@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 {doi:10.1094/PD-90-0682B, title = {First report of root rot and stem canker caused by Phytophthora cambivora on noble fir (Abies procera) for bough production in Norway}, journal = {Plant Disease}, volume = {90}, number = {5}, year = {2006}, pages = {682-682}, abstract = {

In 2004, damages resembling those caused by Phytophthora spp. were observed in a 15-year-old bough plantation of noble fir (Abies procera). When removing bark upward from the roots and base of a diseased tree, a reddish brown discoloration with distinct borders to surrounding wood appeared. The discoloration extended approximately 1.5 m above ground, but only on one side of the stem. This resulted in dead basal branches (flagging) on the cankered side of the tree. Other dying trees in the same field did not show flagging symptoms but turned chlorotic to brown after being girdled by the expanding stem canker. Approximately 25\% of the trees were dead or dying. Isolations were carried out from the area between healthy and diseased tissue both from roots and base of the stem of the tree with flagging symptoms. Samples were rinsed in running tap water and plated on the Phytophthora selective medium PARP (17 g of cornmeal agar, 10 mg of pimaricin, 250 mg of ampicillin, 10 mg of rifampicin, and 100 mg of pentachloronitrobenzene (PCNB) in 1 liter of water), with and without hymexazol added (50 mg/l). Morphological characters of the isolated Phytophthora sp. included nonpapillate sporangia (37 to 64 μm), internal proliferation, and characteristic hyphal swellings. The isolate was heterothallic and produced amphigynous antheridia when crossed with tester strains of P. cryptogea. The mating type was A2. The internal transcribed spacer (ITS) rDNA sequences were identical to P. cambivora (GenBank Accession No. AY880985). Thus, both morphological characters and DNA analysis supported the species identification. A pathogenesis test to fulfill Koch{\textquoteright}s postulate was carried out during 2005. Inoculation was done by placing agar with culture in the growth medium close to the roots of noble fir seedlings. Eleven weeks after inoculation, clearly visible stem canker symptoms were observed. The ITS sequences of the reisolated Phytophthora sp. were determined and found identical to P. cambivora. P. cambivora was reported to cause root rot and stem canker in a noble fir Christmas tree plantation in the United States (1). P. citricola and P. citrophthora are known to cause problems on Lawson Falsecypress/Port-Orford-cedar (Chamaecyparis lawsoniana) in Norway, but damages by Phytophthora spp. have never been reported in Abies spp. plantations or forest stands in Norway. Currently, we are also working on Phytophthora problems discovered in two different Christmas tree plantations (A. lasiocarpa and A. nordmanniana).

}, doi = {10.1094/PD-90-0682B}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PD-90-0682B}, author = {Talg{\o}, V. and Herrero, M. and Toppe, B. and Klemsdal, S. and Stensvand, A.} } @article {JPH:JPH1888, title = {Growth enhancement, amino acid synthesis and reduction in susceptibility towards Phytophthora megakarya by arbuscular mycorrhizal fungi inoculation in cocoa plants}, journal = {Journal of Phytopathology}, volume = {160}, number = {5}, year = {2012}, pages = {220{\textendash}228}, publisher = {Blackwell Publishing Ltd}, abstract = {

The effects of some selected arbuscular mycorrhizal (AM) fungi, Gigaspora margarita and Glomus mossae on the growth and the role of soluble amino acids of two contrasting cocoa cultivars (ICS84 tolerant and SNK10 sensitive) against black pod disease caused by Phytophthora megakarya were investigated. Root colonization by AM fungi is between 50 and 70\% 18{\textlnot}{\textdagger}weeks after planting. Tested AM fungi significantly increased all the plant growth parameters (height, number of leaves, shoot and root matter) and P uptake as compared to non-inoculated plants in pot experiments. AM fungi inoculated cocoa reduced the disease severity. Compared to the control, the soluble amino acid levels increased with inoculation of the AM fungi strains in the necrotic stems of disease on inoculated cocoa plants. Significant relationships between amino acids and disease severity observed for two cocoa cultivars imply that the induction of specific amino acids synthesized by leaves, such as arginine, cysteine and glutamic acid, may represent potential candidate molecules for adaptation of such cultivars to P. megakarya disease. Inoculating seedlings with AMF in nurseries could enhance the development of cocoa plants protected against P. megakarya.

}, keywords = {amino acids, arbuscular mycorrhizal fungi, cocoa, Phytophthora megakarya, plant disease}, issn = {1439-0434}, doi = {10.1111/j.1439-0434.2012.01888.x}, url = {http://dx.doi.org/10.1111/j.1439-0434.2012.01888.x}, author = {Tchameni, S{\'e}verin Nguemezi and Nwaga, Dieudonn{\'e} and Wakam, Louise Nana and Mangaptche Ngonkeu, Eddy Leonard and Fokom, Raymond and Kuat{\'e}, Jean and Etoa, Francois-Xavier} } @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 {Tellenbach2012, title = {Inhibition of Phytophthora species by secondary metabolites produced by the dark septate endophyte Phialocephala europaea}, journal = {Fungal Ecology}, year = {2012}, pages = {-}, abstract = {

Dark septate fungal root endophytes of the Phialocephala fortinii s.l.{\textendash}Acephala applanata species complex (PAC) are widely distributed throughout the temperate and subtropical regions of the Northern Hemisphere. Previous studies have shown that some PAC members are pathogenic, others suppress oomycete root pathogens and some have no obvious effect on their Norway spruce (Picea abies) host. The activity of 85 PAC isolates against Phytophthora citricola s.l. was investigated by co-culture on plates. We identified a strain of Phialocephala europaea that significantly reduced the growth of P. citricola in\ vitro. Characterization of its extracellular metabolites resulted in the identification of four major compounds, sclerin, sclerolide, sclerotinin A, and sclerotinin B. These compounds are known for their positive as well as negative effects on plant growth. We found that sclerin and sclerotinin inhibited the growth of P. citricola in\ vitro at 150\ μg\ ml-1 (\~{}1\ mM). This is the first report of their production by Phialocephala and of activity of these compounds against an oomycete. Therefore, our data suggest that some PAC might reduce disease resulting from P. citricola by the production of antibiotics and plant growth promoting metabolites.

}, keywords = {Sclerotinin A}, issn = {1754-5048}, doi = {10.1016/j.funeco.2012.10.003}, url = {http://www.sciencedirect.com/science/article/pii/S1754504812001286}, author = {Christoph Tellenbach and Mark W. Sumarah and Christoph R. Gr{\"u}nig and J. David Miller} } @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 {doi:10.1094/PHYTO-97-0099, title = {Risk factors for the Phytophthora-induced decline of alder in northeastern France}, journal = {Phytopathology}, volume = {97}, number = {1}, year = {2007}, pages = {99-105}, doi = {10.1094/PHYTO-97-0099}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-97-0099}, author = {Thoirain, B. and Husson, C. and Mar{\c c}ais, B.} } @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 {4699, title = {On-Site DNA Extraction and Real-Time PCR for Detection of Phytophthora ramorum in the FieldABSTRACT}, journal = {Applied and Environmental Microbiology}, volume = {71}, year = {2005}, month = {Jan-11-2005}, pages = {6702 - 6710}, abstract = {

Phytophthora ramorum is a recently described pathogen causing oak mortality (sudden oak death) in forests in coastal areas of California and southern Oregon and dieback and leaf blight in a range of tree, shrub, and herbaceous species in the United States and Europe. Due to the threat posed by this organism, stringent quarantine regulations are in place, which restrict the movement of a number of hosts. Fast and accurate diagnostic tests are required in order to characterize the distribution of P. ramorum, prevent its introduction into pathogen-free areas, and minimize its spread within affected areas. However, sending samples to a laboratory for testing can cause a substantial delay between sampling and diagnosis. A rapid and simple DNA extraction method was developed for use at the point of sampling and used to extract DNAs from symptomatic foliage and stems in the field. A sensitive and specific single-round real-time PCR (TaqMan) assay for P. ramorum was performed using a portable real-time PCR platform (Cepheid SmartCycler II), and a cost-effective method for stabilizing PCR reagents was developed to allow their storage and transportation at room temperature. To our knowledge, this is the first description of a method for DNA extraction and molecular testing for a plant pathogen carried out entirely in the field, independent of any laboratory facilities.

}, issn = {0099-2240}, doi = {10.1128/AEM.71.11.6702-6710.2005}, url = {https://pubmed.ncbi.nlm.nih.gov/16269700/}, author = {Tomlinson, J. A. and Boonham, N. and Hughes, K. J. D. and Griffin, R. L. and Barker, I.} } @article {4209, title = {Effects of Inoculum Density and Wounding on Stem Infection of Three Eastern US Forest Species by Phytophthora ramorum}, journal = {Journal of Phytopathology}, volume = {162}, year = {2014}, month = {Jan-03-2014}, pages = {683 - 689}, abstract = {

Seedlings of three Eastern US forest species Quercus rubra (northern red oak), Quercus prinus (chestnut oak) and Acer rubrum (red maple) were inoculated by applying Phytophthora ramorum sporangia to stems at different inoculum densities with and without wounding. Disease occurred in all treatments involving wounds, and no disease was observed in unwounded treatments. Younger seedlings (2{\textendash}3\ years old) did not differ significantly from older seedlings (5{\textendash}6\ years old) in disease incidence, but older seedlings sustained smaller lesions compared with younger seedlings. For both old and young seedlings, disease on wounded stems was observed down to the lowest sporangia concentration utilized (500 sporangia/ml for old seedlings and 100 sporangia/ml for young seedlings). The results show that in the presence of wounding, even very low sporangia concentrations can result in disease, and further suggest that wounding caused by insects and other factors may play an important role in P.\ ramorum epidemiology in forest environments.

}, doi = {10.1111/jph.12251}, url = {http://doi.wiley.com/10.1111/jph.12251}, author = {Tooley, Paul W. and Browning, Marsha and Leighty, Robert M.} } @article {JPH:JPH1810, title = {Enhanced recovery of Phytophthora ramorum from soil following 30 Days of storage at 4{\textdegree}C}, journal = {Journal of Phytopathology}, year = {2011}, pages = {no{\textendash}no}, publisher = {Blackwell Publishing Ltd}, abstract = {

Chlamydospores of Phytophthora ramorum were used to infest field soil at densities ranging from 0.2 to 42 chlamydospores/cm3 soil. Recovery was determined by baiting with rhododendron leaf discs and dilution plating at time 0 and after 30\ days of storage at 4{\textdegree}C, as recommended by USDA-APHIS. Baiting was slightly more sensitive than dilution plating in recovering P.\ ramorum immediately following infestation of soil and allowed detection from samples infested with as little as 0.2\ chlamydospores/cm3 compared with 1 chlamydospore/cm3 for dilution plating. After 30\ days of infested soil storage at 4{\textdegree}C, P.\ ramorum was detected at significantly (P\ =\ 0.05) higher levels than at time 0 with both recovery methods. The results indicate that storage of P.\ ramorum-infested soil at 4{\textdegree}C may allow for pathogen activity, such as sporangia production, which may enhance recovery from soil.

}, keywords = {chlamydospore, ramorum blight}, issn = {1439-0434}, doi = {10.1111/j.1439-0434.2011.01810.x}, url = {http://dx.doi.org/10.1111/j.1439-0434.2011.01810.x}, author = {Tooley, Paul W. and Carras, Marie M.} } @article {4556, title = {The Effect of Exposure to Decreasing Relative Humidity on the Viability of Phytophthora ramorum sporangia}, journal = {Journal of Phytopathology}, volume = {164}, year = {2016}, month = {Aug 2016}, pages = {874 - 881}, abstract = {

Sporangia of three isolates of Phytophthora ramorum representing three different clonal lineages were subjected to relative humidity (RH) levels between 80 and 100\% for exposure periods ranging from 1 to 24\ h at 20{\textdegree}C in darkness. Plastic containers (21.5\ {\texttimes}\ 14.5\ {\texttimes}\ 5\ cm) were used as humidity chambers with 130\ ml of glycerine solution added to each container. Glycerine concentrations corresponded to 100, 95, 90, 85 and 80\% RH based on refractive index measurements. Sporangia suspensions were pipeted onto nitrile mesh squares (1.5\ {\texttimes}\ 1.5\ cm, 15 micron pore size) which were placed in the humidity chambers and incubated at 20{\textdegree}C in darkness. Following exposure periods of 1, 2, 4, 8, 12 and 24\ h, mesh squares were inverted onto Petri dishes of selective medium and sporangia germination assessed after 24 and 48\ h. At 100\% RH, we observed a mean value of 88\% germination after 1\ h exposure declining to 18\% germination following 24\ h incubation. At 95\% RH, a steeper decline in germination was noted, with means ranging from 79\% at 1\ h to less than 1\% at 24\ h exposure. At 90\% RH, no germination was noted after 8 or more h exposure, and values were 57\%, 22\% and 3\% germination for the 1, 2 and 4\ h exposures, respectively. Germination was only observed at 1\ h exposure for both the 85\% RH treatment (52\% germination) and the 80\% RH treatment (38\% germination). The three isolates responded similarly\ over the range of RH values tested. The germination response of P.\ ramorum sporangia to RH values between 80\% and 100\% was comparable to that reported for other Phytophthora species. Knowledge of conditions that affect P.\ ramorum sporangia germination can shed light on pathogenesis and epidemic potential and lead to improved control recommendations.

}, doi = {10.1111/jph.2016.164.issue-11pt1210.1111/jph.12506}, url = {https://doi.org/10.1111/jph.12506 }, author = {Tooley, Paul W. and Browning, Marsha} } @article {4009, title = {Inoculum density relationships for infection of some eastern US forest species by Phytophthora ramorum}, journal = {Journal of Phytopathology}, volume = {161}, year = {2013}, month = {09/2013}, pages = {595{\textendash}603}, abstract = {
Our objectives were to establish inoculum density relationships between P.\ ramorum and selected hosts using detached leaf and whole-plant inoculations. Young plants and detached leaves of Quercus prinus (Chestnut oak), Q.\ rubra (Northern red oak), Acer rubrum (red maple), Kalmia latifolia (mountain laurel) and Rhododendron {\textquoteleft}Cunningham{\textquoteright}s White{\textquoteright} were dip-inoculated with varying numbers of P.\ ramorum sporangia, and the total number of diseased and healthy leaves recorded following incubation at 20{\textdegree}C and 100\% relative humidity. Calibration threshold estimates for obtaining 50\% infected leaves based on linear analysis ranged from 36 to 750 sporangia/ml for the five hosts. Half-life (LD50) estimates (the number of spores for which the per cent of diseased leaves reaches 50\% of its total) from asymptotic regression analysis ranged from 94 to 319 sporangia/ml. Statistically significant differences (P\ =\ 0.0076) were observed among hosts in per cent infection in response to increased inoculum density. Inoculum threshold estimates based on studies with detached leaves were comparable to those obtained using whole plants. The results provide estimates of inoculum levels necessary to cause disease on these five P.\ ramorum hosts and will be useful in disease prediction and for development of pest risk assessments.
}, doi = {10.1111/jph.12107}, url = {http://onlinelibrary.wiley.com/doi/10.1111/jph.12107/abstract}, author = {Tooley, Paul W. and Browning, Marsha and Leighty, Robert M.} } @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.} } @mastersthesis {3957, title = {Epiphytology and etiology of a Phytophthora-induced root rot diseases of Chamaecyparis in Oregon}, volume = {PhD}, year = {1953}, pages = {72}, school = {Oregon State College}, address = {Corvallis, OR}, author = {Torgeson,DC} } @article {199, title = {Sporulation and germination of Phytophthora lateralis}, journal = {Phytopathology}, volume = {64}, year = {1974}, pages = {1531-1533}, doi = {10.1094/Phyto-64-1531}, url = {http://www.apsnet.org/publications/phytopathology/backissues/Documents/1974Abstracts/Phyto64_1531.htm}, author = {Edward J. Trione} } @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 {trzewik2010detection, title = {Detection and identification of Phytophthora alni.}, journal = {Communications in agricultural and applied biological sciences}, volume = {75}, number = {4}, year = {2010}, pages = {655}, abstract = {

In 2004 Brasier et al. described new species{\textendash}Phytophthora alni, which was especially aeggressive to alder. Now, this Phytophthora disease of alder is widely distributed in Europe as well as in Poland. In this research note we report on identification and detection of P. alni from water and soil samples using PCR method with species-specific primers. Dilution series of P. alni zoospore were used to test the potential sensitivity of the PCR detection methods. Zoospores of P. alni were produced by flooding of 1-week-old Frozen Pea Medium (FPM) cultures in Petri dishes with 30 ml distilled water. The dishes were incubated at 20 degrees C. After 5 days, sporangial production was checked using a binocular microscope and plates were placed at 4 degrees C for 1 h to enhance zoospore release. Zoospores were counted under the microscope using Burker{\textquoteright}s cabin. A dilution series of zoospores ranging from 5 to 5000 per 200 microl was prepared in autoclaved distilled water and in 1 g samples of autoclaved soil. DNA was extracted from artificially infected water and soil, and purified using the CleanUp Kit (A\&A Biotechnology). Zoospores of P. alni in the water were detected by PCR in 5 x 10(3), 5 x 10(2), 5 x 10(1) concentrations. In case of detecting spores in the artificially infected soil it succeeded only for two highest concentrations, i.e. 5 x 10(3), 5 x 10(2) and only when the DNA was additionally purified.

}, author = {Trzewik, A. and Orlikowska, T.} } @article {195, title = {Root rot of Chamaecyparis caused by a species of Phytophthora}, journal = {Mycologia}, volume = {34}, year = {1942}, pages = {94-103}, keywords = {Phytophthora lateralis}, url = {http://www.jstor.org/stable/3754945}, author = {Tucker, C. M. and Milbrath, J.A.} } @article {4637, title = {First Report of Phytophthora chlamydospora Causing Root and Crown Rot on Almond (Prunus dulcis) Trees in Turkey}, journal = {Plant Disease}, volume = {100}, year = {2016}, month = {Jan-08-2016}, pages = {1796 - 1796}, abstract = {

In June 2015, \~{}10\% of 10,000 8-year-old almond [Prunus dulcis (Miller) D.A. Webb. cv. Ferragnes] trees grafted on the GF677 rootstock in a commercial almond orchard in Besni of Ad{\i}yaman Province, showed wilting and lack of vigor, with severely infected trees dying from root and crown rot. The incidence of infected trees on soils with poor water drainage was greater than that on well-drained soils. Crowns of symptomatic plants had a reddish brown discoloration in the inner bark with a sharp contrast between infected and healthy tissue. Most fine roots were completely rotted and the inner bark of infected larger roots showed similar discoloration. Tissue samples taken from the margins of crown and root lesions were placed on carrot agar (CA) amended with 5 mg of pimaricin, 250 mg of ampicillin, 10 mg of rifampicin, 100 mg of pentachloronitrobenzene, and 50 mg of hymexazol (P5ARPH) per liter. Plates were incubated for 5 days at 28{\textdegree}C in the dark and Phytophthora chlamydospora was consistently isolated from the tissues. Isolates produced petaloid colonies and abundant spherical, thin-walled, intercalary but lateral and terminal chlamydospores (30 to 46 μm diameter, 38.5 μm average). Colonized agar discs were submerged in sterilized deionized water at 25{\textdegree}C. After incubation on submerged discs for 24 h, all isolates produced hyaline, nonpapillate, noncaducous sporangia of ovoid to obpyriform shape, with internal and external proliferation, 34.0 to 56.5 μm long, 26.5 to 39.5 μm wide, with a length/breadth ratio of 1.4 to 1.7, formed on simple, unbranched, occasionally sympodial sporangiophores. Globose to subglobose hyphal swellings in branched chains also formed in water. The optimum and maximum temperatures for mycelium growth on CA were 27 and 37{\textdegree}C, respectively. All these characteristics were similar to those described for P. chlamydospora Brasier and Hansen sp. nov. (Hansen et al. 2015), previously known as P. taxon Pgchlamydo. Genomic DNA was extracted from two representative isolates. The ITS region of rDNA was amplified using the ITS6/ITS4 primer pair and sequenced (GenBank KU647271 and KU647272). BLAST searches showed 99 to 100\% identity to P. chlamydospora isolates, including the type isolate P236 (99\% identity) (AF541900) (Hansen et al. 2015), deposited in GenBank and Phytophthora-ID databases, which confirmed morphological identification. Primary roots of ten 1-year-old P. dulcis cv. Ferragnes seedlings were wounded with a scalpel, and mycelial disks (3 per plant) of P. chlamydospora grown on CA were placed under the cortical tissue, after removing 10 to 15 cm of soil around the root base. The inoculated and exposed roots were then covered with soil. P. chlamydospora caused severe wilt and browning of leaves within 1 and 2 months and extensive root necrosis and rot after 2 months of incubation in a greenhouse. During this period, soil was kept wet by watering plants daily as required. Koch{\textquoteright}s postulates were satisfied after reisolating P. chlamydospora from symptomatic roots of inoculated plants. No disease occurred in 10 controls, similarly inoculated with sterile CA disks, and the pathogen was not recovered from these plants. P. chlamydospora has only rarely been recovered from several ornamental and woody species (Blomquist et al. 2012; Brasier et al. 2003; Ginetti et al. 2014), but not from fruit trees so far. To our knowledge, this is the first report of P. chlamydospora infection of almond, which represents a new host for this pathogen. This is also the first record of P. chlamydospora in Turkey. Within a month, all naturally infected almond trees in this orchard were collapsed and destroyed and the number of infected trees increased dramatically, indicating that it might be a significant threat to almond plantations and orchards, particularly on sites where excess soil water occurs periodically.

}, issn = {0191-2917}, doi = {10.1094/PDIS-02-16-0155-PDN}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-02-16-0155-PDN}, author = {T{\"u}rk{\"o}lmez, {\c S}. and Dervi{\c s}, S. and {\c C}ift{\c c}i, O. and Ser{\c c}e, {\c C}. U.} } @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.} }