@article {4135, title = {Taxonomy of Phytophthora palmivora on cocoa}, journal = {Transactions of the British Mycological Society}, volume = {72}, year = {1979}, month = {2/1979}, pages = {111 - 143}, abstract = {

Morphological and physiological studies-chromosome type, colony morphology and growth rate on carrot agar, cocoa pod lesion characteristics, morphology and size of sporangia, sporangial pedicels, chlamydospores and sex organs, compatibility type, growth on a synthetic medium, response to Trichoderma, and temperature relations-were made with c. 950 Phytophthora isolates from cocoa (Theobroma cacao L.) attributed to P. palmivora (Butl.) Butl. The survey covered isolates from all the major cocoa growing areas of the world, and included isolates studied by C. H. Gadd and S. F. Ashby in the 1920s.

The majority of the isolates could be assigned to one of three distinct forms, termed S, L and MF4. The S-type is attributed here to P. palmivora, which is redefined. Both L and MF4 are considered to be distinct species of Phytophthora. The L-type could not be identified with any known species and is described here as P. megakarya sp.nov. P. palmivora occurred world-wide on cocoa, whereas P. megakarya was obtained only from West Africa and MF4 only from Central and South America and the West Indies.

Isolates attributed to P. palmivora from other hosts were also examined. Some isolates from rubber, coconut and durian were P. palmivora (S-type). Isolates from pepper comprised a group closely resembling MF4. Isolates from coconut and rubber originally attributed to P. palmivora by S. F. Ashby, C. H. Gadd and E. M. Blackwell comprised a further group, and were also attributed here to P. palmivora, yet were somewhat different morphologically from the S-type on cocoa. It is not clear which of these two types is authentic P. palmivora.

The significance of these results, and the value of the various diagnostic criteria used, is discussed.

}, issn = {00071536}, doi = {10.1016/S0007-1536(79)80015-7}, url = {http://www.sciencedirect.com/science/article/pii/S0007153679800157}, author = {C.M. Brasier and Griffin, M.J.} } @article {4706, title = {Towards a best practice methodology for the detection of Phytophthora species in soils}, journal = {Plant Pathology}, volume = {Early view}, year = {2020}, month = {Nov-07-2020}, abstract = {

The genus Phytophthora contains species that are major pathogens worldwide, affecting a multitude of plant species across agriculture, horticulture, forestry, and natural ecosystems. Here, we concentrate on those species that are dispersed through soil and water, attacking the roots of the plants, causing them to rot and die. The intention of this study was to compare the soil baiting protocol developed by the Centre for Phytophthora Science and Management (CPSM) with two other baiting methods used in Australia. The aim was to demonstrate the effectiveness of each protocol for soil baiting Phytophthora species in different substrates. Three experiments were conducted: the first to test the sensitivity of each method to detect Phytophthora cinnamomi, the second to test the effect of substrate type (sand or loam), and the third to test the detection of species (P. cinnamomi, P. multivora, or P. pseudocryptogea). The specificity of different plant species baits was compared within and between the methods. Substrate type influenced isolation in all methods; however, the CPSM method was superior regardless of substrate, albeit slower than one of the other methods for one substrate. Comparing bait species between the three methods, Quercus ilex was the most attractive bait for P. cinnamomi, particularly in the CPSM method. The choice of protocol affected the isolation associated with each bait type. Overall, the multiple bait system used by CPSM was shown to provide the most sensitive and reliable detection of Phytophthora species from soil samples.

}, issn = {0032-0862}, doi = {10.1111/ppa.13312}, url = {https://bsppjournals.onlinelibrary.wiley.com/doi/abs/10.1111/ppa.13312?af=R}, author = {Burgess, Treena I. and L{\'o}pez-Villamor, {\'a}n and Paap, Trudy and Williams, Briony and Belhaj, Rajah and Crone, Michael and Dunstan, William and Howard, Kay and Hardy, Giles E. St. J.} } @article {doi:10.1094/PHYTO-95-0587, title = {Transmission of Phytophthora ramorum in mixed-evergreen forest in California}, journal = {Phytopathology}, volume = {95}, number = {5}, year = {2005}, pages = {587-596}, doi = {10.1094/PHYTO-95-0587}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-95-0587}, author = {Davidson, Jennifer M. and Wickland, Allison C. and Patterson, Heather A. and Falk, Kristen R. and Rizzo, David M.} } @article {4558, title = {Two Phytophthora species causing decline of wild olive (Olea europaea subsp. europaea var. sylvestris )}, journal = {Plant Pathology}, year = {2016}, month = {Nov-2016}, abstract = {

Since 2009, a severe decline leading to mortality has been observed affecting nearly 5\ ha of a wild olive woodland of high ecological value in Seville, southern Spain. Phytophthora cryptogea and P.\ megasperma were consistently isolated from roots and rhizosphere of trees with symptoms sampled in 2009, 2011 and 2013. The isolates were identified on the basis of colony and reproductive structure morphology as well as temperature{\textendash}growth relationships, and identification was further corroborated by their ITS and β-tubulin sequences. Koch{\textquoteright}s postulates were demonstrated for both species on 1-year-old wild olives. Pathogenicity tests showed that both Phytophthora spp. are highly aggressive pathogens, although temperature{\textendash}growth requirements for each species were distinct. As a consequence, the two species may be active in different seasons and their epidemiology may be differently influenced by global climate change, and they may show their active periods in different climatic scenarios. The climate change models for the Mediterranean Basin forecast a global temperature increase that favours the more thermophilic P.\ cryptogea. The high susceptibility to phytophthora root rot should not be disregarded in olive breeding programmes where wild olive is used as a source of resistance to verticillium wilt.

}, doi = {10.1111/ppa.12649}, url = {https://doi.org/10.1111/ppa.12649 }, author = {Gonz{\'a}lez, M. and P{\'e}rez-Sierra, A. and Serrano, M. S. and Sanchez, M. E.} } @article {hansen1989testing, title = {Testing Port-Orford-cedar for resistance to Phytophthora.}, journal = {Plant Disease}, volume = {73}, number = {10}, year = {1989}, pages = {791{\textendash}794}, issn = {0191-2917}, author = {Hansen, E.M. and P.B. Hamm and L.F. Roth} } @article {Hansen1986557, title = {The taxonomic structure of Phytophthora megasperma: Evidence for emerging biological species groups}, journal = {Transactions of the British Mycological Society}, volume = {87}, number = {4}, year = {1986}, pages = {557 - 573}, abstract = {

Nomenclatural uncertainty surrounds P. megasperma as various authors, working with limited groups of isolates, offer their interpretations of this species based on pathology, morphology, or cytology. We compared 93 isolates, including many described by others, for classical morphological features, growth behaviour and appearance, electrophoretic pattern of total proteins, chromosome number and nuclear DNA content. Nine distinct sub-groups were distinguished. While most groups could be distinguished by each of the criteria, protein electrophoresis was the most sensitive. The groups included: ALF, pathogenic to alfalfa, n = 12{\textendash}15; SOY, pathogenic to soybean, n = 12{\textendash}15; CLO, pathogenic to clover, n = 11{\textendash}15; DF, pathogenic to Douglas fir, n = 17{\textendash}24; AC, isolated from rosaceous fruit trees; and BHR, a major group obtained from a broad range of hosts. The last two groups, distinguished primarily by protein pattern, comprised at least four karyotypes: KI, n = 12{\textendash}17; KII, n = 15{\textendash}23; KIII, n = 22{\textendash}28; and KIV, n= 26{\textendash}34. All four karyotypes occur within the BHR protein group, suggesting a polyploid series within a closely related genotype.

Two broad lines of evolution are hypothesized, a legume line comprising ALF, SOY, CLO, and perhaps DF isolates, and a Broad Host Range line of AC and BHR isolates. Sub-groups within each line may represent emerging biological species, isolated by host specificity or karyotype. Taxonomic designation for the various groups must await confirmation of the hypothesis by demonstration of the extent of barriers to gene flow between the groups.

}, issn = {0007-1536}, doi = {10.1016/S0007-1536(86)80097-3}, url = {http://www.sciencedirect.com/science/article/pii/S0007153686800973}, author = {Hansen, E.M. and C.M. Brasier and D.S. Shaw and P.B. Hamm} } @article {4470, title = {Temporal metabolic profiling of the Quercus suber - Phytophthora cinnamomi system by middle-infrared spectroscopy}, journal = {Forest Pathology}, volume = {46}, year = {2016}, month = {Jan-04-2016}, pages = {122 - 133}, abstract = {

The oomycete Phytophthora cinnamomi is an aggressive plant pathogen, detrimental to many ecosystems including cork oak (Quercus suber) stands, and can inflict great losses in one of the greatest {\textquoteleft}hotspots{\textquoteright} for biodiversity in the world. Here, we applied Fourier transform-infrared (FT-IR) spectroscopy combined with chemometrics to disclose the metabolic patterns of cork oak roots and P.\ cinnamomi mycelium during the early hours of the interaction. As early as 2\ h post-inoculation (hpi), cork oak roots showed altered metabolic patterns with significant variations for regions associated with carbohydrate, glycoconjugate and lipid groups when compared to mock-inoculated plants. These variations were further extended at 8\ hpi. Surprisingly, at 16\ hpi, the metabolic changes in inoculated and mock-inoculated plants were similar, and at 24\ hpi, the metabolic patterns of the regions mentioned above were inverted when compared to samples collected at 8\ hpi. Principal component analysis of the FT-IR spectra confirmed that the metabolic patterns of inoculated cork oak roots could be readily distinguished from those of mock-inoculated plants at 2, 8 and 24\ hpi, but not at 16\ hpi. FT-IR spectral analysis from mycelium of P.\ cinnamomi exposed to cork oak root exudates revealed contrasting variations for regions associated with protein groups at 16 and 24\ h post-exposure (hpe), whereas carbohydrate and glycoconjugate groups varied mainly at 24\ hpe. Our results revealed early alterations in the metabolic patterns of the host plant when interacting with the biotrophic pathogen. In addition, the FT-IR technique can be successfully applied to discriminate infected cork oak plants from mock-inoculated plants, although these differences were dynamic with time. To a lesser extent, the metabolic patterns of P.\ cinnamomi were also altered when exposed to cork oak root exudates.

}, doi = {10.1111/efp.2016.46.issue-210.1111/efp.12229}, url = {http://doi.wiley.com/10.1111/efp.2016.46.issue-2http://doi.wiley.com/10.1111/efp.12229http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fefp.12229}, author = {Hardoim, P. R. and Guerra, R. and Rosa da Costa, A. M. and Serrano, M. S. and Sanchez, M. E. and Coelho, A. C.}, editor = {Stenlid, J.} } @article {3973, title = {Three new species of Phytophthora from European oak forests}, journal = {Mycological Research}, volume = {106}, year = {2002}, month = {4/2002}, pages = {397 - 411}, abstract = {

In several studies of oak decline in Europe, one semi-papillate (Phytophthora psychrophila sp. nov.) and two nonpapillate homothallic Phytophthora species (P. europaea sp. nov. and P. uliginosa sp. nov.) were isolated, together with other Phytophthora species, from rhizosphere soil samples which could not be assigned to existing taxa. P. psychrophila differs from other semi-papillate species of Waterhouse{\textquoteright}s morphological Group IV, like P. ilicis and P. hibernalis, by its uniform, dome-shaped and cotton wool-like colony growth pattern on V8 juice agar and malt extract agar, the occurrence of sympodially branched primary hyphae, the high variation in size and shape of the sporangia, shorter pedicels, lower optimum temperature for growth, and internal transcribed spacer (ITS) sequences. P. europaea is distinguished from related nonpapillate Group V and VI species, namely P. fragariae, P. cambivora, and the {\textquoteright}alder phytophthora{\textquoteright}, by producing oogonia with tapered bases, irregular walls and exclusively paragynous antheridia, its cardinal temperatures for growth, and ITS sequences. P. uliginosa differs from related Group V and VI species by its large oogonia with exclusively paragynous antheridia, the predominant occurrence of ellipsoid sporangia with markedly wide exit pores, its slow growth, low cardinal temperatures, its colony growth patterns, and ITS sequences. P. uliginosa is separated from P. europaea by its larger oospores without tapering bases, lower cardinal temperatures and growth rates, different colony growth patterns, and greater aggressiveness on Q. robur.

}, issn = {09537562}, doi = {10.1017/S0953756202005622}, author = {Thomas Jung and Hansen, Everett M. and Winton, Lori and O{\ss}wald, Wolfgang and Delatour, Claude} } @article {4079, title = {Two new Phytophthora species from South African Eucalyptus plantations}, journal = {Mycological Research}, volume = {111}, year = {2007}, month = {11/2007}, pages = {1321 - 1338}, abstract = {

A recent study to determine the cause of collar and root rot disease outbreaks of cold tolerant Eucalyptus species in South Africa resulted in the isolation of two putative new Phytophthora species. Based on phylogenetic comparisons using the ITS and β-tubulin gene regions, these species were shown to be distinct from known species. These differences were also supported by robust morphological characteristics. The names, Phytophthora frigida sp. nov. and Phytophthora alticola sp. nov. are thus provided for these taxa, which are phylogenetically closely related to species within the ITS clade 2 (P. citricola, P. tropicali and P.multivesiculata) and 4 (P. arecae and P. megakarya), respectively. Phytophthora frigida is heterothallic, and produces stellate to rosaceous growth patterns on growth medium, corraloid hyphae, sporangia with a variety of distorted shapes and has the ability to grow at low temperatures. Phytophthora alticola is homothallic and has a slower growth rate in culture. Both P. frigida and P. alticola are pathogenic to Eucalyptus dunnii. In pathogenicity tests, they were, however, less pathogenic than P. cinnamomi, which is a well-known pathogen of Eucalyptus in South Africa.

}, issn = {09537562}, doi = {10.1016/j.mycres.2007.08.011}, url = {http://www.sciencedirect.com/science/article/pii/S0953756207001955}, author = {Maseko, Bongani and Burgess, Treena I. and Coutinho, Teresa A. and Michael J. Wingfield} } @article {4658, title = {Taxonomic structure of Phytophthora cryptogea and P. drechsleri based on isozyme and mitochondrial DNA analyses}, journal = {Mycological Research}, volume = {95}, year = {1991}, month = {Jan-01-1991}, pages = {31 - 48}, abstract = {

Intra- and interspecific isozyme variation was evaluated for 123 isolates assigned to either Phytophthora cryptogea or P. drechsleri, and compared with that of 15 isolates of P. erythroseptica and 11 isolates of P. lateralis. Isolates of P. cryptogea and P. drechsleri were from worldwide sources and displayed a high degree of variability. The majority of these isolates were subsequently divided into ten distinct groups based on numerical analysis of 24 putative enzyme loci. None of the enzyme loci were monomorphic for all ten groups. Analysis of mitochondrial (mt) DNA restriction fragment length polymorphisms of selected isolates from each isozyme group supported the isozyme data. Differences in morphological features of the ten isozyme groups of P. cryptogea and P. drechsleri were not sufficiently distinct to readily distinguish between them. Isozyme analysis of P. erythroseptica revealed that it is a uniform and distinct taxon. The isolates of P. lateralis also formed a homogeneous and discrete group. An interspecific comparison revealed that the variation among the ten isozyme groups of P. cryptogea and P. drechsleri was as great as that observed among P. cinnamomi, P. cambivora, P. lateralis, P. erythroseptica and P. richardiae. The combined results of isozyme and mtDNA analysis indicate that there are at least seven distinct molecular species represented by the 123 isolates of P. cryptogea and P. drechsleri evaluated in this study.

}, issn = {09537562}, doi = {10.1016/S0953-7562(09)81359-2}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0953756209813592}, author = {Mills, Scott D. and F{\"o}rster, Helga and Coffey, Michael D.} } @article {Mills199131, title = {Taxonomic structure of Phytophthora cryptogea and P. drechsleri based on isozyme and mitochondrial DNA analyses}, journal = {Mycological Research}, volume = {95}, number = {1}, year = {1991}, pages = {31 - 48}, abstract = {

Intra- and interspecific isozyme variation was evaluated for 123 isolates assigned to either Phytophthora cryptogea or P. drechsleri, and compared with that of 15 isolates of P. erythroseptica and 11 isolates of P. lateralis. Isolates of P. cryptogea and P. drechsleri were from worldwide sources and displayed a high degree of variability. The majority of these isolates were subsequently divided into ten distinct groups based on numerical analysis of 24 putative enzyme loci. None of the enzyme loci were monomorphic for all ten groups. Analysis of mitochondrial (mt) DNA restriction fragment length polymorphisms of selected isolates from each isozyme group supported the isozyme data. Differences in morphological features of the ten isozyme groups of P. cryptogea and P. drechsleri were not sufficiently distinct to readily distinguish between them. Isozyme analysis of P. erythroseptica revealed that it is a uniform and distinct taxon. The isolates of P. lateralis also formed a homogeneous and discrete group. An interspecific comparison revealed that the variation among the ten isozyme groups of P. cryptogea and P. drechsleri was as great as that observed among P. cinnamomi, P. cambivora, P. lateralis, P. erythroseptica and P. richardiae. The combined results of isozyme and mtDNA analysis indicate that there are at least seven distinct molecular species represented by the 123 isolates of P. cryptogea and P. drechsleri evaluated in this study.

}, issn = {0953-7562}, doi = {DOI: 10.1016/S0953-7562(09)81359-2}, url = {http://www.sciencedirect.com/science/article/B7XMR-4VN66D4-6/2/554a78ec5ee059d8f8ca3d1ba95638fd}, author = {Scott D. Mills and Helga F{\"o}rster and Michael D. Coffey} } @article {EFP:EFP711, title = {A twig blight of understorey European beech (Fagus sylvatica) caused by soilborne Phytophthora spp.}, journal = {Forest Pathology}, volume = {41}, number = {6}, year = {2011}, pages = {493{\textendash}500}, publisher = {Blackwell Publishing Ltd}, abstract = {

During and after prolonged periods of rainfall in late spring, blighted young twigs of European beech (Fagus sylvatica) were frequently observed in several beech stands in south-western and southern Germany. Long and short shoots of young understorey trees or lower branches up to 1.5 m above the soil level were affected. Symptoms also occurred regularly on twigs in heights up to 2 m and more above the ground. Necroses usually expanded within the current year{\textquoteright}s tissue and often also reached into the previous year{\textquoteright}s wood. Ponding rain water in the stands or along forest roads or open soil seemed to promote the disease. Of a total of 54 symptomatic twigs collected in four stands, 37 revealed Phytophthora isolates, of which 33 were P. plurivora and four were P. cambivora. Both species caused extensive lesions on beech twigs in laboratory pathogenicity tests. Patterns of the disease indicated that these pathogens, generally considered soilborne species, in most cases are transmitted from the soil to above-ground parts of the trees via rain splash. In larger heights, however, other vectors such as snails might be responsible for transmission. Although Phytophthora spp. are well known as causal agents of seedling blight as well as root and cambium rot and aerial bleeding cankers of mature beech, to our knowledge this is the first report of a twig blight in beech associated with soilborne Phytophthora spp. In particular in periods of high precipitation, this disease might pose an additional threat to Central European beech forests, especially endangering the success of artificial and natural regeneration of beech in affected stands.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00711.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00711.x}, author = {Nechwatal, J. and Hahn, J. and Schönborn, A. and Schmitz, G.} } @article {4290, title = {Temporal Epidemiology of Sudden Oak Death in Oregon}, journal = {Phytopathology}, year = {2015}, month = {Feb-04-2016}, pages = {150414124631002}, abstract = {

An effort to eradicate Phytophthora ramorum , causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter precipitation two years before detection, and infestation size the year prior. Infestation size was best modeled by infestation size and spring precipitation the year prior. In our interpretation, there is a two year delay between the introduction of inoculum and onset of mortality for a majority of sites. The year-long gap in between allows ample time for the production of inoculum contributing to the spread of P. ramorum. This is supported by epidemic development following changes in eradication protocols precipitated by an outbreak in 2011, attributable to a 2009 treatment delay and an uncharacteristically wet spring in 2010. Post-eradication, we have observed an increase in the total area of new outbreaks and increased frequency in dispersal distances greater than 4 km. While the eradication program has not eliminated P. ramorum from Oregon forests it has likely moderated this epidemic, emphasizing the need for prompt treatment of future invasive forest pathogens.

}, issn = {0031-949X}, doi = {10.1094/PHYTO-12-14-0348-FI}, url = {http://apsjournals.apsnet.org/doi/10.1094/PHYTO-12-14-0348-FI}, author = {Peterson, Ebba and Hansen, Everett and Kanaskie, Alan} } @article {PPA:PPA2463, title = {Two novel and potentially endemic species of Phytophthora associated with episodic dieback of Kwongan vegetation in the south-west of Western Australia}, journal = {Plant Pathology}, volume = {60}, year = {2011}, pages = {1055{\textendash}1068}, publisher = {Blackwell Publishing Ltd}, abstract = {

Two novel homothallic species of Phytophthora causing dieback of Kwongan vegetation in south-west Western Australia are described here as Phytophthora arenaria sp. nov. and Phytophthora constricta sp. nov. DNA sequencing of the ITS rDNA and cox1 gene confirmed that P.\ arenaria and P.\ constricta are unique species residing in ITS clades 4 and 9, respectively. Phytophthora arenaria has been isolated from vegetation occurring on the northern sandplains which are warmer and drier than the southern sandplains from which P.\ constricta has been predominantly isolated, and both species appear morphologically and physiologically well adapted to the ecosystems in which they occur. Both species have been associated mainly with dead and dying Banksia species and the pathogenicity of both P.\ arenaria and P.\ constricta to Banksia attenuata was confirmed in this study. The combination of unique DNA sequences, including considerable variation in cox1 sequence data, thick oospore walls and physiological characteristics that appear to be adaptations favouring survival in the harsh Kwongan ecosystem suggest that these species may be endemic to Western Australia.

}, keywords = {Mediterranean climate, natural ecosystems, pathogens, phylogeny, Phytophthora arenaria, Phytophthora constricta}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2011.02463.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2011.02463.x}, author = {Rea, A. J. and Burgess, T. I. and Hardy, G. E. St J. and Stukely, M. J. C. and T. Jung} } @article {4033, title = {A taxonomic re-evaluation reveals that Phytophthora cinnamomi and P.~cinnamomi var. parvispora are separate species}, journal = {Forest Pathology}, year = {2013}, month = {07/2013}, pages = {n/a - n/a}, abstract = {

Between 2008 and 2011, severe dieback associated with root and collar rot was reported on Arbutus unedo in several sites in Sardinia, Italy. Isolations from infected tissues and rhizosphere soil samples consistently yielded a Phytophthora species. It was initially identified as Phytophthora cinnamomi var. parvispora Kr{\"o}ber and Marwitz by comparing morphological features with the original description and the internal transcribed spacer (ITS) sequences with those present in GenBank. A multigene phylogeny based on DNA sequence data from two nuclear (ITS and β-tubulin) and two mitochondrial (cox1 and cox2) gene regions combined with extensive morphological and physiological properties of these isolates, including the ex-type culture of P.\ cinnamomi var. parvispora, demonstrates that this taxon is unique and it is redesignated here as Phytophthora parvispora sp. nov. Although morphologically similar to P.\ cinnamomi, P.\ parvispora differs by its smaller-sized sporangia, chlamydospores, oogonia and oospores, higher oospore wall index, single-celled antheridia, higher minimum and maximum temperatures for growth and faster growth at optimum temperature. In the phylogeny, P.\ parvispora falls within Phytophthora ITS clade 7a, grouped in a well-supported clade sister to P.\ cinnamomi. In pathogenicity tests, P.\ parvispora and P.\ cinnamomi were equally aggressive towards A.\ unedo seedlings. The possible geographic origin of P.\ parvispora is also discussed.

}, doi = {10.1111/efp.12064}, url = {http://onlinelibrary.wiley.com/doi/10.1111/efp.12064/abstract}, author = {Scanu, B. and Hunter, G. C. and Linaldeddu, B. T. and Franceschini, A. and Maddau, L. and T. Jung and Denman, S.}, editor = {Andrea, V.} } @article {1132, title = {A test system to quantify inoculum in runoff from Phytophthora ramorum-infected plant roots}, journal = {Phytopathology}, volume = {101}, year = {2011}, pages = {1457-1464}, abstract = {

Foliar hosts of Phytophthora ramorum are often susceptible to root infection but the epidemiological significance of such infections is unknown. A standardized test system was developed to quantify inoculum in runoff from root-infected Viburnum tinus {\textquoteleft}Spring Bouquet{\textquoteright} or Rhododendron {\textquoteleft}Cunningham{\textquoteright}s White{\textquoteright} cuttings. Cuttings of both species gave off a maximum amount of inoculum 1 to 3 weeks after inoculation. The greatest amount of inoculum was recovered from Viburnum roots that were 48 to 70 days old at the time of inoculation, or roots incubated at 15 to 20{\textdegree}C rather than 25{\textdegree}C. Inoculum in runoff from inoculated Viburnum roots was similar for four different isolates of P. ramorum representing both the NA1 and EU1 lineages. When Rhododendron cuttings were inoculated with P. ramorum, P. citricola, or P. cactorum, inoculum of all three pathogens was recovered from runoff, with the highest amount recovered from plants inoculated with P. citricola, followed by the other two. Compared with the other two pathogens, P. ramorum colonized root tissue to a smaller extent. The epidemiology of root infection by P. ramorum is important in itself but the assay might lend itself for use in risk analysis for root infection of other plant species and evaluation of control measures, and also shed light on other root-infecting Phytophthora spp.

}, doi = {10.1094/PHYTO-09-10-0260}, url = {http://dx.doi.org/10.1094/PHYTO-09-10-0260}, author = {Shishkoff, Nina} } @article {4016, title = {A TaqMan real-time PCR assay for the detection of Phytophthora {\textquoteleft}taxon Agathis{\textquoteright} in soil, pathogen of Kauri in New Zealand}, journal = {Forest Pathology}, volume = {43}, year = {2013}, month = {04/2013}, pages = {324{\textendash}330}, abstract = {

Kauri Agathis australis, an iconic tree of New Zealand, is under threat from an introduced disease-causing pathogen provisionally named Phytophthora {\textquoteleft}taxon Agathis{\textquoteright} (referred to as PTA). This soilborne, Pythiaceous species belongs to the Chromista and causes a collar rot resulting in yellowing of the foliage and thinning of the canopy, which eventually causes death of the infected tree. The management and containment of this pathogen requires rapid and reliable detection in the soil. The current method for soil detection utilizes a soil bioassay involving lupin baits and soil flooding in a process that takes between ten and twenty days. We describe a real-time PCR assay based on TaqMan chemistry for the specific detection of PTA, which targets the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA. This TaqMan real-time PCR assay could be used with DNA extracted directly from bulk soil samples to enable rapid quantification of PTA within soil. The detection limit was 2\ fg of PTA DNA from pure culture, or 20\ fg in the presence of DNA extracted from soil. The assay was validated using soil samples taken from a PTA-infested site and soil spiked with a known concentration of oospores. We conclude that the TaqMan real-time PCR assay offers a more time-efficient method for detection of PTA in soil than existing methods.

}, doi = {10.1111/efp.12034}, url = {http://onlinelibrary.wiley.com/doi/10.1111/efp.12034/abstract}, author = {Than, D. J. and Hughes, K. J. D. and Boonhan, N. and Tomlinson, J. A. and Woodhall, J. W. and Bellgard, S.E.}, editor = {Andrea, V.} } @article {4048, title = {Taxonomy in Phytophthora}, journal = {Phytopathology}, volume = {60}, year = {1970}, month = {1970}, pages = {1141}, issn = {0031949X}, doi = {10.1094/Phyto-60-1141}, author = {Waterhouse, Grace M.} } @article {4310, title = {A taxonomic revision of Phytophthora Clade 5 including two new species, Phytophthora agathidicida and P. cocois}, journal = {Phytotaxa}, volume = {205}, year = {2015}, month = {10/2015}, pages = {21}, abstract = {

Phytophthora Clade 5 is a very poorly studied group of species of oomycete chromists, consisting of only two known species P. castaneae (= P. katsurae, nom. illegit.) and P. heveae with most isolates from East Asia and the Pacific Islands. However, isolates of two important disease-causing chromists in Clade 5, one of kauri (Agathis australis) in New Zealand, the other of coconut (Cocos nucifera) in Hawaii, poorly match the current species descriptions. To verify whether these isolates belong to separate species a detailed morphological study and phylogenetic analysis consisting of eight genetic loci was conducted. On the basis of genetic and morphological differences and host specificity, we present the formal description of two new species in Clade 5, Phytophthora agathidicida sp. nov. and Phytophthora cocois sp. nov. To clarify the typification of the other Clade 5 species, an authentic ex-holotype culture of Phytophthora castaneae is designated and P. heveae is lectotypified and epitypified.

}, issn = {1179-3155}, doi = {http://dx.doi.org/10.11646/phytotaxa.205.1.2}, url = {http://biotaxa.org/Phytotaxa/article/view/phytotaxa.205.1.2}, author = {Weir, B. S. and Paderes, E. P. and Anand, N. and Uchida, J. Y. and Pennycook, S. R. and Bellgard, S. E. and Beever, R. E.} }