@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 {261, title = {The occurrence of Phytophthora cinnamomi in the soil under pine stands in the southeast.}, journal = {Phytopathology}, volume = {41}, year = {1951}, pages = {742-746}, author = {Campbell, W.A.} } @article {campbell1954littleleaf, title = {Littleleaf disease of shortleaf and loblolly pines}, number = {Circular no. 940.}, year = {1954}, pages = {41 pages}, publisher = {USDA Forest Service}, address = {Washington, DC}, author = {Campbell, W.A. and Copeland, O.L.} } @article {delCastilloM√∫nera2012, title = {Developing a taxonomic identification system of Phytophthora species based on microsatellites}, journal = {Revista Iberoamericana de Micologia}, volume = {In press}, year = {2012}, pages = {-}, abstract = {

Phytophthora spp. is the most important genus of the Oomycete plant pathogens. Nowadays, there are 117 described species in this genus, most of them being primary invaders of plant tissues. The different species are causal agents of diseases in a wide range of crops and plants in natural environments. In order to develop control strategies against Phytophthora spp., it is important to know the biology, ecology and evolutionary processes of these important pathogens.

}, issn = {1130-1406}, doi = {10.1016/j.riam.2012.11.002}, url = {http://www.sciencedirect.com/science/article/pii/S1130140612001106}, author = {J. del Castillo-M{\'u}nera and M. C{\'a}rdenas and A. Pinz{\'o}n and A. Casta{\~n}eda and A.J. Bernal and S. Restrepo} } @article {4472, title = {Metabarcoding and development of new Real-time specific assays reveal Phytophthora species diversity in Holm Oak forests in eastern Spain}, journal = {Plant Pathology}, volume = {66}, year = {2017}, month = {Jan-04-2016}, pages = {115{\textendash}123}, abstract = {

The evergreen holm oaks (Quercus ilex subsp. ilex and Q.\ ilex subsp. ballota) are the most representative tree species in the Iberian peninsula and the main tree species in oak-rangeland ecosystems (dehesas). Oak decline in western, central and southern parts of Spain has been associated with root rot caused by Phytophthora cinnamomi for decades. However, Phytophthora species such as P.\ quercina and P.\ psychrophila have recently been found associated with Quercus decline in eastern Spain where calcareous soils are predominant. Soil and root samples from two Quercus forests presenting decline symptoms in two different geographical areas in eastern Spain (Carrascar de la Font Roja and Vallivana) were analysed by amplicon pyrosequencing. Metabarcoding analysis showed Phytophthora species diversity, and revealed that an uncultured Phytophthora taxon, named provisionally Phytophthora taxon ballota, was the predominant species in both areas. In addition, a real-time PCR assay, based on the pyrosequencing results, was developed for the detection of this uncultured Phytophthora taxon, and also for the detection of P.\ quercina. TaqMan assays were tested on soil and root samples, and on Phytophthora pure cultures. The new assays showed high specificity and were consistent with metabarcoding results. A new real-time PCR protocol is proposed to evaluate the implication of different Phytophthora spp. in oak decline in eastern Spain.

}, doi = {10.1111/ppa.12541}, url = {http://doi.wiley.com/10.1111/ppa.12541}, author = {Catal{\`a}, S. and Berbegal, M. and P{\'e}rez-Sierra, A. and Abad-Campos, P.} } @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 {4031, title = {Change of Mating Type in an EU1 Lineage Isolate of Phytophthora ramorum}, journal = {Journal of Phytopathology}, year = {2013}, month = {07/2013}, pages = {n/a - n/a}, abstract = {

All Phytophthora ramorum EU1 lineage isolates tested are of A1 mating type, except for three rare isolates from 2002 to 2003 from Belgium, which were originally assigned the A2 mating type. In one of these isolates (2338), a switch from A2 to A1 mating type was observed in 2006. This observation initiated a larger study in which all cultures and subcultures of the original three EU1 A2 isolates, maintained in three laboratories under different storage conditions, were checked for mating type change. The A2 to A1 mating type switch was observed in four of seven independently maintained isolates that were derived from isolate 2338 in two laboratories, using different transfer regimes and storage conditions. Following the mating type switch to A1 in these four derived isolates, no reversion back to A2 mating was observed, even after up to 5\ years of additional isolate maintenance and several more subculturing events. The three other isolates that were derived from isolate 2338 as well as the other EU1 A2 isolates collected in 2002 and 2003 and stored in the same conditions did not display such mating type change. The potential causes of the mating type conversions as well as their epidemiological implications are discussed.

}, doi = {10.1111/jph.12150}, url = {http://onlinelibrary.wiley.com/doi/10.1111/jph.12150/abstract}, author = {Chandelier, Anne and Heungens, Kurt and Werres, Sabine} } @article {375, title = {Effect of temperature and bacteria on sporulation of Phytophthora alni in river water}, journal = {Commun Agric Appl Biol Sci.}, volume = {71}, year = {2006}, pages = {873{\textendash}80}, url = {http://www.ncbi.nlm.nih.gov/pubmed/17390834}, author = {Chandelier, A. and Abras, S. and Laurent, F. and Debruxelles, N. and Cavelier, M.} } @article {4455, title = {Assessment of inoculation methods for screening black alder resistance to Phytophthora~{\texttimes} alni}, journal = {Plant Pathology}, volume = {65}, year = {2016}, month = {Jan-04-2016}, pages = {441 - 450}, abstract = {

Identification of resistance to Phytophthora\ {\texttimes}alni could provide the basis for a management strategy against alder decline in riparian ecosystems in Europe. This study aimed to test methods to evaluate the resistance of riparian alders to the disease, and to screen alder genotypes for resistance. Phytophthora\ {\texttimes}alni isolates were compared for their aggressiveness (lesion length on stem) and sporulation capacity (sporangia). While no difference in lesion lengths was found between isolates, sporangia production was dependent on isolate, highlighting the need for careful selection of isolates used for zoospore inoculation methods. Inoculation tests carried out at different periods of the year revealed a seasonal change in susceptibility to the disease, with the period from June to September being the most efficient for inoculation tests. Stem-wounded inoculations, carried out on excised shoots, were unreliable for evaluating the level of resistance of alder genotypes to P.\ {\texttimes}alni infection, with divergent results between two successive years or between two inoculation periods during the same year. In contrast, a method that mimics the natural conditions of infection, based on flooding of rooted cuttings in artificially infected river water, was found promising. Another method, based on the inoculation of foliated terminal shoots with zoospore suspensions, was found to be repeatable and could be used for high-throughput analyses. Altogether, the results show a continuous resistance response from highly susceptible to moderately resistant genotypes. This suggests that breeding might be a useful strategy to manage alder decline caused by P.\ {\texttimes}alni.

}, doi = {10.1111/ppa.2016.65.issue-310.1111/ppa.12418}, url = {http://doi.wiley.com/10.1111/ppa.2016.65.issue-3http://doi.wiley.com/10.1111/ppa.12418http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fppa.12418}, author = {Chandelier, A. and Husson, C. and Druart, P. and Mar{\c c}ais, B.} } @article {chastagner1995symptoms, title = {Symptoms and Phytophthora spp. associated with root rot and stem canker of noble fir Christmas trees in the Pacific Northwest}, journal = {Plant disease}, volume = {79}, number = {3}, year = {1995}, pages = {290{\textendash}293}, publisher = {American Phytopathological Society}, keywords = {Abies procera, America, Artificial forest stand, Coniferales, epidemiology, Field study, Fungi, Gymnospermae, Host agent relation, infection, Mycosis, North America, Oregon, Phycomycetes, Phytophthora, Plant pathogen, Root, Softwood forest tree, Spermatophyta, Stem, Symptomatology, Thallophyta, United States, Washington}, issn = {0191-2917}, doi = {DOI: 10.1094/PD-79-0290}, url = {http://www.apsnet.org/publications/PlantDisease/BackIssues/Documents/1995Abstracts/PD_79_290.htm}, author = {Chastagner, G.A. and P.B. Hamm and Riley, K.L.} } @article {4012, title = {Membrane-based oligonucleotide array developed from multiple markers for the detection of many Phytophthora species}, journal = {Phytopathology}, volume = {103}, year = {2013}, month = {01/2013}, pages = {43 - 54}, abstract = {

Most Phytophthora spp. are destructive plant pathogens; therefore, effective monitoring and accurate early detection are important means of preventing potential epidemics and outbreaks of diseases. In the current study, a membrane-based oligonucleotide array was developed that can detect Phytophthora spp. reliably using three DNA regions; namely, the internal transcribed spacer (ITS), the 5' end of cytochrome c oxidase 1 gene (cox1), and the intergenic region between cytochrome c oxidase 2 gene (cox2) and cox1 (cox2-1 spacer). Each sequence data set contained ≈250 sequences representing 98 described and 15 undescribed species of Phytophthora. The array was validated with 143 pure cultures and 35 field samples. Together, nonrejected oligonucleotides from all three markers have the ability to reliably detect 82 described and 8 undescribed Phytophthora spp., including several quarantine or regulated pathogens such as Phytophthora ramorum. Our results showed that a DNA array containing signature oligonucleotides designed from multiple genomic regions provided robustness and redundancy for the detection and differentiation of closely related taxon groups. This array has the potential to be used as a routine diagnostic tool for Phytophthora spp. from complex environmental samples without the need for extensive growth of cultures.

}, issn = {0031-949X}, doi = {10.1094/PHYTO-04-12-0092-R}, author = {Chen, Wen and Djama, Zeinab Robleh and Michael D. Coffey and Martin, Frank N. and Bilodeau, Guillaume J. and Radmer, Lorien and Denton, Geoff and L{\'e}vesque, C. Andr{\'e}} } @article {EFP:EFP717, title = {Detection of mRNA by reverse-transcription PCR as an indicator of viability in Phytophthora ramorum}, journal = {Forest Pathology}, volume = {42}, number = {1}, year = {2012}, pages = {14{\textendash}21}, publisher = {Blackwell Publishing Ltd}, abstract = {

In the last few decades, the use of molecular tools has greatly improved the efficiency of plant disease diagnosis. However, one of the major setbacks of most molecular diagnostic approaches is their inability to differentiate between dead and viable pathogens. We propose a new strategy for the detection of plant pathogens, based on the use of mRNA as a viability marker, on the basis that mRNA degradation in dead cells is significantly more rapid than that of DNA. A real-time reverse-transcription PCR (RT-PCR) assay targeting the mRNA of the subunit I of the cytochrome oxidase gene was designed for Phytophthora ramorum, the causal agent of sudden oak death and ramorum blight. In controlled laboratory tests, the developed RT-PCR assay did not detect the target mRNA a week after the pathogen had been killed by rapid lyophilization, while DNA of the pathogen could still be detected 3\ months after the pathogen had died. The RT-PCR assay was then compared with a traditional culturing approach using PARP selective medium and two nested real-time PCR techniques on symptomatic California bay laurel leaves. Samples were either collected in three different sites in July, or in the same site but in three different seasons. Overall, RT-PCR results showed less positive samples than DNA-based nested PCR techniques (p\ \<\ 0.0001), but more than culturing (p\ =\ 0.017). Nested PCR-positive but RT-PCR-negative samples may not be viable. On the other hand, RT-PCR-positive but culture-negative samples may be viable but dormant. A comparative analysis of the results indicated that RT-PCR and culturing provide comparable results when climatic conditions are optimal for the pathogen, but RT-PCR may be the most accurate approach to determine pathogen viability when climatic conditions are less than optimal for the pathogen.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00717.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00717.x}, author = {Chimento, A. and Cacciola, S. O. and Garbelotto, M.} } @article {4480, title = {First report of Phytophthora gonapodyides causing stem canker on European beech (Fagus sylvatica) in Southern Sweden}, journal = {Plant Disease}, year = {2016}, month = {Nov-05-2017}, abstract = {

Since 2010, extensive crown transparency of European beech (Fagus sylvatica) has been recorded in Southern Sweden, with P. cambivora, P. plurivora, and P. cactorum as well as associated climatic triggers believed to be the major factors involved. In 2015, a different Phytophthora species was isolated from three F. sylvatica trees showing characteristic bleeding canker symptoms in Pildammsparken in Malm{\"o}, Sweden. Small sections of inner phloem were dissected at the interface between necrotic and healthy tissue, directly plated onto PAR(PH)-V8 Selective medium containing 0.250 g/liter sodium ampicillin, 0.01 g/liter benomyl, 0.05 g/liter hymexazol, 0.1 g/liter PCNB, 0.05 g/liter pimaricin, and 0.01 g/liter rifamycin) and incubated at 20{\textdegree}C in darkness. Growing hyphae were later transferred to PDA media and incubated at 20{\textdegree}C in the dark. The colony pattern was stellate. The average radial growth rate at 20 {\textdegree}C was 0.6 cm/day. These morphological features are similar to that previously described for P. gonapodyides (Corcobado et al., 2010; Erwin \& Ribeiro, 1996; Jung et al., 1996). The isolates grown on PDA formed irregularly branched hyphae. Nonpapillate, elongated-ovoid to obpyriform sporangia (approximately 50 x 40 {\textmu}m) were produced after 7 days by incubating on V8 agar culture (non-sterile soil water). DNA was extracted from mycelia and the identity of P. gonapodyides was confirmed by sequencing the internal transcribed (ITS) spacer region of the rDNA with the primers ITS4/ITS6 [GenBank Accession Nos. KX055998, KX055999, KX056000]. Blast search showed 99-100\% identity with reference sequences of P. gonapodyides deposited in GenBank (NCBI). Pathogenicity on F. sylvatica was confirmed in a greenhouse experiment using two different isolates of P. gonapodyides. Mycelial plugs of 3-week-old cultures of each isolate grown on PDA were inoculated on the stems of 1-year-old seedlings at two locations, separated by 20 cm, by aseptically excising a small 5-mm flap of bark, inserting the mycelial plug along the cambium and adding a droplet of Milliq H2O before sealing the wound with Parafilm{\textregistered}. Ten seedlings were inoculated for each isolate. Controls consisted of stem-wound inoculation with a sterile plug of PDA, and no wounding at all. After 7 weeks, lesion length was measured. All seedlings inoculated with P. gonapodyides showed distinct necrotic lesions, whereas control treatments did not show any symptoms of disease. The average cumulative lesion length on seedlings inoculated with P. gonapodyides was significantly higher than on the wounded control treatment (25.4 mm, {\textpm}1.66 vs. 0.4 mm, {\textpm}0.01; P\<0.0001 for Isolate 1 and 28.9 mm, {\textpm}1.42 vs. 0.4 mm, {\textpm}0.01; P\<0.001 for Isolate 2). Koch{\textquoteright}s postulates were fulfilled by successfully reisolating the pathogen from infected seedlings. To our knowledge, this is the first report of P. gonapodyides causing disease on trees in Sweden. P. gonapodyides has been noted previously in Denmark (Erwin and Ribeiro, 1996), and has been traditionally regarded as a weak parasite with saprophytic abilities, usually associated with aquatic environments such as rivers, riparian areas and wetlands (Brasier et al., 2003). We cannot exclude that recent climatic triggers such as high summer precipitation coupled with mild winter temperatures have favored conditions to multicyclic spread of P. gonapodyides via zoospores, or that increased average age of beech stands has contributed to their higher susceptibility to weaker pathogens. Damage caused by P. gonapodyides however might be underestimated as it also can inhibit seed germination, and is known to cause root rot and stem lesions in Q. robur and Q. ilex (Jung et al. 1996; Corcobado et al. 2010). The newly reported damage caused by P. gonapodyides on F. sylvatica trees in Southern Sweden is alarming particularly since beech is a dominant and ecologically important hardwood species that is widely used in forestry and as a planted ornamental in urban and landscape settings. Furthermore, other hosts such as Alnus glutinosa, Quercus petraea, Q. robur (Jung et al., 1996), Picea abies, Betula spp., Acer spp., Tilia spp., (Jung et al., 2009) and Salix spp. (Brasier et al., 2003), also common in southern Sweden, may face an increased risk of damages caused by P. gonapodyides in the future.

}, issn = {0191-2917}, doi = {10.1094/PDIS-04-16-0468-PDN}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-04-16-0468-PDN}, author = {Cleary, Michelle and Ghasemkhani, Marjan and Blomquist, Mimmi and Witzell, Johanna} } @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 {EFP:EFP718, title = {The long-term survival of Phytophthora cinnamomi in mature Banksia grandis killed by the pathogen}, journal = {Forest Pathology}, volume = {42}, year = {2012}, month = {02/2012}, pages = {28{\textendash}36}, publisher = {Blackwell Publishing Ltd}, abstract = {

The ability of Phytophthora cinnamomi to survive long dry periods is the key to its persistence in the south-west of Western Australia. It has been proposed that dead Banksia grandis are a significant long-term reservoir for P.\ cinnamomi inoculum. To test this, 36 healthy B.\ grandis trees were inoculated in April 1999, and the presence of viable propagules in planta was determined between 2 and 34\ months after tree death. By 10\ months after inoculation, 75\% of the trees had died, with the remaining seven trees dying by 22\ months. The pathogen was more commonly recovered from bark than from wood, except from those trees that died at 22\ months, and more commonly from above-ground trunks than below-ground trunks and roots until 8\ months after plant death. In trees that died 12\ months after inoculation, P.\ cinnamomi was recovered from 60\% of trunk and root core samples at 3\ months, declining to 33\% at 10\ months, 5.5\% at 12\ months and 0.1\% at 34\ months after tree death. In trees that died at 22\ months, P.\ cinnamomi was recovered from 87\% of trunk and root samples 2\ months after tree death, decreasing to 0.5\% by 33\ months. This study suggests that the pathogen does not have a saprotrophic phase within dead B.\ grandis tissue, and B.\ grandis is unlikely to be a long-term reservoir for P.\ cinnamomi. However, the manipulation of the density of B.\ grandis and the use of fire to facilitate the breakdown of dead Banksia trunks in the Eucalyptus marginata (jarrah) forest may reduce the spread and impact of P.\ cinnamomi.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00718.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00718.x}, author = {Collins, S. and McComb, J. A. and Howard, K. and Shearer, B. L. and Colquhoun, I. J. and Hardy, G. E. St. J.} } @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 {3969, title = {Genetic diversity of European populations of the oak fine-root pathogen Phytophthora quercina}, journal = {Forest Pathology}, volume = {35}, year = {2005}, month = {02/2005}, pages = {57 - 70}, abstract = {

The recently discovered oak-specific fine root plant pathogen Phytophthora quercina is a significant factor in the current phase of European oak decline but its origins and ecology are poorly understood. A genome-wide analysis of 260 amplified fragment length polymorphism (AFLP) markers was used to examine the genetic diversity of 72 isolates from five oak species at 28 sites in Germany (particularly Bavaria), Italy, France, Hungary and the UK. Within-site diversity was examined at 16 sites. The limited genetic diversity (within and between sites) and lack of genetic substructuring according to geographic origin or host species suggest the rapid spread of a relatively recently introduced species. Two subgroups were distinguished and these may reflect an initial introduction of isolates of two different genetic backgrounds. The relatively low genetic diversity is probably because of the predominantly inbreeding (homothallic) nature of P. quercina. However, evidence of limited intra-site diversity, temporal variation and the lack of clonality within the European population suggest that some diversity is being maintained by occasional outcrossing and turnover of a reservoir of long-lived soil-borne oospore (sexually derived) inoculum.

}, issn = {1437-4781}, doi = {10.1111/efp.2005.35.issue-110.1111/j.1439-0329.2004.00384.x}, author = {Cooke, D. E. L. and T. Jung and Williams, N. A. and Schubert, R. and W. O{\ss}wald and Duncan, J. M.} } @article {Cooke200017, title = {A molecular phylogeny of Phytophthora and related Oomycetes}, journal = {Fungal Genetics and Biology}, volume = {30}, number = {1}, year = {2000}, pages = {17-32}, abstract = {

Phylogenetic relationships among 50 Phytophthora species and between Phytophthora and other oomycetes were examined on the basis of the ITS sequences of genomic rDNA. Phytophthora grouped with Pythium, Peronospora, and Halophytophthora, distant from genera in the Saprolegniales. Albugo was intermediate between these two groups. Unlike Pythium, Phytophthora was essentially monophyletic, all but three species forming a cluster of eight clades. Two clades contained only species with nonpapillate sporangia. The other six clades included either papillate and semipapillate, or semipapillate and nonpapillate types, transcending traditional morphological groupings, which are evidently not natural assemblages. Peronospora was related to P. megakarya and P. palmivora and appears to be derived from a Phytophthora that has both lost the ability to produce zoospores and become an obligate biotroph. Three other Phytophthoras located some distance from the main Phytophthora-Peronospora cluster probably represent one or more additional genera.

}, keywords = {evolution, internal transcribed spacers, ITS, Peronospora., Pythium, rDNA}, issn = {1087-1845}, doi = {DOI: 10.1006/fgbi.2000.1202}, url = {http://www.sciencedirect.com/science/article/B6WFV-45FC03G-1G/2/1cb8ec25d08dae3a16f56e74cd92e99e}, author = {Cooke, D. E. L. and A. Drenth and Duncan, J. M. and G. Wagels and C.M. Brasier} } @article {3962, title = {First report of Phytophthora gonapodyides involved in the decline of Quercus ilex in xeric conditions in Spain}, journal = {New Disease Reports}, volume = {22}, year = {2010}, month = {12/2010}, pages = {33}, abstract = {

Over the last three decades an intense dieback of holm oak (Quercus ilex) has been recorded in southwest Spain, with Phytophthora cinnamomi and water stress believed to be the major factors involved (Romero et al., 2007; Solla et al., 2009). In 2009, P. cinnamomi and Pythium spiculum were recovered during all seasons from soil and roots from trees showing characteristic symptoms in five declining Q. ilex stands in the province of C{\'a}ceres, Extremadura, SW Spain. In October 2009, a different Phytophthora species was isolated from roots and from rhizosphere soil of a single tree located in Malpartida de Plasencia (39{\textdegree}58{\textquoteright}N 6{\textdegree}5{\textquoteright}W, 443 m above sea level), using young Q. robur and Q. ilex leaves as baits and V8-PARPH agar as a selective medium (Jung et al., 1996). The heterothallic isolates formed irregularly branched hyphae, but no chlamydospores or hyphal swellings were observed. Nonpapillate elongated-ovoid to obpyriform sporangia (28-58 x 25-40 {\textmu}m) with exit pores of 10-20 {\textmu}m were produced by flooding one cm squares from the growing margin of a V8-agar culture for 24 h in non-sterile soil-extract. The colony pattern on V8 agar was stellate, and the average radial growth rates at 20, 25 and 30{\textdegree}C were 2.5-2.7, 2.5-2.7 and 2.2-2.3 mm/day, respectively. All these features are typical of P. gonapodyides (Erwin \& Ribeiro, 1996; Jung et al., 1996). The identity was confirmed by sequencing the internal transcribed spacer region of the rDNA with the primers ITS4/ITS6 (GenBank Accession No. GU724194).

Because P. gonapodyides causes root rot and stem lesions in Q. robur (Jung et al., 1996; Balci \& Halmschlager, 2003), pathogenicity tests on one-year-old Q. ilex seedlings were performed. Thirty plants were grown on 250 ml pots containing a mixture of sand and peat (1:1). For inoculum preparation (Romero et al., 2007), the isolate was grown in petri dishes containing 20 ml of carrot broth at 20{\textdegree}C in darkness. After four weeks of incubation, the liquid medium was discarded, and the mycelium was washed, added to sterile water, shaken and mixed for three minutes. Each pot was inoculated with the mycelium harvested from one petri dish. Plants were kept at an average temperature of 25{\textdegree}C in natural daylight. Three months after inoculation, mortality of infected plants was 53\%, and mean survival time ({\textpm}SD) of infected plants was 71{\textpm}15 days. For comparison, additional plants were inoculated in the same way with P. cinnamomi. After three months, mortality of Q. ilex seedlings was 94\% and mean survival time 28{\textpm}7 days. The pathogens were consistently re-isolated from the roots of the dead plants. Control plants did not show any symptoms of disease. To our knowledge, this is the first report of P. gonapodyides in Spain. This pathogen has always been associated with moist sites (Hansen \& Delatour, 1999; Balci \& Halmschlager, 2003), in contrast to our findings, in which mean volumetric soil moisture values at 30 and at 100 cm depth (loam soil) were 11.4 and 22.1\% respectively, and the mean soil water table depth was 4.6 m. Under field conditions, further research about the involvement of this pathogen in Q. ilex decline will be undertaken

}, keywords = {Phytophthora cinnamomi, soil moisture, soil water table}, doi = {10.5197/j.2044-0588.2010.02210.5197/j.2044-0588.2010.022.033}, author = {Corcobado, T. and Cubera, E. and P{\'e}rez-Sierra, A. and T. Jung and Solla, A.} } @article {grandall1950distribution, title = {The distribution and significance of the chestnut root rot Phytophthoras, P. cinnamomi and P. cambivora.}, journal = {Plant Disease Reporter}, volume = {34}, number = {6}, year = {1950}, pages = {194{\textendash}6}, abstract = {

A review of literature, with special reference to some recent publications in Spain and Portugal [cf. For. Abstr. 11 (Nos. 1468, 2268)]. The author concludes that Phytophthora cinnamomi plays a great part in disease of Chestnut in Spain, Portugal, France and Italy, and elsewhere in southern Europe, and is probably the major cause of death in the more southerly regions. P. cinnamomi has a considerable range of hosts. It has been found to attack Castanea sativa, Juglans regia, Pseudotsuga taxifolia, Quercus robur, Q. suber, Betula alba, Cedrus atlantica, Abies nordmanniana, A. alba, A. sibirica and Castanea crenata var. tamba. A close watch on Douglas Fir in the U.S.A. seems advisable in case a strain of the fungus should encounter and attack it. In contrast P. cambivora has only been found on Castanea sativa and C. crenata var. tamba.

}, keywords = {Abies alba disease, Abies nordmanniana, Abies sibirica, Betula alba, Castanea crenata, Castanea sativa diseases, Cedrus atlantica, decay, Disease, fungal diseases, Ink disease, Juglans regia disease, Pseudotsuga laxifolia diseases, Quercus robur, Quercus suber disease, trees}, url = {http://www.cabdirect.org/abstracts/19500602345.html}, author = {Crandall, B.S.} } @article {263, title = {Root disease of Castanea species and some coniferous and broadleaf nursery stocks, caused by Phytophthora cinnamomi}, journal = {Phytopathology}, volume = {35}, year = {1945}, pages = {162-180.}, abstract = {

The fungus, Phytophthora cinnamomi Rands, is responsible for a destructive root rot of Chestnut and Chinkapin trees (Castanea spp.) in the United States. The author gives an outline of the work leading to the identification of the fungus, and reports on inoculation and field tests that have proved its pathogenicity on Chestnut and other hosts. The fungus causes a similar root disease in forest-tree nursery stock. Infection has been observed in the nursery on twenty broadleaf and coniferous species. Field and greenhouse inoculation tests have demonstrated the susceptibility to the disease of European Chestnut (Castanea sativa). The Asiatic species, C. crenata, C. mollissima, C. henryi, and C. seguinii, however, show a high degree of resistance. It seems probable that root rot of this type has been responsible for the recession of the American Chestnut in some areas of the United States. No satisfactory control measures have been evolved. Hybrid varieties resistant to both blight and root rot are being developed by crossing American Chestnut and Chinkapins with Asiatic species.

}, issn = {0031-949X}, author = {Crandall, B.S. and G.F. Gravatt and M.M. Ryan} } @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 {4001, title = {Assessment of Australian native annual/herbaceous perennial plant species as asymptomatic or symptomatic hosts of Phytophthora cinnamomi under controlled conditions}, journal = {Forest Pathology}, volume = {43}, year = {2013}, month = {06/2013}, pages = {245{\textendash}251}, abstract = {

Phytophthora cinnamomi is a necrotrophic pathogen of woody perennials and devastates many biomes worldwide. A controlled perlite{\textendash}hydroponic system with no other hyphae-producing organisms as contaminants present allowed rapid assessment of ten annual and herbaceous perennial plant species most of which have a wide distribution within the jarrah (Eucalyptus marginata) forest in Western Australia where this pathogen has been introduced. As some annuals and herbaceous perennials have recently been reported as symptomatic and asymptomatic hosts, laboratory screening of some of the field-tested annuals and herbaceous perennials and additional species was used to further evaluate their role in the pathogen{\textquoteright}s disease cycle. Nine of the species challenged with the pathogen were asymptomatic, with none developing root lesions; however, Trachymene pilosa died. The pathogen produced thick-walled chlamydospores and stromata in the asymptomatic roots. Furthermore, haustoria were observed in the roots, indicating that the pathogen was growing as a biotroph in these hosts.

}, doi = {10.1111/efp.12027}, url = {http://onlinelibrary.wiley.com/doi/10.1111/efp.12027/abstract}, author = {Crone, M. and McComb, J. A. and O{\textquoteright}Brien, P. A. and Hardy, G. E. St J.}, editor = {Andrea, V.} } @article {PPA:PPA12016, title = {Annual and herbaceous perennial native Australian plant species are symptomless hosts of Phytophthora cinnamomi in the Eucalyptus marginata (jarrah) forest of Western Australia}, journal = {Plant Pathology}, volume = {43}, year = {2012}, month = {11/2012}, pages = {245{\textendash}251}, abstract = {

Resistant annual and herbaceous perennial plant species were identified as key hosts which allow Phytophthora cinnamomi to persist on severely impacted black gravel sites within the Eucalyptus marginata (jarrah) forest of southwest Western Australia. Of the annual and herbaceous perennial plant species present on black gravel sites, 15 out of 19 species were found to be hosts of P.\ cinnamomi, and 10 of these were symptomless hosts. In particular, the native annual Trachymene pilosa and the two native herbaceous perennials Stylidium diuroides and Chamaescilla corymbosa were commonly found to be hosts of the pathogen. Species from 12 new genera including three from new families (Crassulaceae, Droseraceae and Primulaceae) are reported for the first time to be hosts of P.\ cinnamomi. The species from which P.\ cinnamomi was recovered were the native species: Chamaescilla corymbosa, Crassula closiana, Drosera erythrorhiza, Hydrocotyle callicarpa, Levenhookia pusilla, Paracaleana nigrita, Podotheca angustifolia, Pterochaeta paniculata, Rytidosperma caespitosum, Siloxerus multiflorus, Stylidium diuroides and Trachymene pilosa, and the introduced annual weeds Hypochaeris glabra, Lysimachia arvensis and Pentameris airoides.

}, keywords = {dieback, host species, jarrah forest, pathogen survival, Phytophthora cinnamomi, susceptibility rating}, issn = {1365-3059}, doi = {10.1111/ppa.12016}, url = {http://dx.doi.org/10.1111/ppa.12016}, author = {Crone, M. and McComb, J. A. and O{\textquoteright}Brien, P. A. and Hardy, G. E. St J.} } @article {4214, title = {Host removal as a potential control method for Phytophthora cinnamomi on severely impacted black gravel sites in the jarrah forest}, journal = {Forest Pathology}, volume = {44}, year = {2014}, month = {Jan-04-2014}, pages = {154 - 159}, abstract = {

Removal of living plants from an area of Eucalyptus marginata (jarrah) forest on black gravel sites infested with Phytophthora cinnamomi significantly reduced subsequent pathogen recovery. Vegetation, including trees and annual and herbaceous perennial plants, was killed on the sites by herbicide application. To determine whether this treatment efficiently eliminated P.\ cinnamomi, soil samples were seasonally collected and baited to test for the presence of the pathogen. There were no recoveries on treated sites in autumn, 28\ months after removal of all vegetation by herbicide application. To test whether this was the result of the complete elimination of the pathogen or whether inoculum remained, regrowth on sites was not controlled after this period leading to the re-establishment of annual and herbaceous perennial species, some of which are hosts of P.\ cinnamomi. Recovery of P.\ cinnamomi after plant regrowth on the formerly treated sites indicated that for complete pathogen removal, sites need to remain free of vegetation for longer than 28\ months. Overall, however, this study confirms that the pathogen is a weak saprophyte, and withdrawal of host material for a period of time may make eventual rehabilitation of these sites possible.

}, doi = {10.1111/efp.2014.44.issue-210.1111/efp.12080}, url = {http://doi.wiley.com/10.1111/efp.2014.44.issue-2http://doi.wiley.com/10.1111/efp.12080}, author = {Crone, M. and McComb, J. A. and O{\textquoteright}Brien, P. A. and Hardy, G. E. St J.}, editor = {Andrea, V.} } @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 {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.} }