00527nas a2200157 4500008004100000245008600041210006900127300001200196490000700208100001700215700001900232700001800251700001400269700001700283856006900300 2000 eng d00aPhytophthora cinnamomi as a cause of oak mortality in the state of Colima, Mexico0 aPhytophthora cinnamomi as a cause of oak mortality in the state  a394-3980 v841 aTainter, F H1 aO’Brien, J G1 aHernández, A1 aOrozco, F1 aRebolledo, O uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2000.84.4.39403265nas a2200169 4500008004100000245013800041210006900179300001200248490000700260520269100267100001402958700001502972700001302987700001603000700001703016856006203033 2006 eng d00aFirst report of root rot and stem canker caused by Phytophthora cambivora on noble fir (Abies procera) for bough production in Norway0 aFirst report of root rot and stem canker caused by Phytophthora  a682-6820 v903 a

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’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).

1 aTalgø, V1 aHerrero, M1 aToppe, B1 aKlemsdal, S1 aStensvand, A uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PD-90-0682B02252nas a2200277 4500008004100000022001400041245016800055210006900223260002900292300001400321490000800335520129600343653001601639653003301655653001001688653002701698653001801725100003201743700002201775700002301797700003701820700001901857700001701876700002601893856005501919 2012 eng d a1439-043400aGrowth enhancement, amino acid synthesis and reduction in susceptibility towards Phytophthora megakarya by arbuscular mycorrhizal fungi inoculation in cocoa plants0 aGrowth enhancement amino acid synthesis and reduction in suscept bBlackwell Publishing Ltd a220–2280 v1603 a

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 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.

10aamino acids10aarbuscular mycorrhizal fungi10acocoa10aPhytophthora megakarya10aplant disease1 aTchameni, Séverin Nguemezi1 aNwaga, Dieudonné1 aWakam, Louise Nana1 aMangaptche Ngonkeu, Eddy Leonard1 aFokom, Raymond1 aKuaté, Jean1 aEtoa, Francois-Xavier uhttp://dx.doi.org/10.1111/j.1439-0434.2012.01888.x01782nas a2200193 4500008004100000245005200041210005200093260001600145300001400161490000700175520113100182100001901313700002101332700001901353700001701372700001101389700002701400856016101427 2015 eng d00aPhytophthora cambivora found on beech in Norway0 aPhytophthora cambivora found on beech in Norway cJan-10-2015 a415 - 4250 v453 a

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 Ås. 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 Ås, 9.2% of the trees had bleeding cankers. Isolation from diseased beech in both Larvik and Ås 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.

1 aTelfer, K., H.1 aBrurberg, M., B.1 aHerrero, M.-L.1 aStensvand, A1 aø, V.1 aDesprez-Loustau, M.-L. uhttp://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.1221502000nas a2200169 4500008004100000022001400041245012600055210006900181300000600250520139100256653001801647100002601665700002101691700002601712700002101738856007101759 2012 eng d a1754-504800aInhibition of Phytophthora species by secondary metabolites produced by the dark septate endophyte Phialocephala europaea0 aInhibition of Phytophthora species by secondary metabolites prod a-3 a

Dark septate fungal root endophytes of the Phialocephala fortinii s.l.–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.

10aSclerotinin A1 aTellenbach, Christoph1 aSumarah, Mark, W1 aGrünig, Christoph, R1 aMiller, David, J uhttp://www.sciencedirect.com/science/article/pii/S175450481200128602058nas a2200205 4500008004100000245012900041210006900170260001200239300001400251490000700265520139800272100001401670700001801684700001501702700001901717700001801736700001801754700001401772856006601786 2013 eng d00aA TaqMan real-time PCR assay for the detection of Phytophthora ‘taxon Agathis’ in soil, pathogen of Kauri in New Zealand0 aTaqMan realtime PCR assay for the detection of Phytophthora taxo c04/2013 a324–3300 v433 a

Kauri Agathis australis, an iconic tree of New Zealand, is under threat from an introduced disease-causing pathogen provisionally named Phytophthora ‘taxon Agathis’ (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.

1 aThan, D J1 aHughes, K J D1 aBoonhan, N1 aTomlinson, J A1 aWoodhall, J W1 aBellgard, S E1 aAndrea, V uhttp://onlinelibrary.wiley.com/doi/10.1111/efp.12034/abstract00458nas a2200133 4500008004100000245008600041210006900127300001100196490000700207100001600214700001400230700001600244856006400260 2007 eng d00aRisk factors for the Phytophthora-induced decline of alder in northeastern France0 aRisk factors for the Phytophthorainduced decline of alder in nor a99-1050 v971 aThoirain, B1 aHusson, C1 aMarçais, B uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-97-009901105nas a2200133 4500008004100000245008800041210007100129260001600200520058900216100001600805700002300821700001400844856011300858 2016 eng d00aPhytophthora species isolated from ash stands in Białowieża Forest nature reserve0 aPhytophthora species isolated from ash stands in Białowieża Fore cJan-06-20163 a

Five Phytophthora species were isolated from the rhizosphere of ash-dominated areas of the Białowieza 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.

1 aTkaczyk, M.1 aNowakowska, J., A.1 aOszako, T uhttp://doi.wiley.com/10.1111/efp.12295http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fefp.1229501988nas a2200193 4500008004100000022001400041245010400055210006900159260001600228300001600244490000700260520139300267100001901660700001601679700001801695700002001713700001501733856004601748 2005 eng d a0099-224000aOn-Site DNA Extraction and Real-Time PCR for Detection of Phytophthora ramorum in the FieldABSTRACT0 aOnSite DNA Extraction and RealTime PCR for Detection of Phytopht cJan-11-2005 a6702 - 67100 v713 a

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.

1 aTomlinson, J A1 aBoonham, N.1 aHughes, K J D1 aGriffin, R., L.1 aBarker, I. uhttps://pubmed.ncbi.nlm.nih.gov/16269700/01645nas a2200157 4500008004100000245012200041210006900163260001600232300001400248490000800262520111000270100002001380700002101400700002301421856004301444 2014 eng d00aEffects of Inoculum Density and Wounding on Stem Infection of Three Eastern US Forest Species by Phytophthora ramorum0 aEffects of Inoculum Density and Wounding on Stem Infection of Th cJan-03-2014 a683 - 6890 v1623 a

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 (2–3 years old) did not differ significantly from older seedlings (5–6 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.

1 aTooley, Paul, W1 aBrowning, Marsha1 aLeighty, Robert, M uhttp://doi.wiley.com/10.1111/jph.1225101536nas a2200169 4500008004100000022001400041245009300055210006900148260002900217300001200246520097500258653001801233653001901251100002001270700002101290856005501311 2011 eng d a1439-043400aEnhanced recovery of Phytophthora ramorum from soil following 30 Days of storage at 4°C0 aEnhanced recovery of Phytophthora ramorum from soil following 30 bBlackwell Publishing Ltd ano–no3 a

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°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°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°C may allow for pathogen activity, such as sporangia production, which may enhance recovery from soil.

10achlamydospore10aramorum blight1 aTooley, Paul, W1 aCarras, Marie, M uhttp://dx.doi.org/10.1111/j.1439-0434.2011.01810.x02402nas a2200145 4500008004100000245011000041210006900151260001300220300001400233490000800247520192100255100002002176700002102196856003902217 2016 eng d00aThe Effect of Exposure to Decreasing Relative Humidity on the Viability of Phytophthora ramorum sporangia0 aEffect of Exposure to Decreasing Relative Humidity on the Viabil cAug 2016 a874 - 8810 v1643 a

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°C in darkness. Plastic containers (21.5 × 14.5 × 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 × 1.5 cm, 15 micron pore size) which were placed in the humidity chambers and incubated at 20°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 Pramorum sporangia germination can shed light on pathogenesis and epidemic potential and lead to improved control recommendations.

1 aTooley, Paul, W1 aBrowning, Marsha uhttps://doi.org/10.1111/jph.12506 01997nas a2200157 4500008004100000245010700041210006900148260001200217300001400229490000800243520145800251100002001709700002101729700002301750856006601773 2013 eng d00aInoculum density relationships for infection of some eastern US forest species by Phytophthora ramorum0 aInoculum density relationships for infection of some eastern US  c09/2013 a595–6030 v1613 a
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 ‘Cunningham's White’ were dip-inoculated with varying numbers of P. ramorum sporangia, and the total number of diseased and healthy leaves recorded following incubation at 20°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.
1 aTooley, Paul, W1 aBrowning, Marsha1 aLeighty, Robert, M uhttp://onlinelibrary.wiley.com/doi/10.1111/jph.12107/abstract00600nas a2200169 4500008004100000022002300041245007500064210006900139260007300208300001000281653002300291653002100314100001800335700001800353700002200371856003700393 1954 eng d aStationBulletin53700aPhytophthora root rot diseases of Lawson cypress and other ornamentals0 aPhytophthora root rot diseases of Lawson cypress and other ornam aCorvallis, ORbOregon State College. Agricultural Experiment Station a18 p.10aDiseases and pests10aOrnamental trees1 aTorgeson, D C1 aYoung, Roy, A1 aMilbrath, John, A uhttp://hdl.handle.net/1957/1534900538nas a2200121 4500008004100000245010100041210006900142260004000211300000700251490000800258100001700266856013300283 1953 eng d00aEpiphytology and etiology of a Phytophthora-induced root rot diseases of Chamaecyparis in Oregon0 aEpiphytology and etiology of a Phytophthorainduced root rot dise aCorvallis, ORbOregon State College a720 vPhD1 aTorgeson, DC uhttps://forestphytophthoras.org/references/epiphytology-and-etiology-phytophthora-induced-root-rot-diseases-chamaecyparis-oregon00416nas a2200109 4500008004100000245005800041210005800099300001400157490000700171100002200178856010600200 1974 eng d00aSporulation and germination of Phytophthora lateralis0 aSporulation and germination of Phytophthora lateralis a1531-15330 v641 aTrione, Edward, J uhttp://www.apsnet.org/publications/phytopathology/backissues/Documents/1974Abstracts/Phyto64_1531.htm00448nas a2200109 4500008004100000245007900041210006900120300001400189490000700203100001600210856011200226 1959 eng d00aThe pathology of Phytophthora lateralis on native Chamaecyparis lawsoniana0 apathology of Phytophthora lateralis on native Chamaecyparis laws a306–3100 v491 aTrione, E J uhttps://forestphytophthoras.org/references/pathology-phytophthora-lateralis-native-chamaecyparis-lawsoniana01921nas a2200133 4500008004100000245005500041210005400096300000800150490000700158520149500165100001501660700001801675856009401693 2010 eng d00aDetection and identification of Phytophthora alni.0 aDetection and identification of Phytophthora alni a6550 v753 a

In 2004 Brasier et al. described new species–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’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.

1 aTrzewik, A1 aOrlikowska, T uhttps://forestphytophthoras.org/references/detection-and-identification-phytophthora-alni00426nas a2200133 4500008004100000245006600041210006600107300001100173490000700184653002700191100001600218700001800234856004000252 1942 eng d00aRoot rot of Chamaecyparis caused by a species of Phytophthora0 aRoot rot of Chamaecyparis caused by a species of Phytophthora a94-1030 v3410aPhytophthora lateralis1 aTucker, C M1 aMilbrath, J A uhttp://www.jstor.org/stable/375494504657nas a2200181 4500008004100000022001400041245011600055210006900171260001600240300001600256490000800272520405500280100002104335700001604356700001704372700002004389856006604409 2016 eng d a0191-291700aFirst Report of Phytophthora chlamydospora Causing Root and Crown Rot on Almond (Prunus dulcis) Trees in Turkey0 aFirst Report of Phytophthora chlamydospora Causing Root and Crow cJan-08-2016 a1796 - 17960 v1003 a

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 Adıyaman 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°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°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°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’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.

1 aTürkölmez, Ş.1 aDerviş, S.1 aÇiftçi, O.1 aSerçe, Ç., U. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-02-16-0155-PDN02934nas a2200745 4500008004100000245009400041210006900135300001400204490000800218520077400226100002001000700002201020700001801042700002001060700002101080700001801101700002501119700001801144700002101162700001901183700002001202700002801222700002201250700001701272700002401289700002101313700002301334700001701357700002201374700002101396700002501417700001701442700002001459700002201479700002001501700002601521700002001547700001801567700002301585700002301608700002401631700002201655700002301677700003001700700002001730700002501750700002401775700001401799700002301813700002101836700002101857700001801878700002601896700002001922700002301942700001801965700002801983700001302011700001602024700001902040700002302059700002302082700002202105856006102127 2006 eng d00aPhytophthora genome sequences uncover evolutionary origins and mechanisms of pathogenesis0 aPhytophthora genome sequences uncover evolutionary origins and m a1261-12660 v3133 a

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’ 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.

1 aTyler, Brett, M1 aTripathy, Sucheta1 aZhang, Xuemin1 aDehal, Paramvir1 aJiang, Rays, H Y1 aAerts, Andrea1 aArredondo, Felipe, D1 aBaxter, Laura1 aBensasson, Douda1 aBeynon, Jim, L1 aChapman, Jarrod1 aDamasceno, Cynthia, M B1 aDorrance, Anne, E1 aDou, Daolong1 aDickerman, Allan, W1 aDubchak, Inna, L1 aGarbelotto, Matteo1 aGijzen, Mark1 aGordon, Stuart, G1 aGovers, Francine1 aGrunwald, Niklaus, J1 aHuang, Wayne1 aIvors, Kelly, L1 aJones, Richard, W1 aKamoun, Sophien1 aKrampis, Konstantinos1 aLamour, Kurt, H1 aLee, Mi-Kyung1 aMcDonald, Hayes, W1 aMedina, M√>=nica1 aMeijer, Harold, J G1 aNordberg, Eric, K1 aMaclean, Donald, J1 aOspina-Giraldo, Manuel, D1 aMorris, Paul, F1 aPhuntumart, Vipaporn1 aPutnam, Nicholas, H1 aRash, Sam1 aRose, Jocelyn, K C1 aSakihama, Yasuko1 aSalamov, Asaf, A1 aSavidor, Alon1 aScheuring, Chantel, F1 aSmith, Brian, M1 aSobral, Bruno, W S1 aTerry, Astrid1 aTorto-Alalibo, Trudy, A1 aWin, Joe1 aXu, Zhanyou1 aZhang, Hongbin1 aGrigoriev, Igor, V1 aRokhsar, Daniel, S1 aBoore, Jeffrey, L uhttp://www.sciencemag.org/content/313/5791/1261.abstract