pages = {1558-1567}, doi = {10.1094/PHYTO-97-12-1558}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-97-12-1558}, author = {Parke, J. L. and E. Oh and Voelker, S. and Hansen, E.M. and Buckles, G. and Lachenbruch, B.} } @proceedings {958, title = {The Phytophthora online course: Training for nursery growers}, volume = {Gen. Tech. Rep. PSW-GTR-229}, year = {2010}, pages = {355}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station}, address = {Santa Cruz, California}, url = {http://www.fs.fed.us/psw/publications/documents/psw_gtr229/}, author = {Parke, J. L. and J. Pscheidt and R. Regan and Hedberg, J. and N. J. Gr{\"u}nwald}, editor = {Frankel, S.J. and J.T. Kliejunas and K. M. Palmieri} } @article {4361, title = {Phytophthora castaneae, the correct name for P. katsurae nom. nov. superfl.}, journal = {Mycotaxon}, volume = {121}, year = {2013}, month = {Sep-01-2013}, pages = {327 - 331}, abstract = {

Phytophthora katsurae was proposed as a nom. nov. for P. castaneaeon the assumption that the replaced name was an illegitimate later homonym. This assumption was based on the invalid nomen nudum publication of {\textquotedblleft}Phytophthora castaneae{\textquotedblright} in a host{\textendash}pathogen index as a synonym of Mycelophagus castaneae, and an erroneous interpretation of Clements \& Shear{\textquoteright}s listing of the type of the genus Mycelophagus. There is no valid earlier homonym. Phytophthora castaneae is the correct legitimate name for the taxon causing trunk rot of Castanea crenata, and P. katsurae is an illegitimate superfluous name.

}, issn = {2154-8889}, doi = {10.5248/121.327}, url = {http://dx.doi.org/10.5248/121.327}, author = {Pennycook, Shaun R.} } @article {4311, title = {Phytophthora siskiyouensis causing stem lesions and cankers on Alnus incana}, journal = {New Disease Reports}, volume = {31}, year = {2015}, month = {Jun-06-2017}, pages = {17}, abstract = {

In late summer 2013, stem cankers and sparse foliage were reported on European grey alder (Alnus incana) growing on a 500 ha site recently-planted with broadleaf and coniferous trees in south-west England. A site visit showed that approximately 10\% of\  more than 1000 grey alders (thought to have been imported from Europe and planted in the late 1990s) had symptoms including bleeding stem lesions similar to those caused by Phytophthora alni (Gibbs et al., 2003). In November 2013, samples were collected from stem lesions (Fig. 1), roots (internal lesions tracking-down from stem lesions) and rhizosphere soil from symptom-bearing trees. Tissue from root and stem lesion margins was plated onto Phytophthora selective medium (SMA) (amended as per Brasier et al., 2005) and incubated at 20{\textdegree}C for 48 hrs. Green apples were used as baits for soil samples by inserting a few grams of soil under a flap cut in the side of the apple and incubating for 4-7 days at 20{\textdegree}C. Isolation from developing SMA mycelial cultures and incubated apple baits onto potato dextrose agar (PDA) and carrot agar (CA) was then undertaken.

After 14 days on PDA at 20{\textdegree}C in the dark, colonies exhibited a distinctive stellate growth pattern (Fig. 2a). On CA they had a diffuse {\textquoteright}frosty{\textquoteright} appearance (Fig. 2b). On CA, oogonia with predominantly paragynous antheridia and aplerotic oospores were abundant. Partially-caducous sporangia formed when plugs from colonies on CA were submerged in unsterile pond water held at 20{\textdegree}C in the dark. Sporangia (46-51 μm wide) were semi-papillate and were ovoid, reniform, elongated or irregular in shape (Fig. 3). Sporangial morphology and dimensions corresponded to Phytophthora siskiyouensis (Reeser et al., 2007) and sequences of ITS and coxII regions supported this identification (GenBank Accession Nos. KP207601 and KP207602).\ 

One isolate of P. siskiyouensis was obtained from each of three different symptomatic trees; one from a root lesion, one from a stem lesion and one from associated soil. Koch{\textquoteright}s postulates were tested by inoculating two-year-old potted A. incana saplings with the three isolates. A small wound was made on the stem 10 cm above soil level. A CA plug colonised by P. siskiyouensis was inserted and the wound was sealed with Parafilm. Nine saplings were inoculated per isolate and maintained at 20{\textdegree}C with a 12-hr-photoperiod. Three control saplings were inoculated with sterile CA plugs. After 20 days, cankers and bleeding were visible externally on all of the trees inoculated with P. siskiyouensis (Fig. 4). The bark was peeled away to reveal phloem lesions extending approximately 2-4 cm above and below the inoculation point. No lesions developed on control trees. After re-isolation onto SMA, a Phytophthora sp. was recovered from all of the inoculated trees but not from the controls and it was identified as P. siskiyouensis by morphology (Reeser et al., 2007) and sequencing of the ITS region.

Phytophthora siskiyouensis is a recently-described species in the USA, isolated from stem lesions on myrtlewood (Umbellularia californica) and tanoak (Lithocarpus densiflorus; synonym of Nothocarpus densiflorus) and from soil and stream water, in south-west Oregon (Reeser et al., 2007). It has also been reported causing stem lesions on Italian alder (Alnus cordata) in California (Rooney-Latham et al., 2007). This is the first report of P. siskiyouensis in the UK and, to our knowledge, in Europe, and the first report of P. siskiyouensis causing stem cankers on A. incana. Its occurrence within a recently-planted site suggests a possible origin on introduced nursery stock. P. siskiyouensis has the potential to cause further damage to Alnus spp. and other plant species in Europe. Its comparative pathogenicity on various alder species is under investigation.

}, doi = {10.5197/j.2044-0588.2015.03110.5197/j.2044-0588.2015.031.017}, url = {http://www.ndrs.org.uk/contents.php?vol=31http://www.ndrs.org.uk/article.php?id=031017}, author = {P{\'e}rez-Sierra, A. and Kalantarzadeh, M. and Sancisi-Frey, S. and Brasier, C.M.} } @article {4004, title = {Previously unrecorded low-temperature Phytophthora species associated with Quercus decline in a Mediterranean forest in eastern Spain}, journal = {Forest Pathology}, volume = {43}, year = {2013}, month = {08/2013}, pages = {331{\textendash}339}, abstract = {

Oak decline has been a serious problem in Europe since the beginning of the twentieth century. In south-west Spain, Quercus ilex and Q.\ suber are the main affected species, and their decline has been associated with Phytophthora cinnamomi. During the last 10\ years, a severe decline of Q.\ ilex and Q.\ faginea accompanied by a significant decrease in the production of acorns affecting natural regeneration was observed in the eastern part of the Iberian Peninsula. Therefore, the aim of this study was to investigate the possible involvement of Phytophthora spp. in the decline. A forest in the Natural Park {\textquoteleft}Carrascar de la Font Roja{\textquoteright} in Comunidad Valenciana (eastern Spain), which is dominated by Q.\ ilex and Q.\ faginea, was surveyed during 2010{\textendash}2011. Symptomatic trees showed thinning and dieback of the crown, withering of leaves and death. An extensive loss of both lateral small woody roots and fine roots and callusing or open cankers on suberized roots were observed. Soil samples containing fine roots were baited using both Q.\ robur leaves and apple fruits. Six Phytophthora species were isolated: P.\ cryptogea, P.\ gonapodyides, P.\ megasperma, P.\ quercina, P.\ psychrophila and P.\ syringae. These are the first records of P.\ quercina and P.\ psychrophila on Q. faginea, of P.\ quercina in Spain and of P.\ psychrophila in mainland Spain. A soil infestation trial was conducted for 6\ months under controlled conditions with 1-year-old seedlings of Q.\ ilex and Q.\ faginea. Phytophthora cinnamomi was included in the pathogenicity test for comparison. The results showed that Q.\ ilex seedlings were generally more susceptible to infection than Q.\ faginea with P.\ cinnamomi being the most aggressive pathogen to both oak species. The two most commonly isolated Phytophthora species, P.\ quercina and P.\ psychrophila, also proved their pathogenicity towards both Q.\ ilex and Q.\ faginea.

}, issn = {1439-0329}, doi = {10.1111/efp.12037}, url = {http://dx.doi.org/10.1111/efp.12037}, author = {P{\'e}rez-Sierra, A. and L{\'o}pez-Garc{\'\i}a, C. and Le{\'o}n, M. and Garc{\'\i}a-Jim{\'e}nez, J. and Abad-Campos, P. and T. Jung} } @article {3995, title = {Phytophthora diversity and the population structure of Phytophthora ramorum in Swiss ornamental nurseries}, journal = {Plant Pathology}, volume = {62}, year = {2013}, month = {10/2013}, pages = {1063{\textendash}1071}, abstract = {

Invasive oomycete pathogens have been causing significant damage to native ecosystems worldwide for over a century. A recent well-known example is Phytophthora ramorum, the causal agent of sudden oak death, which emerged in the 1990s in Europe and North America. In Europe, this pathogen is mainly restricted to woody ornamentals in nurseries and public greens, while severe outbreaks in the wild have only been reported in the UK. This study presents the results of the P.\ ramorum survey conducted in Swiss nurseries between 2003 and 2011. In all 120 nurseries subjected to the plant passport system, the main P.\ ramorum hosts were visually checked for above ground infections. Phytophthora species were isolated from tissue showing symptoms and identified on the basis of the morphological features of the cultures and sequencing of the ribosomal ITS region. Phytophthora was detected on 125 plants (66 Viburnum, 58 Rhododendron and one Pieris). Phytophthora ramorum was the most frequent species (59{\textperiodcentered}2\% of the plants), followed by P.\ plurivora, P.\ cactorum, P.\ citrophthora, P.\ cinnamomi, P.\ cactorum/P.\ hedraiandra, P.\ multivora and P.\ taxon PgChlamydo. The highest incidence of P.\ ramorum was observed on Viburnum\ {\texttimes}\ bodnantense. Microsatellite genotyping showed that the Swiss P.\ ramorum population is highly clonal and consists of seven genotypes (five previously reported in Europe, two new), all belonging to the European EU1 clonal lineage. It can therefore be assumed that P.\ ramorum entered Switzerland through nursery trade. Despite sanitation measures, repeated P.\ ramorum infections have been recorded in seven nurseries, suggesting either reintroduction or unsuccessful eradication efforts.

}, doi = {10.1111/ppa.12027}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/ppa.12027}, author = {Prospero, S and Vercauteren, A. and Heungens, K. and Belbahri, L. and Rigling, D.} } @article {1312, title = {Phytophthora leaf blight - a new disease of California wax-myrtle (Morella californica) in Oregon, USA caused by a Phytophthora species}, journal = {N. Z. J. For. Sci.}, volume = {41 Suppl.}, year = {2011}, pages = {S57-S63}, abstract = {

In spring, 2009, the Oregon State University Plant Clinic received reports of severe defoliation of California wax-myrtle plants (Morella californica (Cham. \& Schlecht.) Wilbur) on the north-central coast of Oregon, in western North America. Isolations from necrotic leaf tissue yielded an organism which, from morphological characteristics and a genus-specific enzyme-linked immunosorbent assay, was identified as a species of the genus Phytophthora. Total DNA was extracted from hyphal tip-derived cultures from leaf or twig tissue and subjected to a polymerase chain reaction process aimed at species identification. Sequencing techniques revealed a 99.7\% match with P. syringae although our isolates differed from published descriptions of this species in some respects. Inoculation of healthy plants with cultured mycelium resulted in symptoms similar to those originally observed in the field, and reisolations produced colonies of the same organism. This is the first report of a species of Phytophthora causing disease in M. californica. Leaf blight of California wax-myrtle is now widespread on the north-central coast of Oregon. This disease is serious and is adversely affecting the health of this native understory species which is frequently used for amenity plantings.

}, author = {Putnam, M. L. and M. Serdani and M. Curtis and S. Angima} } @article {865, title = {Phytophthora rot of coconut.}, journal = {Oleagineux}, volume = {39}, year = {1984}, pages = {143{\textendash}147}, author = {Quillec, G and Renard, JL} } @proceedings {605, title = {Phytophthora kernoviae in New Zealand}, volume = {General Technical Report PSW-GTR-221}, year = {2009}, pages = {47-53}, publisher = {U.S. Department of Agriculture, Forest Service Pacific Southwest Research Station}, address = {Monterey, California}, abstract = {

Phytophthora kernoviae was first recognised in New Zealand in 2005 by DNA sequencing of an isolate that had been recovered from diseased Annona cherimola (cherimoya or custard apple) in an abandoned orchard in Northland in 2002. Subsequent investigation has recovered P. kernoviae from the soil in Northland, Auckland, Bay of Plenty and Taupo regions. Similarity between P. kernoviae and descriptions of an undescribed Phytophthora sp. found previously in New Zealand indicates that the organism has been present here since at least 1953. This, along with the geographic range of P. kernoviae, and a polymorphism in the ITS sequence, suggest that the pathogen has been present in New Zealand for an even longer time. Little is known of the ecological behaviour of the pathogen in New Zealand; disease has only been recorded on A. cherimola.

}, author = {Ramsfield, T.D. and Dick, M.A. and Beever, R.E. and Horner, I.J. and McAlonan, M.J. and Hill, C.F.}, editor = {Goheen, Ellen Michaels and Susan J. Frankel} } @proceedings {353, title = {Phytophthora kernoviae {\textendash} of southern hemisphere origin?}, year = {2007}, month = {August, 2007}, pages = {1 page}, address = {Monterey, Calif. Coll. of Nat. Resourc., Univ. of Calif., Berkeley.}, author = {Tod D. Ramsfield and Margaret A. Dick and Ross E. Beever and Ian J. Horner} } @article {3961, title = {Phytophthora elongata sp. nov., a novel pathogen from the Eucalyptus marginata forest of Western Australia}, journal = {Australasian Plant Pathology}, volume = {39}, year = {2010}, pages = {477-491}, abstract = {

A novel homothallic species of Phytophthora producing semipapillate sporangia on sympodially branching sporangiophores, thick-walled oospores in smooth-walled oogonia, and paragynous antheridia is described here as Phytophthora elongata sp. nov. DNA sequencing of the internal transcribed spacer (ITS) DNA and coxI gene confirm P. elongata as a distinct species within ITS clade 2. It has been isolated in the northern jarrah forest of Western Australia (WA) from the roots and collars of dead and dying Eucalyptus marginata and occasionally Corymbia calophylla in rehabilitated bauxite mine pits. It has also been associated with dead and dying plants of several mid- and understorey species in the northern and southern jarrah forest{\textemdash}Banksia grandis, Leucopogon propinquus, Dryandra squarrosa and an Andersonia sp., as well as the monocotyledonous Xanthorrhoea preissii, X. gracilis and Patersonia xanthina. P. elongata has also been isolated from sandy soils and loams in Victoria in eastern Australia. The pathogenicity of P. elongata to E. marginata and Banksia spp. has been shown in this and earlier studies. Due to the uniformity of the ITS DNA and cox 1 sequence data in WA, P. elongata may be the result of a recent clonal introduction. More pathogenicity tests on a wider range of native plant species are needed to assess the host range of P. elongata and its invasive potential in WA.

}, keywords = {biosecurity, natural ecosystems, phylogenetics}, issn = {0815-3191}, doi = {10.1071/AP10014}, url = {http://dx.doi.org/10.1071/AP10014}, author = {Rea, Alexander J. and Thomas Jung and Burgess, Treena I. and Stukely, Michael J. C. and Hardy, Giles E. St J.} } @article {PaulW. Reeser09012007, title = {Phytophthora siskiyouensis, a new species from soil, water, myrtlewood (Umbellularia californica) and tanoak (Lithocarpus densiflorus) in southwestern Oregon}, journal = {Mycologia}, volume = {99}, number = {5}, year = {2007}, pages = {639-643}, abstract = {

An unknown Phytophthora species was recovered in southwestern Oregon from rhododendron and tanoak leaf baits used for monitoring streams and soils for the presence of Phytophthora ramorum, from a blighted shoot of myrtlewood and from tanoak bark cankers. Isolates of this species yielded ITS-DNA sequences that differed substantially from other Phytophthora sequences in GenBank. Morphological features also differed from available descriptions of known Phytophthora species. Based on the combination of unique morphology and unique ITS sequences a new species is proposed. The new species, Phytophthora siskiyouensis, is homothallic with globose to subglobose oogonia, which may be terminal, sessile or laterally intercalary. Antheridia are capitate and mostly paragynous but sometimes amphigynous. Oospores are mostly aplerotic. Sporangia are variable but commonly ovoid to reniform, with apical, subapical or lateral semipapillae (occasionally more than one). Sporangia are terminal, subterminal or occasionally intercalary on unbranched sporangiophores, with basal, subbasal or lateral attachment. Sporangia are weakly deciduous, with variable length pedicels. This combination of characters clearly separates Phytophthora siskiyouensis from other known Phytophthora species.

}, doi = {10.3852/mycologia.99.5.639}, url = {http://www.mycologia.org/cgi/content/abstract/99/5/639}, author = {Reeser, Paul W. and Hansen, Everett M. and Sutton, Wendy} } @article {1318, title = {Phytophthora species causing tanoak stem cankers in southwestern Oregon}, journal = {Plant Disease}, volume = {92}, year = {2008}, month = {08/2008}, pages = {1252}, abstract = {

Tanoak (Lithocarpus densiflorus) is a principal host of Phytophthora ramorum, cause of sudden oak death (SOD), in the western United States (1). In the course of SOD surveys in southwestern Oregon, other Phytophthora species were encountered to be causing stem cankers on tanoak that were indistinguishable from those caused by P. ramorum. In Oregon, SOD is subject to quarantine and eradication. Aerial surveys are flown two or more times a year to locate symptomatic tanoaks, which are then examined from the ground to determine the cause of death. Isolations on selective media were attempted from all trees with stem cankers typical of Phytophthora. Phytophthora species were identified by morphological features and DNA sequencing of either internal transcribed spacer (ITS) or the mitochondrial COX spacer region. ITS sequences were compared with validated GenBank records, and COX spacer sequences were compared with known reference isolates in the OSU collection. From 2001 through 2006, Phytophthora spp. were isolated from 482 of 1,057 tanoak stem cankers sampled. P. ramorum was isolated from 359 cankers, P. nemorosa was isolated from 102 cankers, P. gonapodyides was isolated from six cankers, P. cambivora was isolated from four cankers (all A1 mating type), P. siskiyouensis was isolated from four cankers, P. pseudosyringae was isolated from two cankers, P. cinnamomi was isolated from one canker (mating type A2), and P. taxon {\textquotedblleft}Pgchlamydo{\textquotedblright} was isolated from one canker. Three cankers yielded isolates that were not identified but were closely related to P. pseudosyringae based on ITS sequence. No Phytophthora spp. were cultured from the remaining cankers. One isolate from each species identified (except P. ramorum and P. pseudosyringae) was tested for pathogenicity on tanoak stems (11.4 to 16.0 cm DBH) in the field. A 5-mm-diameter plug from the margin of a V8 agar culture was placed in a hole in the bark, covered with wet cheesecloth, and sealed with aluminum foil and duct tape. Each isolate was inoculated into five different stems. Each stem received three different isolates and an agar control. After 4 weeks, bark was removed to reveal lesion development. Lesions were measured (length by width), and pieces from four points on the lesion margin were plated in selective media to reisolate. P. cambivora, P. cinnamomi, P. gonapodyides, P. nemorosa, P. siskiyouensis and P. taxon {\textquotedblleft}Pgchlamydo{\textquotedblright} all caused substantial lesions in inoculated tanoak trees (average area 11.5 to 18.6 cm2). In all cases, the species used for inoculation was recovered on reisolation from lesion margins. Control inoculations caused necrotic areas averaging 0.2 cm2. Isolations from these areas were clean. Prior to the recent SOD epidemic, no species of Phytophthora were known as pathogens of tanoak. The discovery of P. ramorum as a pathogen of tanoak in California was quickly followed by the discovery that P. nemorosa and P. pseudosyringae were also associated with tanoak cankers (2). Six years of diagnostic support for survey and detection of P. ramorum in tanoak forests of southwest Oregon has revealed the occurrence, at very low frequency, of at least five additional species of Phytophthora causing stem cankers in tanoak.

}, url = {http://dx.doi.org/10.1094/PDIS-92-8-1252B}, author = {Reeser, Paul W. and Sutton, W. and Hansen, E.M.} } @article {4186, title = {Phytophthora pluvialis, a new species from mixed tanoak-Douglas-fir forests of western Oregon, U.S.A.}, journal = {North American Fungi}, volume = {8(7)}, year = {2013}, month = {May/2013}, pages = {1-8}, abstract = {

A new species, Phytophthora pluvialis is described. P. pluvialis has been recovered from streams, soil and canopy drip in the mixed tanoak-Douglas-fir forest in Curry County, Oregon, and in two additional streams in other areas of western Oregon. It has been found only rarely in association with twig and stem cankers on tanoak but not with any other plant host. The earliest isolate of P. pluvialis was from soil in 2002. P. pluvialis is classified in ITS Clade 3.

}, keywords = {canopy drip, environmental Phytophthora, oomycetes, rainwater, soil, streams}, doi = {10.2509/naf2013.008.007}, url = {http://dx.doi.org/10.2509/naf2013.008.007}, author = {Reeser, P. and Sutton, Wendy and Hansen, Everett} } @article {4659, title = {Phytophthora species in forest streams in Oregon and Alaska}, journal = {Mycologia}, volume = {103}, year = {2011}, month = {Aug-01-2012}, pages = {22 - 35}, abstract = {

Eighteen Phytophthora species and one species of Halophytophthora were identified in 113 forest streams in Alaska, western Oregon and southwestern Oregon that were sampled by baiting or filtration of stream water with isolation on selective media. Species were identified by morphology and DNA characterization with single strand conformational polymorphism, COX spacer sequence and ITS sequence. ITS Clade 6 species were most abundant overall, but only four species, P. gonapodyides (37\% of all isolates), P. taxon Salixsoil, P. taxon Oaksoil and P. pseudosyringae, were found in all three regions. The species assemblages were similar in the two Oregon regions, but P. taxon Pgchlamydo was absent in Alaska and one new species present in Alaska was absent in Oregon streams. The number of Phytophthora propagules in Oregon streams varied by season and in SW Oregon, where sampling continued year round, P. taxon Salixsoil, P. nemorosa and P. siskiyouensis were recovered only in some seasons.

}, issn = {0027-5514}, doi = {10.3852/10-013}, url = {https://www.tandfonline.com/doi/pdf/10.3852/10-013}, author = {Reeser, Paul W. and Sutton, Wendy and Hansen, Everett M. and Remigi, Philippe and Adams, Gerry C.} } @proceedings {225, title = {Phytophthora species in tanoak trees, canopy drip, soil, and streams in the sudden oak death epidemic area in southwestern Oregon.}, year = {2010}, publisher = {N. Z. J. Forestry}, address = {Auckland and Rotorua, New Zealand}, author = {Reeser, Paul and Sutton, Wendy and Everett Hansen} } @proceedings {reeser2010phytophthora, title = {Phytophthora siskiyouensis, a new species from soil and water in southwest Oregon}, volume = {General Technical Report PSW-GTR-214}, year = {2010}, month = {03/2008}, pages = {439{\textendash}441}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, Albany, CA}, address = {Santa Rosa, CA}, keywords = {coast live oak, invasive species, Phytophthora ramorum, Sudden oak death, tanoak}, url = {http://www.fs.fed.us/psw/publications/documents/psw_gtr214/}, author = {P. Reeser and E. Hansen and Sutton, W.}, editor = {Susan J. Frankel and John T. Kliejunas and Katharine M. Palmieri} } @article {PaulW.Reeser01012011, title = {Phytophthora species in forest streams in Oregon and Alaska}, journal = {Mycologia}, volume = {103}, number = {1}, year = {2011}, pages = {22-35}, abstract = {

Eighteen Phytophthora species and one species of Halophytophthora were identified in 113 forest streams in Alaska, western Oregon and southwestern Oregon that were sampled by baiting or filtration of stream water with isolation on selective media. Species were identified by morphology and DNA characterization with single strand conformational polymorphism, COX spacer sequence and ITS sequence. ITS Clade 6 species were most abundant overall, but only four species, P. gonapodyides (37\% of all isolates), P. taxon Salixsoil, P. taxon Oaksoil and P. pseudosyringae, were found in all three regions. The species assemblages were similar in the two Oregon regions, but P. taxon Pgchlamydo was absent in Alaska and one new species present in Alaska was absent in Oregon streams. The number of Phytophthora propagules in Oregon streams varied by season and in SW Oregon, where sampling continued year round, P. taxon Salixsoil, P. nemorosa and P. siskiyouensis were recovered only in some seasons.

}, doi = {10.3852/10-013}, url = {http://www.mycologia.org/cgi/content/abstract/103/1/22}, author = {Reeser, Paul W. and Sutton, Wendy and Hansen, Everett M. and Remigi, Philippe and Adams, Gerry C.} } @proceedings {431, title = {Phytophthora species associated with stem cankers on tanoak in southwestern Oregon}, year = {2007}, address = {Santa Rosa CA}, author = {P. Reeser and Sutton, W. and Hansen, E.M.} } @article {doi:10.1094/PDIS.2002.86.3.205, title = {Phytophthora ramorum as the cause of extensive mortality of Quercus spp. and Lithocarpus densiflorus in California}, journal = {Plant Disease}, volume = {86}, number = {3}, year = {2002}, pages = {205-214}, abstract = {

A new canker disease, commonly known as sudden oak death, of Lithocarpus densiflorus, Quercus agrifolia, Q. kelloggii, and Q. parvula var. shrevei in California is shown to be caused by Phytophthora ramorum. The pathogen is a recently described species that previously was known only from Germany and the Netherlands on Rhododendron spp. and a Viburnum sp. This disease has reached epidemic proportions in forests along approximately 300 km of the central coast of California. The most consistent and diagnostic symptoms on trees are cankers that develop before foliage symptoms become evident. Cankers have brown or black discolored outer bark and seep dark red sap. Cankers occur on the trunk at the root crown up to 20 m above the ground, but do not enlarge below the soil line into the roots. Individual cankers are delimited by thin black lines in the inner bark and can be over 2 m in length. In L. densiflorus saplings, P. ramorum was isolated from branches as small as 5 mm in diameter. L. densiflorus and Q. agrifolia were inoculated with P. ramorum in the field and greenhouse, and symptoms similar to those of naturally infected trees developed. The pathogen was reisolated from the inoculated plants, which confirmed pathogenicity.

}, doi = {10.1094/PDIS.2002.86.3.205}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2002.86.3.205}, author = {D. M. Rizzo and Garbelotto, M. and J. M. Davidson and Slaughter, G. W. and Koike, S. T.} } @article {rizzo2005phytophthora, title = {Phytophthora ramorum: integrative research and management of an emerging pathogen in California and Oregon forests}, journal = {Annual Review of Phytopathology}, volume = {43}, number = {1}, year = {2005}, pages = {309}, abstract = {

Phytophthora ramorum, causal agent of sudden oak death, is an emerging plant pathogen first observed in North America associated with mortality of tanoak (Lithocarpus densiflorus) and coast live oak (Quercus agrifolia) in coastal forests of California during the mid-1990s. The pathogen is now known to occur in North America and Europe and have a host range of over 40 plant genera. Sudden oak death has become an example of unintended linkages between the horticultural industry and potential impacts on forest ecosystems. This paper examines the biology and ecology of P. ramorum in California and Oregon forests as well discussing research on the pathogen in a broader management context.

}, doi = {10.1146/annurev.phyto.42.040803.140418}, url = {http://www.annualreviews.org/toc/phyto/43/1}, author = {D. M. Rizzo and Garbelotto, M. and Hansen, E.M.} } @article {4238, title = {Pathogenicity of Phytophthora lateralis lineages on resistant and susceptible selections of Chamaecyparis lawsoniana}, journal = {Plant Disease}, year = {2014}, month = {Oct-10-2015}, abstract = {

Phytophthora lateralis, the cause of Chamaecyparis lawsoniana root disease, was introduced in North America about 1950, and has since killed trees along roads and streams throughout the tree{\textquoteright}s range. Recent results suggest an Asian origin for this Oomycete and four genetic lineages were identified. This raised questions for the genetic exapted resistance demonstrated in 1989 within the wild population of C. lawsoniana but with only one P. lateralis lineage. The main goal of the present research was to test the durability of the demonstrated resistance and to compare the pathogenicity of isolates representing the four lineages. No breakdown of resistance was observed in five separate tests using different inoculation techniques, resistant and susceptible C. lawsoniana trees, and seedling families. Differences in mortality and lesion length were observed between the lineages. The higher aggressiveness of isolates of the TWJ and PNW lineages and the lower aggressiveness of the TWK lineage are discussed in view of the hypotheses on the history of spread and evolutionary history of the P. lateralis lineages.

}, issn = {0191-2917}, doi = {10.1094/PDIS-07-14-0720-RE}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-14-0720-RE}, author = {Robin, C{\'e}cile and Brasier, Clive and Reeser, Paul W and Sutton, Wendy and Vannini, Andrea and Vettraino, Anna Maria and Hansen, Everett} } @article {4492, title = {Potential risk of occurrence of Phytophthora alni in forests of the Czech Republic}, journal = {Journal of Maps}, year = {2016}, month = {Jun-06-2018}, pages = {1 - 5}, abstract = {

Phytophthora alni is an invasive organism that causes root and collar rot in alders, which significantly damages the forest and riparian vegetation of alder trees in Central and Western Europe. In the Czech Republic, this pathogen was first confirmed in 2001, and since then it has been gradually spreading from the west to the east. Here, we applied a model of potential distribution that estimates the level and spatial variability of the pathogen occurrence and spread risk for Czech Republic forests to target the early detection and control the further invasion of P. alni in this region. Our predictions are based on a rigorous statistical analysis of data obtained from field survey as well as available geodatabases. We used two sets of predictor variables describing (i) the forest stands and (ii) neighbourhood of the stands, and generalized linear modelling with forward stepwise selection of predictors. The results of statistical analysis showed the significant effect of the area of the forest stand, forest vegetation zone, presence of watercourse and area of alder stands in the neighbourhood on the probability of occurrence of P. alni in the study region. The map derived based on the final model shows the potential risk of occurrence and impact of P. alni in forests of the Czech Republic as classified on a five-point scale ranging from very low risk for alder stands with a low level of likely invasion to very sensitive alder stands with high probability of pathogen occurrence and high levels of damage. This is a unique output not only for the Czech Republic but also throughout Europe.

}, doi = {10.1080/17445647.2016.1198996}, url = {http://www.tandfonline.com/doi/full/10.1080/17445647.2016.1198996}, author = {Romportl, Du{\v s}an and Chumanov{\'a}, Eva and Havrdov{\'a}, Ludmila and Pe{\v s}kov{\'a}, V{\'\i}t{\v e}zslava and {\v C}ern{\'y}, Karel} } @article {Roth:1 June 1966:0015-749X:147, title = {Phytophthora cinnamomi, an unlikely threat to Douglas-fir forestry}, journal = {Forest Science}, volume = {12}, year = {1966}, pages = {147-159(13)}, abstract = {

Phytophthora cinnamomi has damaged forests around the world in regions with mild climates. Its pathogenesis on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in southern Europe and southeastern United States suggested a potential threat to Douglas-fir forests of the Pacific Coast. Concern increased in 1950 with discovery of P. cinnamomi in nurseries growing ornamentals and in landscape plantings in western Oregon and Washington and research was undertaken to evaluate the threat. A temperature of 60{\textdegree} F was found necessary for infection. While summer soil temperatures on south exposures are above 60{\textdegree} F most of the time from June to October soil moisture is continuously below field capacity and too dry for infection. On north exposures summer soil moisture is adequate but temperatures are too low; 60{\textdegree} F is reached for only a few hours near the first of August. Forest soils of western Oregon are generally too dry for infection during the summer. The fall rains provide necessary moisture but concurrently depress temperatures below the critical 60{\textdegree} F. Adverse soil temperature and moisture influence disease by impeding infection rather than reducing survival of P. cinnamomi. The disease in ornamentals is sustained by summer irrigation of warm locations such as the south side of buildings. The data show that P. cinnamomi is unlikely to become a problem in forests of the Pacific Northwest.

}, url = {http://www.ingentaconnect.com/content/saf/fs/1966/00000012/00000002/art00005}, author = {Roth, Lewis F. and Kuhlman, E. George} } @article {241, title = {Port-Orford-cedar disease}, year = {1987}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Northwest Region}, issn = {Forest Pest Management Report No. R6 FPM PR 010 91}, url = {http://www.fs.fed.us/r6/nr/fid/fidls/poc.htm}, author = {L.F. Roth and Harvey,R.D. and J.T. Kliejunas} } @article {2753228920071201, title = {Phytophthora cambivora in Oregon and its pathogenicity to Chrysolepis chrysophylla.}, journal = {Forest Pathology}, volume = {37}, number = {6}, year = {2007}, pages = {409 - 419}, abstract = {

A new canker disease causing mortality of golden chinquapin trees [Chrysolepis chrysophylla (Dougl.) Hjelmqvist], in Oregon was recently observed. Most of the symptomatic or dead trees were located near roads. The cankers on the lower boles of trees are similar to those caused by species of Phytophthora on other trees in western North America. The cankers in the inner bark were reddish-orange in colour and extended upward from necrotic roots. Phytophthora (Petri) Buisman was isolated from the cankers; identity was confirmed by morphological comparison with known isolates and internal transcribed spacer sequence analysis. Pathogenicity was confirmed by inoculation of chinquapin seedlings and mature trees. Seven of nine isolates from chinquapin were A2 mating type; 27 of 28 isolates from other hosts in Oregon and Washington were A1 mating type.

}, keywords = {Biodiversity, Canker (Plant disease), diseases, Forests. forestry, Oregon, Pathogenic microorganisms, pests, PLANT diseases}, issn = {14374781}, doi = {10.1111/j.1439-0329.2007.00515.x}, url = {http://onlinelibrary.wiley.com.proxy.library.oregonstate.edu/doi/10.1111/j.1439-0329.2007.00515.x/abstract}, author = {Saavedra, A. and Hansen, E.M. and Goheen, D. J.} } @article {EFP:EFP261, title = {Phytophthora disease of Quercus ilex in south-western Spain}, journal = {Forest Pathology}, volume = {32}, number = {1}, year = {2002}, pages = {5{\textendash}18}, publisher = {Blackwell Science Ltd.}, abstract = {

Oak decline that was affecting three holm oak sites in the province of Huelva (south-western Spain) was studied during 1998{\textendash}1999. The syndromes of dieback and sudden death have been observed and, in both cases, foliar symptoms were associated with root rot. Characterization of the fungal isolates from necrotic roots led us to identify Phytophthora cinnamomi A2 as consistently associated with the disease. The optimum growth temperatures of these isolates were very high (30{\textdegree}C). Inoculation tests under controlled conditions demonstrated the pathogenicity of the isolates on holm and cork oak seedlings. None of the other biotic factors of Mediterranean oak decline that have been previously described were found in the present study and so, in this case, the forest decline model does not seem to be necessary in order to explain the disease observed. The defoliation and mortality of the oaks was primarily caused by P. cinnamomi, although some abiotic factors such as alternating periods of drought and wet weather in the region may play an important role.

}, issn = {1439-0329}, doi = {10.1046/j.1439-0329.2002.00261.x}, url = {http://dx.doi.org/10.1046/j.1439-0329.2002.00261.x}, author = {Sanchez, M. E. and Caetano, P. and Ferraz, J. and Trapero, A.} } @article {4471, title = {Phytophthora kernoviae isolated from fallen leaves of Drymis winteri in native forest of southern Chile}, journal = {Australasian Plant Disease Notes}, volume = {11}, year = {2016}, month = {Jan-06-2016}, abstract = {

Phytophthora kernoviae is an invasive species first described from Britain and later New Zealand. We conducted surveys for Phytophthora species in forests in southern Chile. Symptomatic fallen leaves of Drimys winteri were encountered in a native forest. P. kernoviae was isolated. This is the first report of P. kernoviae outside of UK and New Zealand.

}, doi = {10.1007/s13314-016-0205-6}, url = {http://link.springer.com/10.1007/s13314-016-0205-6}, author = {Sanfuentes, E. and Fajardo, S. and Sabag, M. and Hansen, E. and Gonz{\'a}lez, M.} } @article {388, title = {Pathogenicity of four Phytophthora species on wild cherry and Italian alder seedlings}, journal = {Journal of Phytopathology}, volume = {154}, year = {2006}, month = {03/2006}, pages = {163{\textendash}167}, abstract = {

Abstract Inoculation tests were carried out in the greenhouse on wild cherry (Prunus avium) and Italian alder (Alnus cordata) seedlings, to determine their susceptibility to certain Phytophthora species (P. citrophthora, P. alni, P. megasperma and P. cinnamomi) that are commonly present in the soil. Host susceptibility was evaluated in accordance with a disease index, with the lesion length after stem inoculation, and with a root system disease index. Wild cherry was found to be highly susceptible to P. citrophthora, and was also found to be susceptible to P. alni, although to a lesser extent. Italian alder was very susceptible to P. alni, but had only low susceptibility to P. citrophthora. The other Phytophthora species caused only modest symptoms. The danger to alder and wild cherry is all the greater because these trees not only share the same pathogens, but also commonly planted together in mixed stands. The results will now have to be confirmed by using a more natural inoculation method.

}, keywords = {Alnus cordata, inoculation test, pathogenicity, Phytophthora, Prunus avium}, doi = {10.1111/j.1439-0434.2006.01077.x}, url = {http://dx.doi.org/10.1111/j.1439-0434.2006.01077.x}, author = {Santini, A. and Biancalani, F. and Barzanti, G. P. and Capretti, P.} } @article {4514, title = {Phytophthora nicotianae: agente etiol{\'o}gico da gomose da ac{\'a}cia negra no Brasil}, journal = {Fitopatologia Brasileira}, volume = {30}, year = {2005}, pages = {81{\textendash}4}, abstract = {

A gomose, causada por Phytophthora sp., {\'e} a mais importante enfermidade da ac{\'a}cia-negra (Acacia mearnsii) no Rio Grande do Sul, Brasil. A identifica{\c c}{\~a}o espec{\'\i}fica permanecia indeterminada. Procurou-se, ent{\~a}o, identificar a esp{\'e}cie de Phytophthora causadora desta doen{\c c}a no Rio Grande do Sul, usando caracter{\'\i}sticas fisiomorfol{\'o}gicas e estudos moleculares baseados no seq{\"u}enciamento das regi{\~o}es de Internal Transcribed Spacer (ITS). A patogenicidade dos isolados estudados para a ac{\'a}cia-negra foi confirmada. Os estudos confirmaram Phytophthora nicotianae como a correta identidade dos isolados fitopatog{\^e}nicos. Este {\'e} o primeiro relato de P. nicotianae em ac{\'a}cia-negra no Brasil.

Gummosis caused by Phytophthora sp. is the most important disease of black wattle (Acacia mearnsii) in Rio Grande do Sul, Brazil. Isolates of Phytophthora sp. associated with diseased plants were obtained from Rio Grande do Sul and their pathogenicity was confirmed. In order to elucidate the correct identity of the fungus at the species level physiomorphological characteristics were determined and molecular studies were conducted based on sequences of Internal Transcribed Spacer (ITS) region. The fungus was identified as Phytophthora nicotianae. This is the first report of P. nicotianae on black wattle in Brazil.

}, issn = {1982-5676 }, doi = {10.1590/s0100-41582005000100015 }, url = {https://doi.org/10.1590/s0100-41582005000100015 }, author = {Santos, A. F. dos and Luz, EDMN and Souza, J. T.} } @conference {4526, title = {Phytophthora spp: distribui{\c c}{\~a}o e associa{\c c}{\~a}o com esp{\'e}cies florestais}, booktitle = {Congresso Brasileiro de Fitopatologia, 47}, year = {2014}, publisher = {Sociedade Brasileira de Fitopatologia}, organization = {Sociedade Brasileira de Fitopatologia}, address = {Londrina, Brazil}, url = {http://www.alice.cnptia.embrapa.br/handle/doc/993792}, author = {Santos, A. F. dos and Luz, EDMN and Reis, A.} } @article {SANTOS2004, title = {Primeiro relato da podrida da estipe da pupunheira, causada por Phytophthora palmivora, no estado do Parana{\textquoteleft}}, journal = {Fitopatologia Brasileira}, volume = {29}, year = {2004}, month = {12}, pages = {680 - 682}, publisher = {scielo}, abstract = {

Phytophthora palmivora was isolated from infected peach palm (Bactris gasipaes) plants with stem rot symptoms in Paran{\'a} State, in 2002. Pathogenicity tests and subsequent reisolations of P. palmivora confirmed the hypothesis that this fungus was the causal agent of the disease. This is the first report of P. palmivora causing stem rot on peach palm (Bactris gasipaes) in the southern State of Paran{\'a}. RESUMO Phytophthora palmivora foi isolado de plantas de pupunheira (Bactris gasipaes) com sintomas de podrid{\~a}o da estipe, no Paran{\'a}, em 2002. Testes de patogenicidade e o subseq{\"u}ente reisolamento do fungo confirmaram a hip{\'o}tese de que P. palmivora {\'e} o agente causal da podrid{\~a}o do estipe. Este {\'e} o primeiro relato de P. palmivora causando podrid{\~a}o do estipe na pupunheira no estado do Paran{\'a}.

}, issn = {0100-4158}, url = {http://www.scielo.br/scielo.php?script=sci_arttext\&pid=S0100-41582004000600016\&nrm=iso}, author = {Santos, A. F. dos and Luz, Edna Dora. M. N. and Finato, Priscila D. and Tessmann, Dauri J. and Vida, J. B.} } @article {4086, title = {Phytophthora species associated with diseased woody ornamentals in Minnesota nurseries}, journal = {Plant Disease}, volume = {91}, year = {2007}, month = {01/2007}, pages = {97 - 102}, abstract = {

Phytophthora species are responsible for causing extensive losses of ornamental plants worldwide. Recent international and national surveys for the detection of P. ramorum have led to the finding of previously undescribed Phytophthora species. Since no previous Phytophthora surveys have been carried out in Minnesota, surveys of ornamental nurseries were performed over 4 years to isolate and identify the Phytophthora species causing diseases of woody plants in Minnesota. Species were identified by direct sequencing of internal transcribed spacer (ITS) rDNA, β-tub, and mitochondrial coxI genes. Species associated with diseased ornamental plants include P. cactorum, P. cambivora, P. citricola, P. citrophthora, P. hedraiandra, P. megasperma, P. nicotianae, and the previously identified but undescribed taxon P. Pgchlamydo. The most common species encountered were P. cactorum, P. citricola, and P. citrophthora. Two additional isolates obtained did not match known species. One was similar to P. alni subsp. alni, and the other appeared to be a new species and is referred to as P. sp. MN1. In addition, species are reported for the first time from several hosts. Results indicated that several Phytophthora species were more widespread in the nursery industry than previously thought, and undescribed species were causing disease in Minnesota ornamental nurseries.

}, issn = {0191-2917}, doi = {10.1094/PD-91-0097}, url = {http://dx.doi.org/10.1094/PD-91-0097 }, author = {Schwingle, B. W. and Smith, J. A. and Blanchette, R. A.} } @article {Scott:30 June 2009:0031-5850:1, title = {Phytophthora multivora sp. nov., a new species recovered from declining Eucalyptus, Banksia, Agonis and other plant species in Western Australia}, journal = {Persoonia - Molecular Phylogeny and Evolution of Fungi}, volume = {22}, year = {2009}, pages = {1-13(13)}, abstract = {

A new Phytophthora species, isolated from rhizosphere soil of declining or dead trees of Eucalyptus gomphocephala, E. marginata, Agonis flexuosa, and another 13 plant species, and from fine roots of E. marginata and collar lesions of Banksia attenuata in Western Australia, is described as Phytophthora multivora sp. nov. It is homothallic and produces semipapillate sporangia, smooth-walled oogonia containing thick-walled oospores, and paragynous antheridia. Although morphologically similar to P. citricola, phylogenetic analyses of the ITS and cox1 gene regions demonstrate that P. multivora is unique. Phytophthora multivora is pathogenic to bark and cambium of E. gomphocephala and E. marginata and is believed to be involved in the decline syndrome of both eucalypt species within the tuart woodland in south-west Western Australia.

}, doi = {10.3767/003158509X415450}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789538/}, author = {P.M. Scott and Burgess, T. I. and P.A. Barber and Shearer, B. L. and Stukely, M. J. C. and G.E.St.J. Hardy and T. Jung} } @article {4236, title = {Phytophthora diseases in New Zealand forests}, journal = {New Zealand Journal of Forestry}, volume = {59}, year = {2014}, pages = {14-21}, abstract = {

This article provides a brief overview of the status of Phytophthora diseases in New Zealand forests. Recent outbreaks of Phytophthora diseases internationally and within these forests, including Red Needle Cast of Pinus radiata caused by Phytophthora pluvialis and Agathis australis (kauri) dieback caused by Phytophthora taxon Agathis (PTA), have highlighted the biosecurity threat these species pose to New Zealand. In isolated cases, Red Needle Cast has impacted P. radiata plantations through the premature defoliation of mature needles. Kauri dieback, caused by Phytophthora taxon Agathis, has resulted in devastating disease within some sites. Preliminary research indicates that both these diseases will respond to treatment with phosphite, consistent with current international Phytophthora management. Ongoing research into Red Needle Cast, Phytophthora taxon Agathis induced kauri dieback and other Phytophthora diseases within P. radiata and kauri is focusing on understanding the epidemiology of the diseases, the chemical and genetic mechanisms of resistance, and also screening for durable resistance to multiple Phytophthora species. Many other Phytophthora pathogens have been identified within New Zealand. These have not been found to cause serious disease in native or exotic forest systems, despite some being known to cause diseases of great consequence internationally. Significant examples include P. cinnamomi, P. multivora and P. kernoviae. As a result of increased global movement of plant material, New Zealand{\textquoteright}s and other international forests are vulnerable to new Phytophthora diseases. However, through the world{\textquoteright}s best practice adaptive management the threat and impacts of these diseases can be reduced.

}, url = {http://www.nzjf.org/abstract.php?volume_issue=j59_2\&first_page=14}, author = {Peter Scott and Nari Williams} } @article {EFP:EFP753, title = {Pathogenicity of Phytophthora multivora to Eucalyptus gomphocephala and Eucalyptus marginata}, journal = {Forest Pathology}, volume = {42}, year = {2011}, pages = {289{\textendash}298}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora multivora is associated with the rhizosphere of declining Eucalyptus gomphocephala, Eucalyptus marginata and Agonis flexuosa. Two pathogenicity experiments were conducted. The first experiment examined the pathogenicity of five P. multivora isolates and one Phytophthora cinnamomi isolate on the root systems of E. gomphocephala and one P. multivora isolate on the root system of E. marginata. In the second experiment, the pathogenicity of P. multivora to E. gomphocephala and E. marginata saplings was measured using under-bark stem inoculation. In Experiment 1, the P. cinnamomi isolate was more aggressive than all P. multivora isolates causing significant loss of fine roots and plant death. Two P. multivora isolates and the P. cinnamomi isolate caused significant losses of E. gomphocephala fine roots 0-2 mm in diameter and significantly reduced the surface area of roots 0-1 mm in diameter. One P. multivora and the P. cinnamomi isolate significantly reduced the surface area of roots 1-2 mm in diameter. Two of the P. multivora isolates significantly reduced the number of E. gomphocephala root tips. In E. marginata, the length and surface area of roots 0-1 mm in diameter and number of root tips were significantly reduced by P. multivora infestation. Rhizosphere infestation with the P. multivora isolates and P. cinnamomi isolate on E. gomphocephala, and one P. multivora isolate on E. marginata, did not significantly influence the foliar nutrient concentrations. In Experiment 2, under-bark inoculation with P. multivora caused significant lesion extension in E. gomphocephala and E. marginata saplings, compared to the control. We propose that P. multivora is inciting E. gomphocephala and E. marginata decline by causing fine root loss and subsequently interfering with nutrient cycling throughout the plant. The impact of fine root loss on the physiology of plants in sites infested with P. multivora requires further research.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00753.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00753.x}, author = {P.M. Scott and T. Jung and Shearer, B. L. and P.A. Barber and Calver, M. and Hardy, G. E. St. J.} } @article {4614, title = {Phytophthora Contamination in a Nursery and Its Potential Dispersal into the Natural Environment}, journal = {Plant Disease}, volume = {102}, year = {2018}, month = {Jan-01-2018}, pages = {132 - 139}, abstract = {

A detailed site investigation of a eucalypt nursery suffering disease losses revealed the causal agent to be Phytophthora boodjera. The pathogen was detected in vegetation surrounding the nursery production area, including the lawn, under the production benches during the growing season, and, most importantly, from plant debris in used trays. However, it was not found in the container substrate, water supplies, or production equipment or on the workers themselves. The sterilization methods used by the nursery were shown to be ineffective, indicating that a more rigorous method was required. Boiling trays for 15 min or steaming at 65{\textdegree}C for 60 min eradicated P. boodjera. This pathogen was more pathogenic to the eucalypts tested in their early seedling stage than P. cinnamomi. Tracing of out-planting to revegetation sites showed that P. boodjera was able to spread into the environment. Dispersal via out-planting to native vegetation may affect seedling recruitment and drive long-term shifts in native plant species. Inadequate nursery hygiene increases the risk of an outbreak and can limit the success of biosecurity efforts as well as damage conservation efforts.

}, issn = {0191-2917}, doi = {10.1094/PDIS-05-17-0689-RE}, url = {https://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-05-17-0689-RE}, author = {Simamora, Agnes V. and Paap, Trudy and Howard, Kay and Stukely, Michael J. C. and Hardy, Giles E. St. J. and Burgess, Treena I.} } @mastersthesis {4649, title = {Phytophthora species and riparian alder tree damage in western Oregon}, volume = {Ph.D.}, year = {2013}, month = {02/2014}, abstract = {

The genus Phytophthora contains some of the most destructive pathogens of forest trees, including the most destructive pathogen of alder in recent times, Phytophthora alni. Alder trees were reported to be suffering from canopy dieback in riparian ecosystems in western Oregon, which prompted a survey of alder health and monitoring for P. alni. In 2010 surveys in western Oregon riparian ecosystems were initiated to gather baseline data on damage and on the Phytophthora species associated with alder. Damage was recorded and analyzed from transects containing alder trees with canopy dieback symptoms according to damage type: (1) pathogen, (2) insect, or (3) wound. Phytophthora species from western Oregon riparian ecosystems were systematically sampled, isolated, identified, stored and compared. Koch{\textquoteright}s Postulates were evaluated for three key Phytophthora species recovered: P. alni, P. siskiyouensis and P. taxon Oaksoil, and alder disease in the western United States was described. Then, the ecological role of the most abundant Phytophthora species from streams was evaluated. The data indicated that many of the same agents reported causing damage to alder trees in the western United States were also damaging alder trees in western Oregon including the alder flea beetle, sawflies, flood debris, Septoria alnifolia, and Mycopappus alni. The most important damage correlated with canopy dieback was incidence of Phytophthora cankers, and isolation of Phytophthora siskiyouensis. In the initial systematic survey of Phytophthora species, 1190 individual Phytophthora isolates were recovered but were of many different species. In the survey of alder roots, P. alni subsp. uniformis was one of the species recovered from necrotic red alder roots, but overall incidence was low; it was isolated four times. From the evaluation of Koch{\textquoteright}s postulates, Phytophthora canker of alder in the western United States was described, and is a bole canker caused by Phytophthora. Phytophthora canker of alder was only found caused by P. siskiyouensis in nature, and it was isolated 74 times. Isolation was mainly from bole cankers and diseased roots on red and white alder, and from water and alder leaf debris floating in the stream. The most abundant Phytophthora species associated with red alder is an informally described species P. taxon Oaksoil, which appears to be a relatively benign aquatic saprotroph of alder leaf debris. Canopy dieback was more prevalent in riparian alder trees from transects with P. siskiyouensis than from transects with P. taxon Oaksoil but without P. siskiyouensis (70\% and 35\%, respectively). The informally described P. taxon Oaksoil from western Oregon is formally described here as P. obrutafolium sp. nov., closely related to P. bilorbang from western Australia, and P. taxon Oaksoil ss from an oak forest in France. In summary, other agents besides Phytophthora can damage alder trees in western Oregon. Many Phytophthora species associate with alder in western Oregon but not all of them are important damaging agents of alder. However, Phytophthora canker of alder is widespread in western Oregon. In the United States, Phytophthora canker of alder has only been found to be caused by P. siskiyouensis.

}, url = {http://hdl.handle.net/1957/46441 }, author = {Sims, Laura} } @article {4342, title = {The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA}, journal = {Mycologia}, volume = {107}, year = {2015}, month = {October 2015}, pages = {889 - 902}, abstract = {

Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described {\textquotedblleft}P. taxon Pgchlamydo{\textquotedblright}, and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in down- stream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described {\textquotedblleft}P. taxon Oaksoil{\textquotedblright}, which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides.

}, issn = {0027-5514}, doi = {10.3852/14-255}, url = {http://www.mycologia.org/cgi/doi/10.3852/14-255}, author = {Sims, L. L. and Sutton, W. and Reeser, P. and Hansen, E. M.} } @article {3963, title = {Phytophthora alni on Alnus glutinosa reported for the first time in Spain}, journal = {Plant Pathology}, volume = {59}, year = {2010}, month = {08/2010}, pages = {798 - 798}, doi = {10.1111/ppa.2010.59.issue-410.1111/j.1365-3059.2009.02254.x}, author = {Solla, A. and P{\'e}rez-Sierra, A. and Corcobado, T. and Haque, M. M. and Diez, J. J. and T. Jung} } @article {859, title = {Phytophthora katsurae. [Descriptions of Fungi and Bacteria].
}, journal = {IMI Descriptions of Fungi and Bacteria}, volume = {84}, year = {1985}, pages = {Sheet 837}, abstract = {

A description is provided for Phytophthora katsurae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Chestnut, coconut. DISEASE: Trunk rot of chestnut. GEOGRAPHICAL DISTRIBUTION: Asia (Japan, Taiwan), Oceania (Hawaii), Africa (Ivory Coast), Australasia (Australia (Queensland), Papua New Guinea). TRANSMISSION: Soil-borne, isolated from forest soils in Taiwan (59, 2349), Queensland and Papua New Guinea and from chestnut orchard soils in Japan (58, 2951).

}, author = {Stamps, D. J.} } @article {EFP:EFP282, title = {Phytophthora disease of alder (Alnus glutinosa) in France: investigations between 1995 and 1999}, journal = {Forest Pathology}, volume = {32}, number = {3}, year = {2002}, pages = {179{\textendash}191}, publisher = {Blackwell Verlag GmbH}, abstract = {

A severe decline of alder associated with an undescribed Phytophthora species was identified for the first time in England in 1993. No generalized decline of alder was reported in France before 1990. The first diebacks and mortalities of common alder were observed at the beginning of the 1990s, but the so-called alder Phytophthora was not isolated in France until 1996. First, a synthesis about alder declines that were known in France before 1995 is presented. Then, a survey was established in north-eastern France; 108 sites were visited and the alder Phytophthora was isolated from 57 of them. All the main rivers were found to be affected and damage levels are significant along some of them. The frequency of the alder Phytophthora and other fungi isolated from declining alders is discussed. Finally, information on other alder declines in France is presented region by region, and a map summarizes the known distribution of the disease. The alder Phytophthora is quite common and widespread in France, with western and north-eastern France being especially affected; however, the number of diseased or dead trees varies greatly from one site to another. All records are from Alnus glutinosa; other Alnus species were seldom seen in the surveys.

}, issn = {1439-0329}, doi = {10.1046/j.1439-0329.2002.00282.x}, url = {http://dx.doi.org/10.1046/j.1439-0329.2002.00282.x}, author = {Streito, J-C. and Legrand, PH. and Tabary, F. and De Villartay, G. Jarnouen} } @article {4467, title = {Phytophthora ramorum can survive introduction into finished compost}, journal = {California Agriculture}, volume = {69}, year = {2015}, month = {Jan-10-2015}, pages = {237 - 241}, abstract = {

Composted municipal green waste is a potential vehicle for the transmission of Phytophtora ramorum, the pathogen responsible for the disease known as sudden oak death. To assess the survival rate of the pathogen in compost, we introduced zoospores {\textemdash} a type of infectious propagule {\textemdash} into six composts of varying provenance and maturity. The compost samples represented three production facilities, two production techniques (turned windrow and forced air static pile) and two levels of maturity (fresh, defined as aged for less than 1 week; and mature, aged for more than 4 weeks). Positive re-isolations {\textemdash} indicating survival of the pathogen {\textemdash} were obtained from all composts. The re-isolation rate from the compost from one of the three production facilities was greater than that obtained from an inert substrate (filter paper) inoculated with the pathogen (P \< 0.01), while re-isolation rates from the other two sources were statistically indistinguishable from those obtained from the inert substrate (P \< 0.01). There was no significant difference in re-isolation rate between composts produced by the turned windrow method and composts produced by the forced air static pile technique. Re-isolation rates were greater from mature composts than from fresh composts (P \< 0.01). The results show that P. ramorum may be present and infectious if introduced into finished compost, and that variations in compost characteristics appear to influence survival rates.

}, issn = {0008-0845}, doi = {10.3733/ca.v069n04p237}, url = {http://californiaagriculture.ucanr.edu/landingpage.cfm?articleid=ca.v069n04p237}, author = {Swain, Steven and Garbelotto, Matteo} } @article {doi:10.1094/PDIS.2000.84.4.394, title = {Phytophthora cinnamomi as a cause of oak mortality in the state of Colima, Mexico}, journal = {Plant Disease}, volume = {84}, number = {4}, year = {2000}, pages = {394-398}, doi = {10.1094/PDIS.2000.84.4.394}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2000.84.4.394}, author = {Tainter, F. H. and O{\textquoteright}Brien, J. G. and Hern{\'a}ndez, A. and Orozco, F. and Rebolledo, O.} } @article {4444, title = {Phytophthora cambivora found on beech in Norway}, journal = {Forest Pathology}, volume = {45}, year = {2015}, month = {Jan-10-2015}, pages = {415 - 425}, abstract = {

In 2011, Phytophthora cambivora was isolated for the first time from a European beech (Fagus sylvatica) in the largest beech forest in Norway, in Larvik. This led to a survey of Phytophthora, both in Larvik and in a small beech stand in {\r A}s. Both locations are in urban areas\ in south-eastern Norway. Trees with a circumference above 20\ cm at chest height were examined for bleeding cankers. Samples from the leading edge of canker wounds were collected from selected trees in both locations and isolations were carried out on a Phytophthora-selective medium. Quantification of diseased trees in three areas of the forest in Larvik showed a variation from 1.8 to 22.7\% trees with bleeding cankers. In {\r A}s, 9.2\% of the trees had bleeding cankers. Isolation from diseased beech in both Larvik and {\r A}s yielded P.\ cambivora. Inoculation of healthy trees, subsequent development of disease and re-isolation of the pathogen confirmed the pathogenicity of P.\ cambivora. Description of morphological features of one of the obtained isolates is included.

}, doi = {10.1111/efp.2015.45.issue-510.1111/efp.12215}, url = {http://doi.wiley.com/10.1111/efp.2015.45.issue-5http://doi.wiley.com/10.1111/efp.12215http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fefp.12215}, author = {Telfer, K. H. and Brurberg, M. B. and Herrero, M.-L. and Stensvand, A. and {\o}, V.}, editor = {Desprez-Loustau, M.-L.} } @article {4483, title = {Phytophthora species isolated from ash stands in Bia{\l}owie{\.z}a Forest nature reserve}, journal = {Forest Pathology}, year = {2016}, month = {Jan-06-2016}, abstract = {

Five Phytophthora species were isolated from the rhizosphere of ash-dominated areas of the Bia{\l}owieza European lowland forest nature reserve area. Morphological and DNA analyses identified Phytophthora fragariaefolia, P.\ plurivora, P.\ cactorum, P.\ lacustris and P.\ pseudosyringae. This is the first record of P.\ fragariaefolia in ash forests and demonstrates that several species in the potentially highly damaging Phytophthora genus are present within a near-pristine ecosystem.

}, doi = {10.1111/efp.12295}, url = {http://doi.wiley.com/10.1111/efp.12295http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fefp.12295}, author = {Tkaczyk, M. and Nowakowska, J. A. and Oszako, T.} } @article {259, title = {Phytophthora root rot diseases of Lawson cypress and other ornamentals}, year = {1954}, pages = {18 p.}, publisher = {Oregon State College. Agricultural Experiment Station}, address = {Corvallis, OR}, keywords = {Diseases and pests, Ornamental trees}, issn = {StationBulletin537}, url = {http://hdl.handle.net/1957/15349}, author = {Torgeson, D. C. and Young, Roy A. and Milbrath, John A.} } @article {196, title = {The pathology of Phytophthora lateralis on native Chamaecyparis lawsoniana}, journal = {Phytopathology}, volume = {49}, year = {1959}, pages = {306{\textendash}310}, author = {Trione, E. J.} } @article {Tyler01092006, title = {Phytophthora genome sequences uncover evolutionary origins and mechanisms of pathogenesis}, journal = {Science}, volume = {313}, number = {5791}, year = {2006}, pages = {1261-1266}, abstract = {

Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum. Oomycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms, and the presence of many Phytophthora genes of probable phototroph origin supports a photosynthetic ancestry for the stramenopiles. Comparison of the two species{\textquoteright} genomes reveals a rapid expansion and diversification of many protein families associated with plant infection such as hydrolases, ABC transporters, protein toxins, proteinase inhibitors, and, in particular, a superfamily of 700 proteins with similarity to known oomycete avirulence genes.

}, doi = {10.1126/science.1128796}, url = {http://www.sciencemag.org/content/313/5791/1261.abstract}, author = {Tyler, Brett M. and Tripathy, Sucheta and Zhang, Xuemin and Dehal, Paramvir and Jiang, Rays H. Y. and Aerts, Andrea and Arredondo, Felipe D. and Baxter, Laura and Bensasson, Douda and Beynon, Jim L. and Chapman, Jarrod and Damasceno, Cynthia M. B. and Dorrance, Anne E. and Dou, Daolong and Dickerman, Allan W. and Dubchak, Inna L. and Garbelotto, Matteo and Gijzen, Mark and Gordon, Stuart G. and Govers, Francine and Grunwald, Niklaus J. and Huang, Wayne and Ivors, Kelly L. and Jones, Richard W. and Kamoun, Sophien and Krampis, Konstantinos and Lamour, Kurt H. and Lee, Mi-Kyung and McDonald, W. Hayes and Medina, M√>=nica and Meijer, Harold J. G. and Nordberg, Eric K. and Maclean, Donald J. and Ospina-Giraldo, Manuel D. and Morris, Paul F. and Phuntumart, Vipaporn and Putnam, Nicholas H. and Rash, Sam and Rose, Jocelyn K. C. and Sakihama, Yasuko and Salamov, Asaf A. and Savidor, Alon and Scheuring, Chantel F. and Smith, Brian M. and Sobral, Bruno W. S. and Terry, Astrid and Torto-Alalibo, Trudy A. and Win, Joe and Xu, Zhanyou and Zhang, Hongbin and Grigoriev, Igor V. and Rokhsar, Daniel S. and Boore, Jeffrey L.} } @article {867, title = {Phytophthora disease of chestnut}, journal = {Plant Prot.}, volume = {21}, year = {1967}, pages = {383-387}, author = {Uchida, K.} } @article {706, title = {Phytophthora katsurae}, journal = {Crop Knowledge Master}, year = {2006}, month = {22 June 2006}, publisher = {Extension Entomology \& UH-CTAHR Integrated Pest Management Program, University of Hawaii}, address = {Manoa, Hi}, url = {http://www.extento.hawaii.edu/Kbase/crop/Type/p_katsu.htm}, author = {Uchida, JY} } @article {uchida1992phytophthora, title = {Phytophthora fruit and heart rots of coconut in Hawaii}, journal = {Plant disease}, volume = {76}, number = {9}, year = {1992}, pages = {925{\textendash}927}, publisher = {American Phytopathological Society}, abstract = {

Serious fruit and heart rots of coconut were found on the major Hawaiian islands of Kauai, Oahu, Hawaii and Maui. Early symptoms included dark fruit rots and the premature loss of young nuts. A Phytophthora sp. was consistently associated with fruit rots. There was a high association of fruit rots and subsequent heart rot followed by tree death. Fruit and heart rots were reproduced by inoculations. The causal organism resembled P. katsurae, but its identification remains undetermined.

}, doi = {10.1094/PD-76-0925}, url = {http://www.apsnet.org/publications/PlantDisease/BackIssues/Documents/1992Abstracts/PD_76_925.htm}, author = {Uchida, JY and Aragaki, M. and Ooka, J. and Nagata, NM} } @article {ullian_predictability_2000, title = {Predictability begets optimism: A conservation perspective on Port-Orford-cedar and Phytophthora lateralis}, journal = {PLANT DISEASE}, volume = {84}, number = {1}, year = {2000}, pages = {12{\textendash}13}, issn = {0191-2917}, author = {B. Ullian and E.S. Jules} } @article {1324, title = {Phytophthora ramorum infection of coast live oak leaves in Californian forests and its capacity to sporulate in vitro}, journal = {Australasian Plant Pathology}, volume = {37}, year = {2008}, pages = {72-73}, publisher = {Springer Netherlands}, abstract = {

Coast live oak (Quercus agrifolia) is a known host for Phytophthora ramorum, the casual agent of sudden oak death in California, with symptoms expressed as necrotic stem cankers. In the forest, leaves on two saplings in California were found to be infected with P. ramorum and these were associated with infected bay laurel (Umbellularia californica) trees. Coast live oak leaves supported sporulation and produced chlamydospores in vitro. This is the first report to identify foliage of coast live oak as a source of infection of P. ramorum in the forest and its confirmation in in vitro inoculations.

}, issn = {0815-3191}, doi = {10.1071/AP07085}, url = {http://dx.doi.org/10.1071/AP07085}, author = {A.M. Vettraino and H{\"u}berli, D. and Garbelotto, M.} } @proceedings {681, title = {Phytophthora ramorum and Phytophthora kernoviae in England and Wales{\textemdash}Public Consultation and New Programme}, volume = {Gen. Tech. Rep. PSW-GTR-229}, year = {2009}, month = {04/2010}, pages = {6-14}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station.}, address = {Santa Cruz, California}, author = {Keith Walters and Claire Sansford and David Slawson}, editor = {Susan J. Frankel and John T. Kliejunas and Katharine M. Palmieri} } @article {858, title = {The possible origin and relation of Phytophthora katsurae and P. heveae, discovered in a protected natural forest in Taiwan}, journal = {Botanical Studies}, volume = {47}, year = {2006}, pages = {273-277}, abstract = {When a total of 531 soil samples collected from 1976 to 2000 from various locations distributed in every county on the island of Taiwan was assayed, sixteen isolates of Phytophthora katsurae and nine isolates of P. heveae were recovered from three and four counties, respectively. Phytophthora katsurae and P. heveae were isolated from a protected natural forest located atop a hill at Lenhuachih without higher land within the range of vision, suggesting that both species are indigenous to Taiwan. Phytophthora katsurae is distinguished from the similar P. heveae by its verrucose oogonial wall. The number of protrusions produced by the Taiwanese isolates of P. katsurae varied greatly ranging from 2 to 23 per oogonium, indicating the unsteadiness of this taxonomical characteristic. Oogonia produced by isolates of P. katsurae obtained from Hawaii contained very few protrusions. Moreover, most oogonia produced by two of these isolates did not have any protrusions and were indistinguishable from those produced by P. heveae. Results suggest the development of P. heveae directly from P. katsurae by loss of oogonial protrusions. The high level of ITS sequence similarity between P. heveae and P. katsurae in comparison with their relationships to other Phytophthora species tested also support the possibility of the recent development of one species from the other species.}, url = {http://ejournal.sinica.edu.tw/bbas/content/2006/3/Bot473-07/}, author = {Wen-Hsiung, KO and Wang, SY and Ann, PJ} } @article {Werres20011155, title = {Phytophthora ramorum sp. nov., a new pathogen on Rhododendron and Viburnum}, journal = {Mycological Research}, volume = {105}, number = {10}, year = {2001}, pages = {1155 - 1165}, abstract = {

Since 1993, a hitherto unidentified Phytophthora species has been found associated with twig blight disease in Rhododendron and, sporadically, Viburnum. The morphology and growth characteristics of fourteen isolates from Germany and the Netherlands were investigated, together with their breeding system, the internal transcribed spacer (ITS) regions of the ribosomal DNA, amplified fragment length polymorphism (AFLP) fingerprints, and isozyme profiles, which were compared to those of a number of outgroup species. Morphologically the isolates are characterized by abundant production of chlamydospores and elongate, ellipsoid, deciduous sporangia with a short pedicel, in which they resemble P. palmivora. However, sporangia were semi-papillate, chlamydospores were much larger and cardinal temperatures much lower than those of P. palmivora. Oogonia with amphigynous antheridia and plerotic oospores were produced in dual cultures with an A2 mating type strain of P. cryptogea. ITS1 and ITS2 sequences of the unidentified species were closest to those of P. lateralis, but differed in three and eight nucleotides respectively from the latter species. AFLP fingerprints and isozyme patterns of malate dehydrogenase (MDH-2) and malic enzyme (MDHP) showed that the isolates formed a homogeneous group, distinct from all examined outgroup species, including P. lateralis. It was concluded that they represent a new Phytophthora species, described here as P. ramorum sp. nov. In pathogenicity tests all isolates of P. ramorum were pathogenic to Rhododendron.

}, issn = {0953-7562}, doi = {DOI: 10.1016/S0953-7562(08)61986-3}, url = {http://www.sciencedirect.com/science/article/B7XMR-4RS3YCS-4/2/9f9142119aa3952d3dbc8811be4860bb}, author = {Werres, Sabine and Rainer Marwitz and WA Man_In{\textquoteright}t_veld and De Cock, AWAM and Peter J.M. Bonants and De Weerdt, M. and Karin Themann and Elena Ilieva and Robert P. Baayen} } @book {4660, title = {PCR Protocols amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics}, year = {1990}, pages = {315 - 322}, publisher = {Elsevier}, organization = {Elsevier}, isbn = {9780123721808}, doi = {10.1016/B978-0-12-372180-8.50042-1}, url = {https://linkinghub.elsevier.com/retrieve/pii/B9780123721808500421}, author = {White, T.J. and Bruns, T. and Lee, S. and Taylor, J.} } @article {Widmer2010661, title = {Phytophthora kernoviae oospore maturity, germination, and infection}, journal = {Fungal Biology}, volume = {114}, number = {8}, year = {2010}, pages = {661 - 668}, abstract = {

Limited information is known on the basic biology of the recently described Phytophthora kernoviae that produces homothallic oospores. In this study, different P. kernoviae isolates were used to investigate oospore maturity, germination, and infection. All isolates produced oospores in V8 broth at 20{\textdagger}${\i}nfty$C in the dark by 6{\textdagger}d. Oospores also formed at 10 and 15{\textdagger}${\i}nfty$C, but did not form at 25 and 28{\textdagger}${\i}nfty$C. Continuous light inhibited oospore production of some isolates but had no negative effect on others. Maturation time of the oospores, as noted by germination and staining with tetrazolium bromide, was not much different among the isolates between 2 and 14 weeks. Oospore germination was optimal at 18 and 20{\textdagger}${\i}nfty$C, and did not occur at 5, 25, and 30{\textdagger}${\i}nfty$C. Oospore germination under continuous light was higher than in the dark, but individual isolates showed variable results. Rhododendron leaf disks inoculated with oospores and maintained in the dark at 20{\textdagger}${\i}nfty$C were necrotic after 1 week, while those kept under continuous light did not develop necrosis. The percentage of leaf disks infected with P. kernoviae was lower in the leaves exposed to continuous light (40{\textdagger}\%) compared to those kept in the dark (100{\textdagger}\%).

}, keywords = {Viability stain}, issn = {1878-6146}, doi = {DOI: 10.1016/j.funbio.2010.06.001}, url = {http://www.sciencedirect.com/science/article/B9879-508K88P-1/2/e35155432b3146cdabc05226a599fa75}, author = {Timothy L. Widmer} } @book {266, title = {Phytophthora cinnamomi and the diseases it causes}, series = {Amer. Phytopathol. Soc. Monogr}, volume = {10}, year = {1980}, pages = {1-96}, publisher = {American Phytopathological Society}, organization = {American Phytopathological Society}, address = {St. Paul, Minn.}, author = {Zentemeyer, G. A.} }