04201nas a2200193 4500008004100000022001400041245008600055210006900141260001600210300001600226490000800242520358700250100002103837700002103858700001803879700002103897700002303918856006603941 2016 eng d a0191-291700aFirst Report of Gummosis Caused by Phytophthora frigida on Black Wattle in Brazil0 aFirst Report of Gummosis Caused by Phytophthora frigida on Black cJan-11-2016 a2336 - 23360 v1003 a

Black wattle (Acacia mearnsii), a tree species native to Australia, is considered the main source of bark for the tannin industry worldwide. It is the third most cultivated forest species in Brazil. Gummosis, caused by Phytophthora spp., is a major disease affecting black wattle plantations in that country, where the disease incidence can reach 43%. The most common disease symptoms are lesions on the trunk, which may or may not be accompanied by gum exudation. Severe infection can lead to plant death. Phytophthora nicotianiae and P. bohemeriae were reported as causative agents of black wattle gummosis in Brazil (Santos et al. 2006). In South Africa, besides these species, P. meadii was also recorded on black wattle (Roux and Wingfield 1997), and P. frigida on green wattle (A. decurrens) (Maseko et al. 2007). A survey in 6-year-old black wattle plantations located in the Piratini and Cristal counties in the state of Rio Grande do Sul in 2008 revealed the occurrence of a third Phytophthora species causing gummosis on black wattle in Brazil, P. frigida. Twenty-four isolates were obtained, and all were identified as P. frigida based on morphological characteristics and the sequence of portions of the ITS-5.8S rDNA, and cox I and cox II genes. Morphological characterization of colonies on carrot agar medium (CA) revealed colonies of all isolates with dense aerial mycelium, and five different colony patterns were observed: stellate, cottony, petaloid-to-cottony, slightly stellated, and slightly rosaceous. The colony growth rate was 12 mm/day at 24 to 30°C. All isolates produced sporangia abundantly in 10% nonsterile soil extract when grown under constant light. Most of the sporangia had prominent papilla. Most isolates had persistent sporangia formed singly or in a loose sympodium. The sporangial shape was predominantly ovoid, though there were other shapes such as globose, ellipsoid, and obpyriform found in some isolates, including some distorted shapes. The dimensions of 50 sporangia ranged from 29 to 71 × 20 to 53 µm (avg. 46 × 33 µm), with length-to-breadth ratios of 1.3 to 1.5 (avg. 1.4). The isolates produced globose chlamydospores, terminal or intercalary, and measured 21 to 55 µm diameter (avg. 32 µm). Oogonium diameter ranged from 22 to 37 µm (avg. 30 µm). Antheridia were amphigynous and oospores were globose, aplerotic, and 18 to 31 µm (avg. 24 µm) in diameter. Portions of the ITS-5.8 gene rDNA (730 bp) and the cox I (650 bp) and cox II (650 bp) genes were amplified by PCR. BLAST search of the GenBank database revealed that the fragments for ITS-5.8S gene rDNA (KU570067), and cox I (KU570065), and cox II (KU570066) sequence fragments from isolate P92 were 99 to 100% similar with the accessions of P. frigida (Robideau et al. 2011). To confirm pathogenicity, the 24 isolates of P. frigida was used to inoculate 10 one-year-old black wattle plants. For inoculation, an agar mycelial plug from a 1-week-old colony on CA was put on the stem wound done with a cork borer (6 mm diam.). Necroses of stems were observed 4 weeks after inoculation with the presence, or absence, of gum exudation, as observed initially in the field. P. frigida was reisolated from each infected stem. This is the first report of P. frigida occurring in A. mearnsii worldwide.

1 aAlves, T., C. A.1 aTessmann, D., J.1 aIvors, K., L.1 aRistaino, J., B.1 aSantos, A., F. dos uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-01-16-0134-PDN03368nas a2200145 4500008004100000245011600041210006900157300001400226490000700240520286100247100001703108700001703125700001803142856006203160 2006 eng d00aFirst report of Phytophthora cambivora causing bleeding cankers and dieback on beech (Fagus sylvatica) in Italy0 aFirst report of Phytophthora cambivora causing bleeding cankers  a1362-13620 v903 a

European beech (Fagus sylvatica) is an important forest tree species common in northern and central Europe. In Italy, this species is typical in mountain areas over 1,000 m above sea level. In the last decade, decline and death was reported on European beech caused by several Phytophthora species (2), and P. pseudosyringae was recently reported in Italy (3). During 2004 and 2005, seven declining and dying F. sylvatica trees, older than 20 years, were observed in the Veneto Region of Italy with symptoms of bleeding cankers at the base of trunks and on branches. Cankers on the collar showed tongue-shaped necroses of the inner bark and cambium tissues. Four trees were in a public park of Mestre and three were in a forest stand in the province of Belluno. Samples were taken from declining trees, one in the park and two in the forest. Inner bark and cambium tissue pieces were cut from the canker margins, cultured on CARPBHy-agar (corn meal agar amended with 250 μg ml-1 ampicillin, 10 μg ml-1 rifampicin, 10 μg ml-1 pimaricin, 15 μg ml-1 benomyl, 50 μg ml-1 hymexazol), and incubated at 20°C. Ten morphologically similar isolates were subcultured as single hyphal tips and characterized. These isolates produced nonpapillate sporangia that were ovoid, obpyriform or ellipsoid, and exhibited predominately internal proliferation in soil extract. Hyphal swellings with outgrowths were present under those conditions. The morphological characteristics were consistent with those of P. cambivora (1). Base sequences of the ITS region of rDNA were determined for six of the isolates, and an 832-bp fragment was amplified for each isolate and that sequence was 100% homologous with sequences DQ396418 and AY880985 of P. cambivora in the NCBI database (http://www.ncbi.nlm.nih.gov/BLAST/). The sequence of one isolate, ISPaVe 1950, was deposited in GenBank (Accession No. AM269752). Pathogenicity tests were conducted with 2-year-old potted beech seedlings. Inoculum of representative isolates was grown for 4 weeks on sterilized millet seeds moistened with V8 broth and added to soil at 3% (wt/vol). Control plants received sterilized inoculum only. The soil was flooded for 48 h. Inoculations were performed during May 2005 at 15 to 35°C with six replicates for the inoculated and control plants. The plants were maintained outdoors and assessed after 3 months. Wilt, root rot, and dark brown lesions at the collar developed on inoculated plants, but not on the controls. Symptoms were similar to those on naturally infected trees. The pathogen reisolated from the inoculated plants was morphologically identical to the original isolates, which confirmed P. cambivora as the causal agent. To our knowledge, this is the first report of P. cambivora on beech in Italy.

1 aBelisario, A1 aMaccaroni, M1 aVettorazzo, M uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PD-90-1362C03984nas a2200181 4500008004100000022001400041245011100055210006900166260001600235300001600251490000700267520338400274100002203658700001603680700002003696700002003716856006603736 2012 eng d a0191-291700aFirst Report of Leaf Spot Caused by Phytophthora taxon Pgchlamydo on Evergreen Nursery Stock in California0 aFirst Report of Leaf Spot Caused by Phytophthora taxon Pgchlamyd cJan-11-2012 a1691 - 16910 v963 a

As part of the Phytophthora ramorum testing program from 2005 through 2007, a Phytophthora sp. was isolated on PARP-CMA medium (4) at the CDFA lab in Sacramento, CA, from the margin of necrotic spots and tissue suffering from dieback on Arctostaphylos sp. (manzanita), Camellia spp., Laurus nobilis (bay), Buxus sempervirens (boxwood), Rhododendron sp., Arbutus unedo (strawberry tree), and Sequoia sempervirens (coast redwood). Isolates were collected from Shasta, Contra Costa, San Diego, Solano, Santa Cruz, Alameda, Sacramento, San Joaquin, Monterey, and Los Angeles Counties. Isolates from A. unedo tissue on PARP medium produced apapillate, obovate sporangia 25 to 80 × 15 to 40 μm (48.0 × 26.9 μm average) and a few isolates produced intercalary and terminal chlamydospores at 22°C (30 to 46 μm diameter, 38.9 μm average). The internal transcribed spacer region (ITS) of rDNA was amplified from four isolates using ITS1 and ITS4 primers as described by White et al. (3) and the amplicons sequenced (GenBank Accession Nos. JQ307188 through JQ307191). BLAST analysis of the amplicons showed 99 to 100% identity with the ITS sequence of Phytophthora taxon Pgchlamydo from forest streams in Oregon (GenBank Accession No. HM004224) (1). Pathogenicity tests were performed on B. sempervirens, C. sasanqua, L. nobilis, and A. unedo. Five plants of each species were inoculated with 6-mm plugs taken from the margin of a 7- to 10-day-old culture grown on V8 juice agar. Plant leaves were wounded with a sterile pushpin and two agar plugs were covered with a freezer tube cap filled with sterile dH2O and clipped to the underside of the leaves with a sterile pin-curl clip (4). Inoculated plants were sprayed with water, covered with plastic bags, and incubated for 2 days, when bags and plugs were removed. Five leaves of each isolate plus five control plugs using V8 juice agar alone were inoculated on each plant. Plants were incubated for 12 days at 18°C (16-h photoperiod). Lesions formed on all inoculated plants, ranging in size from approx. 1 mm on B. sempervirens to 9.2 × 10.9 mm average on A. unedo. The lesions on A. unedo grew into and caused the mid-vein to blacken. The lesion sizes on camellia and bay were larger than those formed on B. sempervirens and smaller than those formed on A. unedo, with most lesions surrounded by a dark ring. Phytophthora taxon Pgchlamydo is associated with leaf lesions on rhododendron and dieback of yew in Minnesota (2). To our knowledge, this is the first report of Phytophthora taxon Pgchlamydo causing disease in camellia, bay, strawberry tree, and boxwood in California. Phytophthora taxon Pgchlamydo causes damage that is indistinguishable from the quarantine pest, P. ramorum (4).

References: (1) P. W. Reeser et al. Mycologia 103:22, 2011. (2) B. W. Schwingle and R. A. Blanchette. Plant Dis. 92:642, 2008. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds., Academic Press, San Diego, 1990. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.

1 aBlomquist, C., L.1 aYakabe, L E1 aSoriano, M., C.1 aNegrete, M., A. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-02-12-0221-PDN02465nas a2200277 4500008004100000022001400041245008900055210006900144300000600213520159700219653001901816653001401835653001601849653002401865653002601889653002601915100002201941700002401963700002601987700002302013700001702036700001802053700002002071700002002091856007602111 2012 eng d a1878-614600aFour phenotypically and phylogenetically distinct lineages in Phytophthora lateralis0 aFour phenotypically and phylogenetically distinct lineages in Ph a-3 a

Until recently Phytophthora lateralis was known only as the cause of dieback and mortality of Chamaecyparis lawsoniana in its native range in the Pacific Northwest. Since the 1990s however disease outbreaks have occurred increasingly on ornamental C. lawsoniana in Europe; and in 2007 the pathogen was discovered in soil around old growth C. obtusa in Taiwan, where it may be endemic. When the phenotypes of over 150 isolates of P. lateralis from Taiwan, across the Pacific Northwest (British Columbia to California) and from France, the Netherlands and the UK were compared three growth rate groups were resolved: one slow growing from Taiwan, one fast growing from the Pacific Northwest and Europe and one of intermediate growth from a small area of the UK. Within these growth groups distinct subtypes were identified based on colony patterns and spore metrics and further discriminated in a multivariate analysis. The assumption that the three main growth groups represented phylogenetic units was tested by comparative sequencing of two mitochondrial and three nuclear genes. This assumption was confirmed. In addition two phenotype clusters within the Taiwan growth group were also shown to be phylogenetically distinct. These four phenotypically and genotypically unique populations are informally designated as the Pacific Northwest lineage, the UK lineage, the Taiwan J lineage and the Taiwan K lineage. Their characteristics and distribution are described and their evolution, taxonomic and plant health significance is discussed.

10aColony pattern10aevolution10aGrowth rate10aMultigene phylogeny10aMultivariate analysis10aSporangial morphology1 aBrasier, Clive, M1 aFranceschini, Selma1 aVettraino, Anna Maria1 aHansen, Everett, M1 aGreen, Sarah1 aRobin, Cecile1 aWebber, Joan, F1 aVannini, Andrea uhttp://www.sciencedirect.com/science/article/pii/S1878614612001717?v=s504925nas a2200157 4500008004100000022001400041245012100055210006900176260001600245520435300261100002104614700002404635700002104659700002104680856006604701 2016 eng d a0191-291700aFirst report of Phytophthora gonapodyides causing stem canker on European beech (Fagus sylvatica) in Southern Sweden0 aFirst report of Phytophthora gonapodyides causing stem canker on cNov-05-20173 a

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 Malmö, 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°C in darkness. Growing hyphae were later transferred to PDA media and incubated at 20°C in the dark. The colony pattern was stellate. The average radial growth rate at 20 °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 µm) 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®. 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, ±1.66 vs. 0.4 mm, ±0.01; P<0.0001 for Isolate 1 and 28.9 mm, ±1.42 vs. 0.4 mm, ±0.01; P<0.001 for Isolate 2). Koch’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.

1 aCleary, Michelle1 aGhasemkhani, Marjan1 aBlomquist, Mimmi1 aWitzell, Johanna uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-04-16-0468-PDN04195nas a2200217 4500008004100000245011500041210006900156260001200225300000700237490000700244520345000251653002703701653001803728653002103746100001703767700001403784700002103798700001203819700001303831856013303844 2010 eng d00aFirst report of Phytophthora gonapodyides involved in the decline of Quercus ilex in xeric conditions in Spain0 aFirst report of Phytophthora gonapodyides involved in the declin c12/2010 a330 v223 a

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 Cáceres, 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°58'N 6°5'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 µm) with exit pores of 10-20 µm 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°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°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°C in natural daylight. Three months after inoculation, mortality of infected plants was 53%, and mean survival time (±SD) of infected plants was 71±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±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

10aPhytophthora cinnamomi10asoil moisture10asoil water table1 aCorcobado, T1 aCubera, E1 aPérez-Sierra, A1 aJung, T1 aSolla, A uhttps://forestphytophthoras.org/references/first-report-phytophthora-gonapodyides-involved-decline-quercus-ilex-xeric-conditions02274nas a2200169 4500008004100000245009200041210006900133300001200202490000800214520169100222100002601913700002601939700002501965700002701990700002002017856006702037 2011 eng d00aForest type influences transmission of Phytophthora ramorum in California oak woodlands0 aForest type influences transmission of Phytophthora ramorum in C a492-5010 v1013 a

The transmission ecology of Phytophthora ramorum from bay laurel (Umbellularia californica) leaves was compared between mixed-evergreen and redwood forest types throughout winter and summer disease cycles in central, coastal California. In a preliminary multisite study, we found that abscission rates of infected leaves were higher at mixed-evergreen sites. In addition, final infection counts were slightly higher at mixed-evergreen sites or not significantly different than at redwood sites, in part due to competition from other foliar pathogens at redwood sites. In a subsequent, detailed study of paired sites where P. ramorum was the main foliar pathogen, summer survival of P. ramorum in bay laurel leaves was lower in mixed-evergreen forest due to lower recovery from infected attached leaves and higher abscission rates of infected leaves. Onset of inoculum production and new infections of bay laurel leaves occurred later in mixed-evergreen forest. Mean inoculum levels in rainwater and final infection counts on leaves were higher in redwood forest. Based on these two studies, lower summer survival of reservoir inoculum in bay laurel leaves in mixed-evergreen forest may result in delayed onset of both inoculum production and new infections, leading to slower disease progress in the early rainy season compared with redwood forest. Although final infection counts also will depend on other foliar pathogens and disease history, in sites where P. ramorum is the main foliar pathogen, these transmission patterns suggest higher rates of disease spread in redwood forests during rainy seasons of short or average length.

1 aDavidson, Jennifer, M1 aPatterson, Heather, A1 aWickland, Allison, C1 aFichtner, Elizabeth, J1 aRizzo, David, M uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-03-10-006400431nas a2200121 4500008004100000245005800041210005800099300000800157490000700165100001600172700001900188856010200207 1991 eng d00aFirst report of Phytophthora lateralis on Pacific yew0 aFirst report of Phytophthora lateralis on Pacific yew a9680 v751 aDeNitto, GA1 aKliejunas, J T uhttp://www.apsnet.org/publications/PlantDisease/BackIssues/Documents/1991Abstracts/PD_75_968C.htm04536nas a2200181 4500008004100000022001400041245010700055210006900162260001600231300000900247490000800256520395000264100001604214700002104230700001704251700002004268856006604288 2016 eng d a0191-291700aFirst Report of Phytophthora chlamydospora Causing Root Rot on Walnut (Juglans regia ) Trees in Turkey0 aFirst Report of Phytophthora chlamydospora Causing Root Rot on W cJan-11-2016 a23360 v1003 a

Common or English (Persian) walnut (Juglans regia L.) is an important nut crop in Turkey, which is the fourth largest producer of walnut in the world. In August 2015, we observed sudden wilt and subsequent death associated with root rot. Approximately 15% of 2,000 5- to 7-year-old J. regia cv. Chandler trees grafted on wild walnut (J. regia) in waterlogged areas of a commercial walnut orchard in Bingöl province of eastern Turkey were affected. Most fine roots were completely rotted and the inner bark of infected lateral and taproots showed a reddish brown discoloration. Tissue samples taken from the margins of root lesions of 10 symptomatic trees were placed on grated carrot corn meal agar (GCCMA) (Türkölmez et al. 2015) amended with 5 mg of pimaricin, 250 mg of ampicillin, 10 mg of rifampicin, 100 mg of pentachloronitrobenzene, and 50 mg of hymexazol per liter (P5ARPH). Plates were incubated for 5 days at 28°C in the dark. A Phytophthora species was consistently isolated from the tissues. On GCCMA, colonies had a distinct petaloid growth pattern and produced abundant spherical, thin-walled, intercalary and terminal chlamydospores (30 to 46 μm diameter) and hyphal chains of globose to subglobose swellings. After incubation of mycelial disks in nonsterile soil extracts at 25°C, all isolates produced hyaline, nonpapillate, noncaducous sporangia of ovoid to obpyriform shape, with internal proliferation, measuring 34.5 to 56.5 μm in length, 27.0 to 39.5 μm wide, with a length/breadth ratio of 1.4 to 1.7, formed on unbranched or sympodial sporangiophores. Growth rate on carrot agar (CA) at 25°C was 3.3 to 3.5 mm d−1; the optimum and maximum temperatures for mycelium growth on CA were 29 and 37°C, respectively. All these characteristics were similar to those described for Phytophthora chlamydospora Brasier and Hansen (Hansen et al. 2015), previously known as P. taxon Pgchlamydo. Genomic DNA was extracted from three representative isolates. The internal transcribed spacer (ITS) region of rDNA and cox2 gene regions were amplified using the ITS6/ITS4 and FMPhy10b/FMPhy8b primer pairs, respectively, and sequenced (GenBank accession nos. KU725882, KU725883, KU707216, KX446861, KX446862). BLAST searches of ITS region showed 100% identity to many P. chlamydospora isolates, including the ex-type culture P236 (AF541900) (Brasier et al. 2003), deposited in GenBank and of cox2 gene regions of two isolates had 100% identity with PD_01777_cox2 and PD_00174_cox2 accessions deposited at Phytophthora-ID databases, which confirmed the morphological identification. Pathogenicity of P. chlamydospora was evaluated using the soil infestation method on 10 1-year-old potted J. regia cv. Chandler seedlings by growing P. chlamydospora on sterilized millet seeds for 4 weeks at 29°C and adding infested millet seeds to potting soil at a rate of 3% (w/v). In 10 noninoculated control plants, sterilized millet seeds were added to the potting soil. Both inoculated and control plants were flooded for 24 h at 2 week intervals. All inoculated plants showed severe wilting within a month and necrosis on lateral and taproots and rot on fineroots after 2 months of incubation in a greenhouse where air temperatures ranged from 24 to 30°C, while control plants remained asymptomatic. Koch’s postulates were satisfied after reisolating P. chlamydospora, which was identified morphologically, from symptomatic roots of inoculated plants. P. chlamydospora has been previously recovered from several ornamental and woody species (Blomquist et al. 2012; Brasier et al. 2003; Ginetti et al. 2014), and to our knowledge, this is the first report of P. chlamydospora infection of walnut, which represents a new host for this pathogen.

1 aDerviş, S.1 aTürkölmez, Ş.1 aÇiftçi, O.1 aSerçe, Ç., U. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-03-16-0306-PDN01603nas a2200169 4500008004100000022001400041245011400055210006900169300000700238490000700245520105300252100001801305700001901323700001701342700002001359856005401379 2014 eng d a1179-539500aFirst evidence of genetic-based tolerance to red needle cast caused by Phytophthora pluvialis in radiata pine0 aFirst evidence of geneticbased tolerance to red needle cast caus a310 v443 a

BACKGROUND:Red needle cast (RNC) is a new needle disease of Pinus radiata D. Don (radiata pine) in New Zealand that is causing significant, but as-yet un-quantified, loss of growth and productivity. This foliar disease has recently been attributed to the infection of the needles by Phytophthora pluvialis Reeser, Sutton & E Hansen. Genetic improvement is seen as a possible solution to mitigate the effects of this needle disease on forest productivity.FINDINGS:To quantify the ability of genetics to provide a solution, RNC was assessed on a single clones-within-families genetics trial using two methods: the percentage needle cast that was attributable to red needle cast symptoms; and the percentage needle cast where the causal agent was not clearly identifiable. Both needle cast assessment methods were found to be heritable (h2 0.21-0.31).CONCLUSIONS:Selecting for tolerance to RNC is likely to deliver healthier trees. More assessments across a number of sites and seasons are required to confirm this result.

1 aDungey, Heidi1 aWilliams, Nari1 aLow, Charlie1 aStovold, Graham uhttp://www.nzjforestryscience.com/content/44/1/3100524nas a2200133 4500008004100000245015400041210006900195300001200264490000700276100001800283700001500301700001200316856006200328 2006 eng d00aFirst report on an infestation of Phytophthora cinnamomi in natural oak woodlands of California and its differential impact on two native oak species0 aFirst report on an infestation of Phytophthora cinnamomi in natu a685-6850 v901 aGarbelotto, M1 aHuberli, D1 aShaw, D uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PD-90-0685C04266nas a2200205 4500008004100000022001400041245013800055210006900193260001600262520354900278100002303827700002203850700002103872700001803893700001503911700002103926700002503947700002103972856006703993 2021 eng d a0191-291700aFirst reports of Phytophthora ramorum clonal lineages NA1 and EU1 causing Sudden Oak Death on tanoaks in Del Norte County, California0 aFirst reports of Phytophthora ramorum clonal lineages NA1 and EU cJan-18-20213 a

A year of forest health surveys has led to the first detection of Phytophthora ramorum in Del Norte County followed by the first wildland detection of the EU1 clonal lineage (Grunwald et al. 2009) of this pathogen in California. In July 2019, leaves were sampled from two tanoaks (Notholithocarpus densiflorus) and 16 California bay laurels (Umbellularia californica) in Jedediah Smith State Park in Del Norte County, the northernmost coastal County of California. Leaves displayed lesions normally associated with Sudden Oak Death (SOD) caused by P. ramorum and were discovered during the citizen science-based survey known as SOD Blitz (Meentemeyer et al. 2015). Samples were surface sterilized using 75% Ethanol and plated on PARPH-V8 agar (Jeffers and Martin 1986). After plating, DNA was extracted and amplified using two P. ramorum-specific assays (Hayden et al. 2006, Kroon et al. 2004). Leaves from two tanoaks exhibiting twig die-back had typical SOD lesions along the midvein, gave positive PCR results and yielded cultures with colony morphology, sporangia and chlamydospores typical of the NA1 lineage of P. ramorum originally isolated in California from tanoaks and coast live oaks (Quercus agrifolia) (Rizzo et al. 2002). The ITS locus and a portion of the Cox-1 locus were sequenced from DNA extracts of each culture using primers DC6-ITS4 (Bonants et al. 2004) and COXF4N-COXR4N (Kroon et al. 2004), respectively. ITS sequences (GB MN540639-40) were typical of P. ramorum and Cox-1 sequences (GB MN540142-3) perfectly matched the Cox-1 sequence of the NA1 lineage (GB DQ832718) (Kroon et al. 2004). Microsatellite alleles were generated as described in Croucher et al. (2013) for the two Del Norte cultures and for eight P. ramorum cultures, representative of the four main multilocus genotypes (MLGs) present in California, namely c1 (Santa Cruz/Commercial Nurseries), c3 (San Francisco Bay Area), c2 (Monterey County), and c4 (Humboldt County) (Croucher et al. 2013). The two Del Norte MLGs were identical to one another and most similar to MLG c1, with a single repeat difference at a single locus. SSR results suggest the inoculum source may not be from Humboldt County, neighboring to the South, but from a yet unidentified outbreak, possibly associated with ornamental plants. Jedediah Smith State Park was surveyed for 12 months following the initial detection, however the pathogen has yet to be re-isolated in that location. In July 2020, SOD symptomatic leaves from two tanoak trees exhibiting twig cankers were collected 8 Km north of Jedediah Smith State Park, where three additional tanoak trees displayed rapidly browned dead canopies consistent with late stage SOD. Leaves were processed as above. Colonies from these samples produced chlamydospores and sporangia typical of P. ramorum on PARPH-V8 agar, but displayed a growth rate faster than that of NA1 genotypes and were characterized by aerial hyphae, overall resembling the morphology of EU1 lineage colonies (Brasier 2003). The EU1 lineage was confirmed by the perfect match of the sequence of a portion of the Cox-1 gene (GB MW349116-7) with the Cox-1 sequence of EU1 genotypes (GB EU124926). The EU1 clonal lineage has been previously isolated from tanoaks in Oregon forests, approximately 55 Km to the North (Grünwald et al. 2016), but this is the first report for California wildlands and will require containment and government regulations. It is unknown whether the EU1 strains in Del Norte County originated from Oregon forests or elsewhere.

1 aGarbelotto, Matteo1 aDovana, Francesco1 aSchmidt, Douglas1 aChee, Cameron1 aLee, Chris1 aFieland, Valerie1 aünwald, Niklaus, J.1 aValachovic, Yana uhttps://apsjournals.apsnet.org/doi/10.1094/PDIS-12-20-2633-PDN04137nas a2200169 4500008004100000022001400041245012400055210006900179260001600248300001600264490000700280520356000287100001803847700001603865700002003881856006603901 2010 eng d a0191-291700aFirst Report of Collar and Root Rot Caused by Phytophthora tentaculata on Witloof Chicory (Cichorium intybus ) in Italy0 aFirst Report of Collar and Root Rot Caused by Phytophthora tenta cJan-12-2010 a1504 - 15040 v943 a

Witloof chicory (Cichorium intybus L.) is an important crop in Italy where most of the crop is still produced in soil. In September 2009, chicory plants (cv. Pan di Zucchero) grown on a commercial farm in Tarquinia (central Italy) showed symptoms of a previously unknown disease. Symptoms, observed 20 days after transplanting, consisted of stunting, yellowing of leaves, and a crown and root rot. Affected plants turned brown, wilted, and eventually died. At the soil level, dark brown-to-black water-soaked lesions coalesced and often girdled the stem. All of the crown and root system was affected. At this location, the disease was severe and widespread, with 60% of observed plants being affected. A Phytophthora-like organism was consistently isolated on a medium selective for oomycetes (4) after disinfestation of lower stem and root pieces of C. intybus for 1 min in a solution containing 1% NaOCl. Tissue fragments of 1 mm2 were excised from the margins of the root and crown lesions. The pathogen genus was identified as Phytophthora based on morphological and physiological features. Sporangia were produced for identification by growing a pure culture for 15 days on modified V8 juice agar medium (Campbell V8 juice [200 ml], agar [15 g], CaCo3 [0.5 g], and sterile water [800 ml]) under alternating light and dark (12/12 h). Sporangia were pyriform to ovoid, papillate, and measured 33.3 to 59.2 × 18.9 to 30.2 μm (average 39.9 × 25.8 μm). Chlamydospores developed in 28-day-old cultures and measured 21.3 to 30.2 × 19.5 to 29.7 μm (average 24.4 × 23.6 μm). Oogonia were globose and measured 26 to 41 μm (average 32.5 μm). Eighty percent of antheridia were paragynous. Amphyginous antheridia (15 to 20%) were also observed. Oospores were scarcely produced and measured 24 to 32 μm in diameter. The internal transcribed spacer (ITS) region of rDNA of a single isolate was amplified using the primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 851-bp segment showed 100% homology with the sequence of Phytophthora tentaculata. The nucleotide sequence has been assigned GenBank Accession No. GU949536. Pathogenicity of this isolate was confirmed by inoculating C. intybus cv. Pan di Zucchero plants 20 days after transplant. The same isolate was grown for 15 days on a mixture of 70:30 wheat/hemp kernels and then 5 g/liter of the inoculum was mixed into a substrate containing a mixture of blond and black peat (15:85 vol/vol), pH 5.5. Five plants per 2-liter pot were transplanted and four replicates were carried out. Twenty noninoculated plants represented the control treatment. The trial was repeated. Plants were kept in two growth chambers at two temperatures (20 and 25°C). Symptoms similar to those observed in the field developed 7 days after inoculation. Twenty days later, 100 and 40% of the plants were dead at 25 and 20°C, respectively. Control plants remained symptomless. P. tentaculata was consistently reisolated from symptomatic plants. To our knowledge, this is the first report of P. tentaculata on C. intybus in the world (http://nt.ars-grin.gov/fungaldatabases/index.cfm). P. tentaculata was recently reported on lavender in Spain (2) and oregano in Italy (3). The economic importance of this disease is relatively low on most commercial farms.

1 aGaribaldi, A.1 aGilardi, G.1 aGullino, M., L. uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-03-10-020604121nas a2200193 4500008004100000022001400041245012900055210006900184260001200253300001400265490000700279520349100286100001603777700001903793700001503812700001403827700001603841856007003857 2014 eng d a0191-291700aFoliar Blight and Shoot Dieback Caused by Phytophthora ramorum on Viburnum tinus in the Pistoia Area, Tuscany, Central Italy0 aFoliar Blight and Shoot Dieback Caused by Phytophthora ramorum o c03/2014 a423 - 4230 v983 a

In spring 2013, pot-grown Viburnum tinus plants shipped to an ornamental nursery in Pescia (Pistoia, central Italy, 287 m a.s.l., 43°54′0″ N, 10°41′0″ E) from another local nursery were found to bear disease symptoms. Symptoms included brown to black foliar lesions, later expanding into larger blotches; necrosis of the petioles; shoot wilting and folding; browning of the stems; and necrosis of the cambium. Infected leaves, shoots, and entire plants eventually died. Tissue samples (2 mm2) were cut at the edge of active lesions from tissue of the phloem, the xylem, and the leaves and plated on selective PARPNH V8 agar (V8A) (1). Rose-shaped and finely lobed cottony colonies arose in 2 to 3 days. Mono-hyphal colonies were isolated and transferred to V8A. Square colony pieces (1 cm2) from isolates SB05a and SB05b were placed in filtered pond water after 5 to 7 days. Semipapillate, caducous sporangia with a rounded or conical base were produced within 24 h, individually or in pairs, on each sporangiophore. Sporangia (n = 30 per isolate) were examined: they were 56.2 ± 9.5 × 29.3 ± 4.3 μm (l:b ratio 1.9 ± 0.3). Exit pores averaged 7.0 ± 1.0 μm. Sporangia were ellipsoid (30%), lemon-shaped (28.3%), ovoid (20%), obovoid (16.7%), ampulliform (3.3%), or “peanut-like” (1.7%). Globose chlamydospores, borne intercalarly or terminally, were abundant on both V8A and carrot agar (CA), and were on average 54.7 ± 8.5 μm. Mono-hyphal isolates incubated for 7 days at 23°C were also transferred to CA, corn meal agar (CMA), malt extract agar (MEA), potato dextrose agar (PDA), and V8A. Colonies on these media were identical in shape and appearance to those described in previous reports (2,4). Isolates were identified as Phytophthora ramorum Werres, De Cock & Man in't Veld (4) on the basis of colony type; size, the average l:b ratio and shape of sporangia; and the type and size of the chlamydospores. Isolates were found to be the A1 mating type by pairing them with P. cryptogea BBA 63651 (mating type A2). PCR-amplification of the rDNA ITS region with specific primers Ph1/Ph4 (3) gave fragments of the expected size (GenBank Accession Nos. KF181162 and KF181163). A BLAST search of these ITS sequences in the database found that isolates of P. ramorum were the closest phylogenetically with 100% homology (YQ653034 and HM004221). Pathogenicity tests were conducted on 16 detached V. tinus leaves. A small cut was made aseptically on each of the leaf surfaces and a V8A disc (0.5 cm Ø) with mycelium was placed over the wounds. Control leaves received only sterile V8A discs. Inoculated and control leaves were incubated at 23°C in the dark. Necrotic areas (average 3.5 ± 1.3 cm2) arose on inoculated leaves after 6 days. Control leaves had no symptoms. Re-isolations on PARPNH V8A confirmed P. ramorum as the causal agent. P. ramorum was reported in Italy in 2003 on the exotic Rhododendron yakushimanum (2). This is the first report of the pathogen on a native species (V. tinus) in this country. The Pistoia area is important for nursery gardens and flowers. P. ramorum, which probably arrived on infected plant material, could compromise the export/import trade in stock plants. For this reason, the plant protection services were promptly alerted and the infected plants were destroyed.

1 aGinetti, B.1 aCarmignani, S.1 aRagazzi, A1 aWerres, S1 aMoricca, S. uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-13-0767-PDN03912nas a2200169 4500008004100000022001400041245007100055210006900126260001200195300000800207490000700215520340000222100002203622700002403644700002303668856005103691 2013 eng d a0191-291700aFirst Report of Phytophthora Taxon Walnut in Lombardy, North Italy0 aFirst Report of Phytophthora Taxon Walnut in Lombardy North Ital c03/2014 a4240 v983 a

The park Boscoincittà, Milan, North Italy (136 m a.s.l., 45º 29' 06" N, 9º 5' 32" E) has an area of 110 hectares and includes tree stands, wood clearings, trails and watercourses. Recently, common walnut (Jugland regia) trees in the park have begun to suffer from a progressive dieback that has caused roughly 90% mortality. Aerial symptoms were: stunted growth, loss of vigor, crown thinning and bark cankers with tarry exudates on the lower stem. The xylem tissue of trees showed large necrosis and flame-shaped discolouration below the bark. Since the dieback seemed caused by Phytophthora, samples were taken from 3 symptomatic trees and, by baiting, from the nearby soil and watercourses. Isolations from apple baits were carried out after a week. Isolations taken from tissue at the edge of active lesions of the trees were transferred on the selective medium V8A-PARPNH (1) and incubated at 24ºC. Cottony colonies appeared after 3 days and single hyphal tip derivatives were transferred to V8A for a further 4-7 days. Fragments (1 cm2) of mycelium of the subcultured colonies were then placed in filtered (Ø 0.22 μm nitrocellulose filters, Millipore) pond water. Three isolates were retrieved within 24 h, 2 from tree tissue and one from water. These produced ovoid, non-papillate sporangia (Fig A), thirty of which per isolate were measured. Sporangia averaged 52.5 ± 9.6 x 32.9 ± 4.7 µm (range 30.8 – 67 x 22.5 – 42.8) with a l:b ratio of 1.59 ± 0.19 (range 1.27 – 2.05), and exit pores of 11.1 ± 1.7 µm (range 7.31 – 14.21). External proliferation from previously emptied sporangia and hyphal swellings were observed on V8A. On V8A, colonies had optimal growth at 32°C (5.7 ± 0.8 mm d-1) with a maximum at 37°C. Colonies had a chrysanthemum-shaped, scanty fluffy aspect on PDA (Fig B). Isolates were identified as Phytophthora taxon walnut on the basis of macro- and micro-morphology and sequence information from the ITS-rDNA region, that was amplified with primers ITS6 and ITS4 (2) after DNA extraction with a commercial kit (Sigma Aldrich). A region of the cox1 gene of isolate B164 was also amplified with primers OomCoxILevup and Fm85mod (3) and sequenced (GenBank acc. no. KC291584) but this was irrelevant for identification purposes because that gene region has not been sequenced for other isolates of this taxon. A BLAST search in GenBank and the Phytophthora database revealed a 99% identity of the ITS-rDNA from our isolate B164 (GenBank acc. no. KC291550) with the P. taxon walnut isolate P532 (AF541910) (4). Inoculation trials were conducted on 10 detached leaves. A little lesion was produced with a sterile scalpel on the lower leaf surfaces and a 0.5 cm Ø agar plug was placed over the wounds. Necrotic lesions averaged 3.7±1.6 x 2.0±0.5 cm after 1 week of incubation at 20°C in the dark (Fig C). Control leaves showed no symptoms. Reisolations on V8-PARPNH agar confirmed P. taxon walnut as the causal agent. Members of the Phytophthora genus grouping with the P. taxon walnut in clade 6 are mainly reported as saprophytes or pathogens from riparian ecosystems and forests (4). This is the first report of P. taxon walnut from Italy. Since the oomycete proved in our growth trial to be distinctly thermophilic, we hypothesize that its spread is being favored by the rising temperatures observed during the last decades in the area.

1 aGinetti, Beatrice1 aRagazzi, Alessandro1 aMoricca, Salvatore uhttp://dx.doi.org/10.1094/PDIS-07-13-0766-PDN 00504nas a2200145 4500008004100000245006100041210006000102260006400162300001000226490002300236100001500259700001500274700001600289856005300305 2012 eng d00aFlorida Citrus Pest Management Guide: Brown Rot of Fruit0 aFlorida Citrus Pest Management Guide Brown Rot of Fruit bUniversity of Florida, IFAS Extension, Gainesville, Florida a2 pp.0 vPublication PP-1481 aGraham, JH1 aTimmer, LW1 aDewdney, MM uhttp://edis.ifas.ufl.edu/pdffiles/CG/CG02200.pdf03561nas a2200217 4500008004100000022001400041245009700055210006900152260001600221300001600237490000800253520289300261100002203154700001903176700001903195700001903214700001603233700001403249700001403263856006603277 2016 eng d a0191-291700aFirst Report of the EU1 Clonal Lineage of Phytophthora ramorum on Tanoak in an Oregon Forest0 aFirst Report of the EU1 Clonal Lineage of Phytophthora ramorum o cJan-05-2016 a1024 - 10240 v1003 a

Initially reported in California as the causal agent of sudden oak death (SOD), efforts to limit spread of Phytophthora ramorum in Oregon natural forests have concentrated on quarantine regulations and eradication of the pathogen from infested areas. P. ramorum has four clonal lineages: NA1; NA2; EU1; and EU2 (Grünwald et al. 2012; Van Poucke et al. 2012). Forest infestations in Oregon have been limited to the NA1 clonal lineage, whereas EU1, NA1, and NA2 clonal lineages have all been found in U.S. nurseries (Kamvar et al. 2015; Prospero et al. 2007). In February 2015, in response to an aerial survey, P. ramorum was isolated from a dying Notholithocarpus densiflorus tree in the South Fork Pistol River drainage of Curry Co., Oregon. The isolated strain was identified as P. ramorum based on presence of chlamydospores, characteristic hyphae, and sporangial morphology. Microsatellite genotyping at 14 loci (Vercauteren et al. 2011) and comparison with reference cultures revealed that these isolates belonged to the EU1 clonal lineage. Subsequently, five more isolates were obtained from the original tree stump and the EU1 lineage was confirmed. Microsatellite alleles of the forest EU1 isolates were nearly identical to EU1 isolates collected in 2012 from a nearby nursery during routine P. ramorum nursery monitoring, except for one allele at locus PrMS145a. Interestingly, several isolates differed at locus ILVOPrMS131a within both the 2015 forest and the 2012 nursery findings with identical allele frequencies in each population for this locus. These data provide inconclusive support for the introduction of EU1 into Curry Co. from the 2012 populations found in nurseries, given that no direct match was found probably owing to the paucity of EU1 samples from nurseries. These results provide further evidence that multiple distinct P. ramorum introduction events into the Curry Co. forest are a critical component of the epidemic (Kamvar et al. 2015). The impact of the EU1 clonal lineage of P. ramorum on Oregon natural forests is uncertain, but it may result in potential sexual reproduction given that EU1 is of A1 mating type while the prior population consisted of NA1 A2 mating type individuals. While sexual populations of P. ramorum have not been observed in nature or were aberrant in the laboratory, the presence of both A1 and A2 mating types makes the potential for sexual recombination more likely. The EU1 forest infestation is undergoing eradication treatments. Additional monitoring is necessary to determine if the EU1 clonal lineage occurs elsewhere in Curry Co. forests.

1 aGrünwald, N., J.1 aLarsen, M., M.1 aKamvar, Z., N.1 aReeser, P., W.1 aKanaskie, A1 aLaine, J.1 aWiese, R. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-10-15-1169-PDN03302nas a2200169 4500008004100000022001400041245005900055210005900114260001600173300001400189490000700203520279100210100001903001700002503020700002103045856006603066 1999 eng d a0191-291700aFirst Confirmation of Phytophthora lateralis in Europe0 aFirst Confirmation of Phytophthora lateralis in Europe cJan-06-1999 a587 - 5870 v833 a

Phytophthora lateralis, a pathogen of Chamaecyparis lawsoniana (Port-Orford cedar or Lawson's cypress), was confirmed in France, but isolates from Germany identified as P. lateralis or “similar to” P. lateralis proved to be P. gonapodyides. Previously, P. lateralis was known only from western North America, where it has been destructive in nurseries, ornamental plantings, and the forest since its introduction about 1920 (1). Reports from other locations have proved to be misidentifications or impossible to confirm. In France, P. lateralis was isolated and identified from C. lawsoniana on two occasions (1996 and 1998) in different parts of the country, probably stemming from a single original infestation of young, potted, greenhouse-propagated cedars in a commercial nursery. German isolates were from an old culture collection and from irrigation water in a nursery growing a wide range of woody ornamentals. Identifications were confirmed by comparison (2) with authentic isolates. P. lateralis isolates from France and Oregon formed laterally proliferating, elongated obpyriform sporangia that under the conditions of our tests could be dislodged by agitation, leaving a short pedicel. Also, brown chlamydospores formed laterally on the hyphae or terminally on a short stalk and oospores were not formed on standard media. Radial growth was about 2 mm per day. In contrast, sporangia of German isolates and known P. gonapodyides isolates were similar. They exhibited nested pro liferation, were broader than P. lateralis sporangia, and were not readily dehiscent. Some P. gonapodyides isolates, including those from Germany, formed chlamydospores, but these were nearly all catenulate and not lateral, and isolates grew faster (3 to 4 mm per day). Pathogenicity was tested by stem inoculation of C. lawsoniana. P. lateralis from France and Oregon produced lesions averaging 4.7 cm after 2 months (range 2.0 to 8.1 cm, six replicates per isolate, five isolates) while the six replicates of the two German isolates averaged 1.2- and 1.6-cm lesion lengths. Furthermore, sequences of internal transcribed spacer (ITS) DNA from French and Oregon P. lateralis isolates were identical, while sequences of German isolates were similar to P. gonapodyides (J. Duncan and D. Cooke, personal communiation). P. lateralis is a dangerous pathogen of C. lawsoniana and is also pathogenic to Taxus spp. (1), although less aggressive on this host. If established, it would be a serious threat to the widespread ornamental plantings and scattered forest plantations of C. lawsoniana in Europe.

1 aHansen, E., M.1 aStreito, Jean-Claude1 aDelatour, Claude uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS.1999.83.6.587B04195nas a2200193 4500008004100000022001400041245012200055210006900177260001600246300001400262490000700276520357100283100001903854700001503873700001403888700001603902700001703918856006603935 2015 eng d a0191-291700aFirst Report of Phytophthora pluvialis Causing Needle Loss and Shoot Dieback on Douglas-fir in Oregon and New Zealand0 aFirst Report of Phytophthora pluvialis Causing Needle Loss and S cJan-05-2015 a727 - 7270 v993 a

Douglas-fir (DF, Pseudotsuga menziesii) is the most important forest tree in Oregon and is the second most valuable conifer in New Zealand. Phytophthora pluvialis was described (Reeser et al. 2013) from mixed evergreen forests in southwest Oregon. It was subsequently identified as the cause of red needle cast of radiata pine in New Zealand (Dick et al. 2014). There it was also isolated from chlorotic DF needles that dislodged readily from trees growing close to diseased radiata pine. In spring 2014, raintraps baited with rhododendron leaves were paired with nine 2-year-old DF seedlings at three or four locations in each of three 20- to 30-year-old DF plantations in western Oregon (11 raintraps and 99 seedlings total); control raintraps and seedlings were at two sites with no overstory (two raintraps and 18 seedlings total). Baits were collected at 2-week intervals and plated in corn meal agar (CMA) amended with natamycin, ampicillin, and rifamycin SV (CARP, Reeser et al. 2013). Symptomatic tissues from the seedlings were surface disinfested and plated in CARP. P. pluvialis was identified by sequencing the mitochondrial cox spacer region. Zoospores or sporangia produced from Oregon DF isolate 3661-NDL-041514 (GenBank KM491217) were used to inoculate four 2-year-old DF seedlings. Sporangia were induced by flooding cultures grown in pea broth with filtered stream water; zoospore release was stimulated by chilling. About 20 ml of inoculum was applied to DF seedlings using an airbrush sprayer. Two control seedlings were sprayed with filtered stream water. Inoculum contained 200 to 300 sporangia/ml or 5 × 104 zoospores/ml. Inoculated trees were enclosed in polyethylene bags for 48 h with supplemental mist and incubated in a growth chamber at 16 to 18°C with 12-h photoperiod. Symptomatic tissues were collected starting at 14 days, surface disinfested, and plated in CARP. Isolates were collected and identified as above. P. pluvialis was isolated from baits in nine of the 11 raintraps and from 54% of seedlings across all three plantations. All isolations from control sites were negative. Overstory trees exhibited thin crowns from needle loss. Symptoms on seedlings included partial needle loss of 1- and 2-year-old needles and irregular mottled needle chlorosis. P. pluvialis was isolated from needles on 54% of the seedlings associated with positive raintraps. Isolation success from individual symptomatic needles from locations where raintraps were positive was ∼13%. Twig symptoms were not visible on overstory trees, but trees were not felled for close examination. Twig symptoms on seedlings included tip dieback and stem lesions extending from bud scars. Twig symptoms developed on 37% of seedlings from locations with positive raintraps; P. pluvialis was isolated from 47% of these twig lesions. Needle and twig symptoms similar to those on naturally infected seedlings developed on artificially inoculated seedlings and P. pluvialis was isolated from seedlings inoculated with both sporangia and zoospores, but not from control seedlings. This is the first report of a foliar Phytophthora species on DF. There is as yet little information on epidemiology or impact in the forest in Oregon. In New Zealand, DF defoliation was most evident in plantations growing close to radiata pine plantations on sites prone to red needle cast.

1 aHansen, E., M.1 aReeser, P.1 aSutton, W1 aGardner, J.1 aWilliams, N. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-09-14-0943-PDN00444nas a2200133 4500008004100000245005900041210005900100300001200159490000700171100001600178700002500194700002100219856007000240 1999 eng d00aFirst confirmation of Phytophthora lateralis in Europe0 aFirst confirmation of Phytophthora lateralis in Europe a587-5870 v831 aHansen, E M1 aStreito, Jean-Claude1 aDelatour, Claude uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.1999.83.6.587B04067nas a2200193 4500008004100000022001400041245008700055210006900142260001200211300000800223490000700231520345300238100002903691700003003720700002203750700002703772700002303799856005103822 2013 eng d a0191-291700aFirst report of Phytophthora plurivora causing collar rot on common alder in Spain0 aFirst report of Phytophthora plurivora causing collar rot on com c03/2014 a4250 v983 a

Phytophthora decline of riparian alder (Alnus spp.) has been reported in several European countries. Death of common alder (Alnus glutinosa) due to Phytophthora alni has also been reported in Spain. During several surveys of alder trees in September 2012, typical die-back symptoms, including sparse small yellowish foliage and the presence of rusty exudates on the bark at the collar and lower stem were observed in A.glutinosa growing on the banks of the river Tera (Langa de Duero, Soria, 41°36′34″N, 3°25′10″W, elevation 851 m) and the river Tormes (La Maya, Salamanca, 40°41′42″N, 5°35′36″W, elevation 833 m). Bark samples plus cambium were taken from the active lesions at collar region, cut into small pieces, dried on filter paper and plated on V8-PARPH agar. The samples were incubated for four days at 20 °C in the dark before obtaining the Phytophthora isolates. Colonies developed on V8 juice agar (V8A) had limited aerial mycelium at the centre and displayed radiate and slightly chrysanthemum-like growth pattern. Mycelial growth was optimal at 25 °C (radial growth rate, 8.2 mm d-1), whereas no growth was observed at 32 °C. Isolates were homothallic with paragynous antheridia, smooth-walled spherical (very rarely elongated) oogonia (22.8–30.6 μm diam.) and both plerotic and aplerotic golden brown oospores (21.3–28.5 μm diam.). In non sterile soil extracts, the isolates produced abundant sporangia (31.5–57.2 × 21.3–38.4 μm; length:breadth ratio 1.2 to 1.6) borne terminally on unbranched or sympodial sporagiophores, occasionally attached laterally to the sporangiophores. Sporagia were non-caducous, semipapillate, mainly ovoid and obpyriform, obovoid to limoniform but sometimes distorted with two apices. On the basis of the morpho-physiological features, the isolates resembled P. plurivora (formerly identified as P. citricola). To confirm this, genomic DNA was extracted and subjected to Polymerase Chain Reaction (PCR). The internal transcribed spacer (ITS) region of the rDNA was amplified using the ITS-6 (5’ GAA GGT GAA GTC GTA ACA AGG 3’) and ITS-4 (5’ TCC TCC GCT TAT TGA TAT GC 3’) primers before sequencing (Secugen, Madrid, Spain). The sequences were deposited in the EMBL/GenBank database (GenBank Accession No. KF413074 and KF413075). In order to perform the pathogenicity test, 10 A. glutinosa seedlings (two-year-old) per isolate were inoculated by using the under bark inoculation technique and 10 control seedlings were inoculated with V8A. Seedlings were incubated in a growth chamber at 22.5 ºC with a 14-h photoperiod. Three months after inoculation, all inoculated plants wilted and died, whereas the control plants showed no disease symptoms. To fulfil Koch’s postulates, the pathogen was re-isolated from the necrotic lesions developed around inoculation points, thus confirming its pathogenicity. Phytophthora plurivora has been found to be present in rhizosphere soil beneath Alnus spp. and to cause aerial canker and collar rot on alder trees in Austria, Germany and Romania. Further studies and surveys are essential to determine the distribution, extent of damage and potential interactions with other alder pathogens (e.g. P. alni). To our knowledge, this is the first record of P. plurivora affecting A. glutinosa in Spain.

1 aHaque, Mohammed Masum Ul1 aMartínez-Álvarez, Pablo1 aLomba, María, é1 aMartín-García, Jorge1 aDiez, Julio Javier uhttp://dx.doi.org/10.1094/PDIS-07-13-0784-PDN 02334nas a2200181 4500008004100000022001400041245007700055210006900132260001600201300001400217490000700231520175200238100002101990700002302011700001702034700002102051856008002072 2021 eng d a0032-086200aFitness characteristics of the European lineages of Phytophthora ramorum0 aFitness characteristics of the European lineages of Phytophthora cOct-12-2020 a275 - 2860 v703 a

As an introduced pathogen, Phytophthora ramorum exists as four near‐clonal evolutionary lineages, of which only EU1 and EU2 are established in the UK. EU1 has become widespread since the first findings in 2002 whereas EU2, detected in 2011, has a more limited distribution. Both lineages are epidemic in plantation‐grown larch, sporulating asexually on needles, but also causing heavy dieback and mortality. To understand whether EU1 and EU2 pose different threats to forest health, we compared their growth characteristics on agar, pathogenicity on several hosts, and sporulation on Japanese larch needles. When pathogenicity was evaluated by measuring colonization at 20 °C in mature bark (phloem) of Japanese and European larch (Larix kaempferi and L. decidua), English oak (Quercus robur), and beech (Fagus sylvatica), Japanese larch was the most susceptible and oak the least susceptible. On average, EU2 isolates produced significantly larger lesions than EU1 isolates in Japanese larch and oak although not in the other hosts. With tests using young saplings of Japanese and European larch, damaging bark lesions formed at both 10 °C and 20 °C, but EU2 was significantly more pathogenic at 20 °C on both hosts compared with EU1. In contrast, both lineages caused similar amounts of necrosis on inoculated leaves of rhododendron (Rhododendron ponticum). Moreover, EU2 isolates usually sporulated less abundantly on larch needles compared with EU1 isolates, suggesting a trade‐off in pathogenicity and sporulation between lineages. As EU2 tends to have smaller sporangia than EU1, this could also reduce the inoculum potential of EU2.

1 aHarris, Anna, R.1 aBrasier, Clive, M.1 aScanu, Bruno1 aWebber, Joan, F. uhttps://bsppjournals.onlinelibrary.wiley.com/doi/abs/10.1111/ppa.13292?af=R03940nas a2200181 4500008004100000022001400041245012500055210006900180260001200249300001600261490000700277520334300284100001403627700001303641700001703654700001703671856007003688 2014 eng d a0191-291700aFirst Report of Phytophthora hedraiandra Causing Rhododendron Dieback and Root Rot of Common Beech in the Czech Republic0 aFirst Report of Phytophthora hedraiandra Causing Rhododendron Di c10/2014 a1434 - 14340 v983 a

From 2010 to 2012, Phytophthora isolates were obtained from brownish diffusion leaf lesions usually up to 2 to 3 cm in diameter of Rhododendron caucasicum ‘Cheer,’ from withered twigs of Rhododendron sp. with blackish elongated lesions up to ~5 cm in length, and from rotten feeder roots of 2-year-old, chlorotic, wilting seedlings of Fagus sylvatica collected from ornamental and forest nurseries in three areas (central and eastern Bohemia and northern Moravia) in the Czech Republic. Isolates formed chrysanthemum-like to slightly stellate, appressed colonies with sparse aerial mycelium on V8 agar (V8A) plates at 20°C after 5 days, whereas on carrot agar (CA) plates the pattern was vague with no aerial mycelium. The cardinal growth temperatures were: min. 3°C, optimum 23 to 27°C, and max. 31°C. Radial growth was 5.7 to 6.6 mm/day at 20°C on V8A. The isolates were homothallic and produced colorless, smooth-walled, spherical oogonia with an average diameter 29.9 to 33.8 μm on CA. Oospores were aplerotic (avg. 26.4 to 29.3 μm), oospore wall was hyaline and averaged 1.3 to 1.7 μm thick, oospore wall index was 0.26 to 0.32. Paragynous or occasionally amphigynous antheridia averaged 13.4 to 15.0 × 10.9 to 12.5 μm (height × width). Sporangia were caducous, papillate, globose, spherical to ovoid, with short pedicels (avg. 2.1 to 2.6 μm) and averaged 30.9 to 41.5 × 25.5 to 30.6 μm, L:B ratio was 1.2 to 1.4. Chlamydospores were not observed. Morphological characters resembled those described for P. hedraiandra (1). The isolates were deposited in the collection of phytopathogenic oomycetes of RILOG Pruhonice and given accession nos. 450.11, 531.11, and 578.12. The isolates were sequenced for nuclear rDNA ITS region and partial Cox I gene. Obtained sequences were compared with sequences present in GenBank database using BLAST. The ITS sequences of all isolates (GenBank Accession Nos. KJ567081, 82, and 83) of overall length of 792 bp were identical to that of P. hedraiandra AY707987 (1). The Cox I sequences of overall length of 880 bp (KJ567084, 85, and 86) showed 99% homology (1 bp substitution) with AY769115 (1) and 100% identity with other Cox I sequences of P. hedraiandra, i.e., JN376067 (4) and EF174432 (3). Koch's postulates were confirmed by wound-inoculating of 3-year-old rhododendron and common beech plants (10 host plants per corresponding isolate). Rhododendron leaves were gently abraded near the midrib, whereas 5-mm-diameter bark plugs were removed from the beech collars. The inoculum (5-mm-diameter V8A plug with actively growing mycelium) was placed over wounds and sealed with Parafilm. Control plants were treated in the same manner with sterile agar plugs. Plants were maintained in a greenhouse at 22°C. All inoculated plants showed disease symptoms after 10 days of incubation; the lesions were up to 2 cm in rhododendron leaves and ~1 cm in beech collars. Control plants remained healthy. The pathogen was re-isolated from all infected plants. To our knowledge, this is the first report of P. hedraiandra in the Czech Republic. Besides it, the pathogen was found in southern and western Europe (Italy, Slovenia, Spain, the Netherlands) and in the United States (2)

1 aHejna, M.1 aCerny, K1 aHavrdova, L.1 aMrazkova, M. uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-04-14-0339-PDN04023nas a2200157 4500008004100000245013300041210006900174300001400243490000700257520349600264100001503760700001203775700001403787700001403801856005003815 2012 eng d00aFirst report of Phytophthora cambivora causing leaf and stem blight and root rot on Taiwan cherry (Prunus campanulata) in Taiwan0 aFirst report of Phytophthora cambivora causing leaf and stem bli a1065-10650 v963 a

Taiwan cherry or Formosan cherry (Prunus campanulata Maxim.) is a beautiful ornamental tree that is native to Taiwan. In spring 2005, a severe disease was observed on 1- to 3-year-old seedlings of Taiwan cherry in a garden in Tungshih, Taichung, Taiwan. Infected plants showed symptoms of greenish water-soaked spots on leaves that became dark brown, 2 to 3 cm in diameter. Infected leaves withered and fell to the ground in 3 to 5 days and young shoots showed symptoms of withering and drooping. Infected roots showed symptoms of necrosis. Severely infected plants eventually died. A Phytophthora sp. was isolated consistently from diseased samples of Taiwan cherry and associated soil. Six isolates of Phytophthora, of the A1 mating type (1), were isolated from single zoospores. Two of these isolates, Tari 25141 (deposited as BCRC34932 in Bioresource Collection and Research Center, Shinchu, Taiwan) and Tari 25144 (BCRC34933), were used for pathogenicity tests on 1-year-old seedlings of Taiwan cherry to fulfill Koch’s postulates. Inoculation was done by placing a cotton swab containing zoospore suspension on leaves or stem, or by soaking seedlings in the zoospore suspension. Inoculated seedlings were kept in a greenhouse at 20 to 25°C for 30 days and examined for appearance of symptoms. Results showed that both isolates were pathogenic on seedlings of Taiwan cherry, causing symptoms similar to those observed on naturally infected seedlings. The temperature range for growth of the six isolates of Phytophthora was 8 to 32°C with optimum temperature at 24°C. The linear growth rate was 72 mm per day on V8A culture (5% V8 vegetable juice, 0.02% CaCO3, and 2% Bacto agar) at 24°C. The colonies on potato dextrose agar produced sparse aerial mycelia with conspicuous radiate patterns. Sporangia were sparse on V8A agar blocks, but abundant when the agar blocks were placed in water under continuous white fluorescent light (average 2,000 lux) for 2 days. Sporangiophores branched sympodially. Sporangia were pear shaped, nonpapillate and nondeciduous, 50 to 75 (62) × 30 to 48 (40) μm, with a length/width ratio of 1.2 to 2.2 (1.6). New internal nested proliferate sporangia were formed inside the empty sac of old matured sporangia after releasing zoospores. No chlamydospores were formed on V8A. Hyphal swellings with distinctive irregular catenulation were produced on V8A and in water. The pathogen was stimulated to form its own oospores by the A2 tester using the method described by Ko (1). Oogonia were 28 to 50 (40) μm in diameter with smooth or irregularly protuberant walls. Oospores were mostly aplerotic and 18 to 42 (31) μm in diameter. Antheridia were amphigynous, mostly two-celled, and 10 to 42 (29) × 12 to 24 (19) μm. The sequence of the internal transcribed spacers (ITS) region of nuclear ribosomal DNA of isolate Tari 25141 (GenBank Accession No. GU111589) was 831 bp and had 99% sequence identity with a number of Phytophthora cambivora isolates such as GenBank Accession Nos. HM004220 (2), AY787030, and EF486692. Based on the morphological characteristics of sporangia and sexual structures and the molecular analysis of ITS sequences, the pathogen from Taiwan cherry was identified as P. cambivora (Petri) Buis. To our knowledge, this is the first report of P. cambivora on native Taiwan cherry in Taiwan and, so far, no other natural hosts have been reported.

1 aHuang, J H1 aAnn, PJ1 aChiu, Y H1 aTsai, J N uhttp://dx.doi.org/10.1094/PDIS-01-12-0025-PDN02050nas a2200169 4500008004100000022001400041245009600055210006900151260001200220300001400232490000700246520153600253100001401789700001301803700001401816856005001830 2002 eng d a0191-291700aFirst report of bleeding canker caused by Phytophthora cactorum on horse chestnut in Turkey0 aFirst report of bleeding canker caused by Phytophthora cactorum  c06/2002 a697 - 6970 v863 a

Bleeding canker on horse chestnut (Aesculus sp.), caused by Phytophthora cactorum (Lebert and Cohn) Schröeter previously has been reported from the United States and Europe (1). In August 2000, it was found for the first time in a park in Ankara Province, Turkey. Symptoms included sparse yellowish brown foliage with abnormally small leaves, and dark-stained spots or dark brown necrosis of the bark on the trunk and main branches, with or without a reddish black gummy exudate. P. cactorum was isolated from tissues taken from the margins of necrotic bark. Pure cultures were slightly radiate, fluffy but not dense, and had short aerial hyphae when grown on carrot agar, potato dextrose agar, or V8 agar. Sporangia were ovoid, strongly papillate, and averaged 35.6 μm in length and 26.8 μm in width (range: 24 to 55 μm × 19 to 40 μm). The isolates were homothallic with smooth-walled paragynous oogonia ranging from 23.5 to 34.5 μm in diameter. To satisfy Koch's postulates, mycelium of P. cactorum was placed under the bark of six branches of healthy horse chestnut. Noninoculated wounds served as controls. Four months later a reddish black gummy exudate was observed oozing from the inoculated wounds, and the bark tissue was necrotic for 3 to 4 cm around each infection. P. cactorum was successfully reisolated from the necrotic bark tissue. Control wounds remained healthy. To our knowledge, this is the first report of this disease on horse chestnut in Asia Minor.

1 aIntini, M1 aGurer, M1 aOzturk, S uhttp://dx.doi.org/10.1094/PDIS.2002.86.6.697C01628nas a2200181 4500008004100000022001400041245007500055210006900130260001200199300001400211490000700225520104200232100001601274700001601290700001601306700001201322856011201334 2003 eng d a1437-478100aFirst records of soilborne Phytophthora species in Swedish oak forests0 aFirst records of soilborne Phytophthora species in Swedish oak f c06/2003 a175 - 1790 v333 a

Thirty-two oak stands in southern Sweden, 27 with predominantly declining trees and five with a higher proportion of healthy trees were investigated regarding the presence of soilborne Phytophthora species. Phytophthora quercina, an oak-specific fine root pathogen, was isolated from rhizosphere soil samples in 10 of the 27 declining stands. Additionally, P. cactorum and P. cambivora were recovered from one stand each. No Phytophthora species were isolated from the healthy oak stands. The soil conditions at the sites from which Phytophthora spp. were recovered ranged from mesic sediments to moraines, with clayey to silty textures and with soil pH (BaCl2) between 3.5 and 5.0. The results show that P. quercina is geographically widespread in oak stands in southern Sweden and indicate that this pathogen may be one of the factors involved in oak decline in Northern Europe as has already been shown for western, Central and parts of southern Europe.

1 aJönsson, U1 aLundberg, L1 aSonesson, K1 aJung, T uhttps://forestphytophthoras.org/references/first-records-soilborne-phytophthora-species-swedish-oak-forests00628nas a2200169 4500008004100000022001400041245011400055210006900169300000900238490000700247100001400254700001400268700001400282700001400296700001700310856013100327 2009 eng d a0031-949X00aFamily variation in Phytophthora lateralis resistance in Port-Orford-cedar: Greenhouse and raised bed testing0 aFamily variation in Phytophthora lateralis resistance in PortOrf aS1220 v991 aKegley, A1 aKolpak, S1 aReeser, P1 aHansen, E1 aSniezko, R A uhttps://forestphytophthoras.org/references/family-variation-phytophthora-lateralis-resistance-port-orford-cedar-greenhouse-and03670nas a2200217 4500008004100000022001400041245009900055210006900154260001600223300001400239490000800253520293200261100002103193700002103214700001403235700001503249700001603264700001603280700002203296856013403318 2018 eng d a0191-291700aFirst Report of Phytophthora ramorum Lineage EU1 Infecting Douglas Fir and Grand Fir in Oregon0 aFirst Report of Phytophthora ramorum Lineage EU1 Infecting Dougl cJan-02-2018 a455 - 4550 v1023 a

Sudden oak death (SOD) is caused by the introduced oomycete pathogen Phytophthora ramorum S. Werres, A. W. A. M. de Cock & W. A. Man in’t Veld. This fungus-like organism has four clonal lineages: NA1, NA2, EU1, and EU2 (Grünwald et al. 2016; Prospero et al. 2007). Until recently, the NA1 lineage was the only clonal lineage of P. ramorum reported in wildland forests in the western United States. In contrast, EU1, NA1, and NA2 have all been found in U.S. nurseries (Grünwald et al. 2012). In the winter of 2015, a symptomatic Notholithocarpus densiflorus Manos, Cannon & S.H.Oh (tanoak) was identified during a SOD helicopter survey in Curry County, OR. P. ramorum was isolated from symptomatic bark tissue. Subsequently, the isolate was determined to be of the EU1 lineage based on 14 microsatellite loci (Grünwald et al. 2016). Continued monitoring of the area in 2016 and 2017 has identified symptomatic Abies grandis (Douglas ex D. Don) Lindl. (grand fir; n = 3) and Pseudotsuga menziesii (Mirb.) Franco (Douglas fir; n = 2) saplings growing near infected tanoak trees in the mixed conifer forest of Curry County, OR. Symptoms with shoot blight for these species were similar to those described in the literature, including wilting and dieback of new shoots, brown discoloration of needles, and needle loss on young shoots. Isolations were made by plating surface-sterilized tip dieback tissue from A. grandis and P. menziesii on a Phytophthora-selective medium. Based on the presence of chlamydospores, characteristic hyphae, and sporangial morphology, the isolates were identified as P. ramorum. DNA was extracted from hyphae, and a portion of the cellulose binding elicitor lectin (CBEL) gene was amplified and sequenced using the CBEL5U and CBEL6L primers (Gagnon et al. 2014). The sequences of the unknown lineage were aligned to sequences of CBEL for NA1, NA2, EU1, and EU2 using the Staden package in GAP version 4.11.2. The lineage of the isolates from A. grandis and P. menziesii (GenBank accession nos. MF918374 and MF918375, respectively) had 100% identity to the EU1 reference sequences (GenBank nos. EU688952 and EF117945). To satisfy Koch’s postulates, three branches of A. grandis and P. menziessii were inoculated with the original EU1 isolates of P. ramorum from those hosts. Ten days after inoculation, the same pathogen was reisolated from symptomatic stem tissue of both tree species. The EU1 lineage is considered more aggressive than the NA1 lineage and is of opposite mating type to NA1, thus potentially resulting in establishment of sexual populations.

1 aLeBoldus, J., M.1 aSondreli, K., L.1 aSutton, W1 aReeser, P.1 aNavarro, S.1 aKanaskie, A1 aGrünwald, N., J. uhttps://apsjournals.apsnet.org/doi/10.1094/PDIS-05-17-0681-PDNhttps://apsjournals.apsnet.org/doi/full/10.1094/PDIS-05-17-0681-PDN05060nas a2200193 4500008004100000022001400041245010100055210006900156260001600225520443400241100001904675700001704694700001804711700001804729700001704747700001904764700001204783856007104795 2022 eng d a0191-291700aFirst Report of Root Rot Caused by Phytophthora acerina on Metasequoia glyptostroboides in China0 aFirst Report of Root Rot Caused by Phytophthora acerina on Metas cAug-02-20223 a

Metasequoia glyptostroboides Hu & W. C. Cheng (Taxodiaceae), commonly called the Chinese redwood or dawn redwood, is a well-known "living fossil" and rare relict plant species endemic to China, which has been successfully cultivated throughout the world (Ma 2007). In July to September 2020, trees of Chinese redwood which were more than thirty years-old, showed symptoms of decline and death associated with branch dieback, root and collar rot (Fig. 1) in Yangtze River shelter-forests of Jiangling County in Hubei Province, China (112°15′19″E, 30°11′56″N; 40m). Diseased roots and rhizosphere soils were collected in September 2020 and April 2021. Using the baiting method, a homothallic Phytophthora sp. was recovered consistently from diseased roots and soil samples of Chinese redwood. All the isolates of this Phytophthora sp. formed similar colonies on V8 agar and corn meal agar (Fig. 2), and then three representative isolates (L4-5-4, L4-5-5 and L4-5-6) were randomly selected for morphological and molecular identification. In distilled water, semipapillate persistent sporangia were borne in simple sympodial branched sporangiophores. Sporangia were predominantly ovoid (Fig. 3a, d and f), but other shapes were observed including subglobose (Fig. 3b), limoniform (Fig. 3c) or distorted shapes (Fig. 3e), averaging 44.1 ± 7.7 µm (n=102) in length and 32.8 ± 5.2 µm (n=102) in width, with narrow exit pores of 8.0 ± 1.4 µm (n=93) and a length/breadth ratio of 1.3 ± 0.10 (n=102). Chlamydospores were not observed. Oogonia were globose or subglobose, 20.51 to 40.15 µm (av. 33.1 ± 3.9 µm) (n=119) in diameter, with smooth walls and paragynous antheridium (Fig. 3g-i). Oospores were globose or subglobose in elongated oogonia with medium wall thickness of 1.9 ± 0.5 µm (n=36), aplerotic or plerotic and 16.9 to 32.6 µm in diameter (av. 26.6 ± 3.8 µm) (n=40). According to the above morphological characteristics, this Phytophthora sp. was placed in Waterhouse's (1963) group III. The sequences of the internal transcribed spacers (ITS) region of nuclear ribosomal DNA of each isolate (GenBank Accession No. OK087320, OK087321 and OK087322) was 760 bp and had identity of 99.84% with three P. acerina isolates (JX951285, JX951291 and JX951296), while the 800 bp β-tubulin (BTUB) sequences (OK140540, OK140541 and OK140542) showed 99.97% homology to the sequence of P. acerina (KC201283) (Ginetti, Moricca and Squires 2014) (Table 1). The ML phylogenetic trees were established by comparing ITS and BTUB sequences of three Phytophthora strains (L4-5-4, L4-5-5 and L4-5-6) with reference sequences of isolates of Phytophthora in ITS and BTUB in GenBank (Fig. 4-5). Based on the morphological and molecular characteristics, the strains were identified as namely P. acerina. In addition, pathogenicity assays were performed with one of the three strains (L4-5-4) on M. glyptostroboides using both one year old and three years old seedlings. Inoculum was prepared by subculturing agar plugs from edges of CMA cultures into V8 medium plates, incubating at 20 ℃ in darkness for 10 days. Six seedlings planted in pots filled with sterilized soil were inoculated by mycelium plug at root collar and stem wounded by a 8 mm diameter puncher. Six control seedlings were inoculated in the same manner as above, and sterile agar plugs were used. After 35 days, inoculated seedlings all had necrotic lesions at the inoculation sites, and some seedlings had the symptoms of foliage blight and dieback, whereas control seedlings remained healthy (Fig. 6). The number of fibrous roots after inoculation was significantly less than the control, and the roots of inoculated seedlings blackened or even rotted, while there were no obvious symptoms in the control (Fig. 7). Phytophthora isolates recovered from the symptomatic tissues of artificially inoculated plants were identical to isolate L4-5-4 in morphological characters and ITS sequencing. This is the first report of P. acerina causing root rot on the Chinese redwood in China. As only the seedlings were inoculated, further research is needed to address the epidemiology and pathogenicity of P. acerina to adult trees of Chinese red wood. References: Ginetti, B. et al. 2014. Plant Pathology, 63(4): 858-876. Ma, J. S. 2007. Bulletin of the Peabody Museum of Natural History, 48(2): 235-253. Waterhouse, G. M. 1963. Mycological Papers 92:1-22

1 aLiu, Duanchong1 aZhao, Wenxia1 aHuai, Wen-Xia1 aXia, Jianping1 aCai, Sanshan1 abin Zhang, Ru-1 aLi, Bin uhttps://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS-12-21-2722-PDN03930nas a2200205 4500008004100000022001400041245009100055210006900146260001600215300001400231490000700245520331000252100001603562700001303578700001603591700001603607700001703623700001803640856006603658 2009 eng d a0191-291700aFirst Report of Phytophthora tentaculata Causing Root and Stem Rot of Oregano in Italy0 aFirst Report of Phytophthora tentaculata Causing Root and Stem R cJan-08-2009 a843 - 8430 v933 a

Oregano (Origanum vulgare L.; Lamiaceae) is cultivated for culinary and medicinal purposes and as an ornamental. In October of 2007, 1- to 2-year-old potted plants of oregano showed symptoms of decline associated with root and basal stem rot in a nursery in Liguria (northern Italy) that produces 1 million to 1.5 million potted aromatic plants per year. Aboveground symptoms included leaf russeting and chlorosis, wilt, defoliation and dieback of twigs, browning of the basal stem, and subsequent collapse of the entire plant. Approximately 80% of the plants died within 30 days after the appearance of the first symptoms on the canopy. Approximately 20% of a stock of 30,000 oregano plants was affected. Stocks of other aromatic species, such as mint, lavender, rosemary, and sage, appeared healthy. A Phytophthora species was consistently isolated from symptomatic stems and roots of oregano plants on BNPRAH selective medium (2). Ten pure cultures were obtained by single-hypha transfers, and the species was identified as Phytophthora tentaculata Kröber & Marwitz by morphological criteria and sequencing of the internal transcribed spacer (ITS) region of rDNA using the ITS 4 and ITS 6 universal primers for DNA amplification. Isolates from oregano formed stoloniferous colonies with arachnoid mycelium on potato dextrose agar and had a growth rate of 2 to 3 mm per day at 24°C with optimum, minimum, and maximum temperatures of 24, 8, and 34°C, respectively. Sporangia formed in soil extract solution and were papillate and spherical or ovoid to obpyriform with a length/breadth ratio of 1.3:1. Few sporangia were caducous and all had a short pedicel (<5 μm). Hyphal swellings and chlamydospores were produced in sterile distilled water and corn meal agar, respectively. All isolates were homothallic and produced globose terminal oogonia (mean diameter of 34 μm) with one or occasionally two paragynous, monoclinous, or diclinous antheridia. Amphigynous antheridia were also observed. The sequence of the ITS region of the rDNA (GenBank No. FJ872545) of an isolate from oregano (IMI 395782) showed 99% similarity with sequences of two reference isolates of P. tentaculata (Accession Nos. AF266775 and AY881001). To test for pathogenicity, the exposed root crowns of 10 6-month-old potted plants of oregano were drench inoculated with 10 ml of a suspension of 2 × 104 zoospores/ml of isolate IMI 395782. Sterile water was pipetted onto the roots of 10 control plants. All plants were maintained in 100% humidity at 22 to 24°C in a greenhouse under natural light and watered once a week. Within 3 weeks after inoculation, all inoculated plants developed symptoms identical to those observed in the nursery and died within 30 to 40 days after the appearance of the first symptoms. Control plants remained healthy. P. tentaculata was reisolated solely from symptomatic plants. P. tentaculata has been reported previously on several herbaceous ornamental plants (1,3). However, to our knowledge, this is the first report of this species on O. vulgare. Root and basal stem rot caused by P. tentaculata is the most serious soilborne disease of oregano reported in Italy so far.

1 aMartini, P.1 aPane, A.1 aRaudino, F.1 aChimento, A1 aScibetta, S.1 aCacciola, S O uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-93-8-0843B03516nas a2200157 4500008004100000022001400041245009600055210006900151260001600220300001600236490000700252520300300259100001303262700001703275856006603292 2008 eng d a0191-291700aFirst Report of Stalk Rot Caused by Phytophthora tentaculata on Aucklandia lappa in China0 aFirst Report of Stalk Rot Caused by Phytophthora tentaculata on  cJan-09-2008 a1365 - 13650 v923 a

Phytophthora tentaculata causes root and stalk rot of Chrysanthemum spp., Delphinium ajacis, and Verbena spp. in nurseries in the Netherlands and Germany (2). In later years, P. tentaculata was isolated from Verbena hybrids (3) and lavender cotton (Santolina chamaecyparissus) in Spain (1). In August 2007, stalk rot symptoms were observed on Aucklandia lappa (Asteraceae), an economically important Chinese medicinal plant, in some fields in Yunnan Province of China. Small groups of infected plants were randomly distributed throughout the fields. Plants showing stalk rot and wilting died rapidly. Diseased tissues were cut into 10-mm pieces and plated onto Phytophthora selective medium, P5ARP (2), to obtain the pure cultures. Seven isolates were obtained, and five isolates were grown on solidified LBA (60 g of lima bean powder and 15 g of agar per 10,000 ml of distilled water) and 10% V8 juice liquid medium for examination of morphological and physiological characteristics (4). The colony surface texture was uniform and formed sparse, loosely branched mycelium on LBA medium. Radial growth rate was 2 to 3 mm per day at 24°C on LBA. In water, relatively small swellings were formed at hyphal branches. Sporangia were spherical or ovoid to obpyriform and some were distorted and papillate with a narrow exit pore. Approximately 10% of the sporangia were caducous with a short pedicel. Sporangial dimensions were 28 to 47 (35) × 21 to 36 (29) μm, length/breadth ratio 1.2. Chlamydospores formed on LBA after 1 week and were terminal, spherical, thin walled, and 21 to 31 (27) μm in diameter. The isolates were homothallic. Oogonia abundantly formed on LBA and were 25 to 36 (31) μm in diameter. One or two paragynous antheridia (15 × 10 μm) were attached to the oogonia. Oospores were spherical, hyaline, aplerotic, and 20 to 32 (25) μm in diameter. The minimum temperature for mycelium growth was 8°C and maximum temperature was 34°C. The internal transcribed spacer (ITS) region was amplified and sequenced and agreed 100% with sequences of four P. tentaculata isolates deposited in GenBank (Accession Nos. AJ854302, AY881001, DQ335634, and AF266775). Pathogenicity was assessed by flooding three potted A. lappa plants with a 104 ml–1 zoospore suspension and incubating at 20 to 22°C. As controls, two potted A. lappa plants were flooded with deionized water. All three inoculated A. lappa plants exhibited stalk rot after 15 days, from which the pathogen was reisolated using selective medium, P5ARP. Controls remained healthy 15 days after inoculation, To our knowledge, this is the first report of P. tetaculata H. Kroeber & R. Marwitz infection of A. lappa in China. We speculate that the pathogen might have been introduced from other countries on seeds.

1 aMeng, J.1 aWang, Y., C. uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-92-9-1365B04475nas a2200169 4500008004100000022001400041245006900055210006800124260001600192300001400208490000700222520383400229100001604063700001304079700002504092856018804117 2004 eng d a0032-086200aFirst report of Phytophthora tentaculata on Verbena sp. in Spain0 aFirst report of Phytophthora tentaculata on Verbena sp in Spain cJan-12-2004 a806 - 8060 v533 a

The oomycete Phytophthora tentaculata causes root and stalk rot of Chrysanthemum spp., Delphinium ajacis and Verbena spp. in nurseries in the Netherlands and Germany (Kröber & Marwitz, 1993). In June 2001, P. tentaculata was isolated from a young potted Verbena hybrid, showing a collar and stalk rot, in a nursery in Majorca (Balearic Islands, Spain). It was initially recovered by plating ∼10 mm pieces of necrotic tissue from the leading lesion on to a phytophthora selective medium, P5ARP (Erwin & Ribeiro, 1996). A pure culture (isolate CBS 115458) was obtained by transferring aseptically a hyphal tip onto corn meal agar (CMA) and was first identified from morphological characters.

The colony surface texture was uniform and formed sparse, loosely branched mycelium on carrot piece agar (CPA: 50 g carrot pieces and 20 g agar per 1000 mL distilled water) and CMA. The radial growth rate was 2–3 mm day−1 at 20°C on CMA. Sporangia did not appear on either agar media but formed readily in soil extract (50 g soil from a holm oak forest suspended in 1 L ionized water for 24 h at 20°C and then filtered and autoclaved). The sporangia were ovoid to globose, 27–52 (36·9) × 17–31 (24·6) µm, length:breadth ratio 1·4, papillate with a narrow exit pore, and some were caducous with a short pedicel (< 5 µm). Hyphal swellings were present in water. Chlamydospores were only seen on CMA after 2 weeks. Oogonia, readily produced on CPA in pure culture, were globose, mostly terminal or a few lateral, and ranged from 17 to 41 (34·0) µm in diameter. Single paragynous, monoclinous or diclinous, usually long-stalked antheridia were club-shaped or spherical, 9–16 (12·7) µm in diameter and many had appendages. Occasionally two paragynous antheridia per oogonium, as well as some amphigynous antheridia, were observed. Oospores were aplerotic 16–33 (28·4) µm in diameter and thin-walled.

To further confirm its identity, isozyme analysis based on malate dehydrogenase (EC 1.1.1.37) and malic enzymes (EC 1.1.1.40) was performed. Isozyme profiles fitted exactly those of three P. tentaculata strains: two strains ex-Chrysanthemum (including CBS 552.96 paratype) and one strain ex-Verbena; and differing from those of all other papillate species (Oudemans & Coffey, 1991a,b). Pathogenicity was assessed by flooding three potted Verbena plants with a 104 mL−1 zoospore suspension for 48 h at 20–22°C. As controls, two potted Verbena plants were flooded with ionized water. Controls remained healthy 15 days after inoculation. All three inoculated Verbena plants exhibited collar rot after 15 days, from which the pathogen was reisolated using PARP medium, thus confirming Koch's postulates. This is the first report of P. tentaculata in Spain.

1 aMoralejo, E1 aPuig, M.1 aVeld, W., A. Man in' uhttp://www.blackwell-synergy.com/toc/ppa/53/6http://doi.wiley.com/10.1111/j.1365-3059.2004.01089.xhttp://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3059.2004.01089.x00502nas a2200157 4500008004100000245008700041210006900128300001100197490000700208100001000215700001300225700001300238700001300251700001400264856006600278 2008 eng d00aFirst report of chestnut ink disease by Phytophthora katsurae on chestnut in Korea0 aFirst report of chestnut ink disease by Phytophthora katsurae on ap. 3120 v921 aOh, E1 aLee, S H1 aKim, K H1 aLee, J K1 aShin, K C uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-92-2-0312A01183nas a2200205 4500008004100000245011100041210006900152300001000221490000700231520048600238653001000724653002000734653001800754653001300772653000900785100002000794700001400814700001400828856013500842 2006 eng d00aFirst record on Phytophthora spp. associated with the decline of European beech stand in south-west Poland0 aFirst record on Phytophthora spp associated with the decline of  a37-460 v423 a

Phytophthora citricola was detected in Siewierz Forest District in soil samples and diseased bark taken from declined 88-111-year-old European beech trees growing in three compartments of Trzebyczka Forest. Phytophthora cambivora was isolated only from diseased fine roots, bleeding cankers near trunk base and aerial canker spots. Both species colonised leaves and young stem parts as well as five-year-old beech branches. Necrosis spread about 1 mm/24 h.

10aBeech10ableeding canker10apathogenicity10aroot rot10asoil1 aOrlikowski, L B1 aOszako, T1 aSzkuta, G uhttps://forestphytophthoras.org/references/first-record-phytophthora-spp-associated-decline-european-beech-stand-south-west-poland04968nas a2200217 4500008004100000022001400041245013400055210006900189260001600258520420400274100002304478700002804501700001704529700002304546700002004569700001904589700002104608700002604629700002404655856007104679 2022 eng d a0191-291700aFirst report of the NA2 clonal lineage of the sudden oak death pathogen, Phytophthora ramorum, infecting tanoak in Oregon forests0 aFirst report of the NA2 clonal lineage of the sudden oak death p cFeb-02-20223 a

Phytophthora ramorum Werres, de Cock & Man in’t Veld, causal agent of sudden oak death (SOD) and ramorum leaf blight, is comprised of four clonal lineages in its invasive ranges of North America and Europe (Grünwald et al. 2012, Van Poucke et al. 2012). Of these, three – the NA1, NA2, and EU1 lineages – are found in U.S. nurseries, but only two, the NA1 and EU1 lineages, have been found infecting trees in North American forests (Grünwald et al. 2012, 2016). In the spring of 2021, tanoak (Notholithocarpus densiflorus Manos, Cannon & Oh) displaying symptoms consistent with SOD were detected north of Port Orford (Curry County, Oregon). Symptoms were canopy dieback and blackened petiole and stem lesions on tanoak sprouts. The pathogen isolated on PAR (CMA plus 200 ml/L ampicillin, 10 mg/L rifamycin, 66.7 mg/L PCNB) selective media was determined to be P. ramorum based on characteristic morphology of hyphae, sporangia, and chlamydospores (Werres et al. 2001). Positive identification as P. ramorum was obtained with a lineage-specific LAMP assay targeting an NA2 orphan gene, indicating the presence of the NA2 lineage. NA2 was confirmed by sequencing a portion of the cellulose binding elicitor lectin (CBEL) gene using CBEL5U and CBEL6L primers (Gagnon et al. 2014). Sequences (GenBank accessions MZ733981 and MZ733982) were aligned against reference sequences for all lineages (Gagnon et al. 2014) confirming the presence of NA2. Lineage determination as NA2 was further confirmed at eleven SSR loci (ILVOPrMS145, PrMS39, PrMS9C3, ILVOPrMS79, KI18, KI64, PrMS45, PrMS6, ILVOPrMS131, KI82ab, and PrMS43) using the methods of Kamvar et al. (2015). We completed Koch’s postulates using potted tanoaks, wound-inoculated at the midpoint of 1-year old stems with either hyphal plugs or non-colonized agar (n=4 per treatment). Tanoaks were maintained in a growth chamber (20°C-day / 18°C-night temperatures) with regular watering and an 18-photoperiod using F32T8 fluorescent bulbs (Phillips, Eindhoven, The Netherlands). After 7 days, brown to black lesions 1.2 to 2.9 cm in length were observed on the inoculated stems, from which P. ramorum was subsequently re-isolated; no symptoms were observed on the controls, and no pathogens were recovered when plating the wound sites in PAR. This is the first detection of the NA2 lineage causing disease in forests worldwide. The outbreak was found on private and public lands in forests typical to the SOD outbreak in Oregon (mixed conifer and tanoak), and was 33 km north of the closest known P. ramorum infestation. Follow-up ground surveys on adjacent lands have identified over 100 P. ramorum-positive tanoak trees, from which additional NA2 isolates have been recovered from bole cankers. NA2 is thought to be more aggressive than the NA1 lineage (Elliott et al. 2011), which has been present in Curry County since the mid-1990s (Goheen et al. 2017). Eradication of the NA2 lineage is being pursued to slow its further spread and prevent overlap with existing NA1 and EU1 populations. The repeated introductions of novel lineages into the western United States native plant communities highlights the vulnerability of this region to Phytophthora establishment, justifying continued monitoring for P. ramorum in nurseries and forests. References • Elliott, M, et al. 2011. For. Path. 41:7. https://doi.org/10.1111/j.1439-0329.2009.00627.x • Gagnon, M.-C., et al. 2014. Can. J. Plant Pathol. 36:367. https://doi.org/10.1080/07060661.2014.924999 • Goheen, E.M., et al. 2017. For. Phytophthoras 7:45. https://doi: 10.5399/osu/fp.7.1.4030 • Grünwald, N. J., et al. 2012. Trends Microbiol. 20:131. https://doi.org/10.1016/j.tim.2011.12.006 • Grünwald, N. J., et al. 2016. Plant Dis. 100:1024. https://doi.org/10.1094/PDIS-10-15-1169-PDN • Kamvar, Z.N. et al. 2015. Phytopath. 105:982. https://doi.org/10.1094/PHYTO-12-14-0350-FI • Van Poucke, K., et al. 2012. Fungal Biol. 116:1178. https://doi.org/10.1016/j.funbio.2012.09.003 • Werres, S., et al. 2001. Mycol. Res. 105: 1155. https://doi.org/10.1016/S0953-7562(08)61986-3

1 aPeterson, Ebba, K.1 aSondreli, Kelsey, Liann1 aReeser, Paul1 aNavarro, Sarah, M.1 aNichols, Casara1 aWiese, Randall1 aFieland, Valerie1 aGrünwald, Niklaus, J1 aLeBoldus, Jared, M. uhttps://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS-10-21-2152-PDN04226nas a2200181 4500008004100000022001400041245007600055210007000131260001600201300001400217490000800231520364300239100002203882700002303904700002103927700003003948856006603978 2017 eng d a0191-291700aFirst Report of Phytophthora × multiformis on Alnus glutinosa in Spain0 aFirst Report of Phytophthora × multiformis on Alnus glutinosa in cJan-01-2017 a261 - 2610 v1013 a

Alder species are threatened by a lethal disease caused by the oomycete Phytophthora alni, one of the most important emergent pathogens of natural ecosystems in Europe during the last 20 years (Aguayo et al. 2014). Phytophthora alder decline has caused substantial economic losses and ecological damage from riparian alder populations. Initially, three different subspecies had been described, P. alni subsp. alni, P. alni subsp. uniformis, and P. alni subsp. multiformis. Recently, they have been raised to species status and renamed P. × alni, P. uniformis, and P. × multiformis, respectively (Husson et al. 2015). P. × alni was reported to be the most aggressive and pathogenic to alders. The other two species appear to be less aggressive, but are also considered pathogenic (Brasier and Kirk 2001). In Spain, P. × alni and P. uniformis has also been detected (Pintos Varela et al. 2012). In April 2014, crown dieback and mortality of Alnus glutinosa were noted across the riparian area along the Muiños River in Galicia (northwest Spain). Affected trees, showing abnormally small, yellow, and sparse leaves and necrotic lesions in the inner bark, were surveyed. Samples of bark including the cambium from active lesions, roots, and soil were collected. Phytophthora spp. were baited from saturated rhizosphere soil using carnation petals. Roots and tissue from fresh active inner bark lesions were plated onto selective medium V8-PARPH agar and incubated for 7 days at 22°C in the dark. A Phytophthora sp. isolated from root and bark was transferred to carrot agar (CA) and incubated in the dark. Colonies on CA were irregular with upper temperature limits for growth at 30°C. The isolates were homothallic, with smooth to extremely ornamented oogonia. Oogonial diameters ranging from 42 to 59 µm and one or two celled amphigynous antheridia were observed. In soil extract, noncaducous, nonpapillate, ellipsoid to ovoid sporangia were produced. Amplification of DNA was accomplished by using SCAR-PCR primers (Ioos et al. 2005). DNA samples of Phyophthora isolates have amplified using primers pairs PAM-F/R and PA-F/R. No amplicon was obtained using PAU-F/R primers. ITS (DC6-ITS6/ITS4) and nadh1 (NADHF1/NADHR1) mitochondrial gene regions were also amplified and deposited in GenBank (accession nos. KX090045 and KX090044 isolate CECT 20954). Comparison of the sequences showed 100% homology with P. × multiformis (KJ755099 and FJ696567). Pathogenicity of P. × multiformis isolate CECT 20954 was performed by inoculating 10 3-year-old A. glutinosa plants growing in pots. One shallow cut was made at the root collar level. A colonized 5-mm mycelial agar plug from a 7-day-old culture was inserted in every wound and sealed with Parafilm. Five control plants were inoculated with a sterile agar plug. Plants were maintained in a controlled chamber at 24°C and 80% humidity for 2 months. After a 5-week incubation period, inoculated plants showed dieback symptoms and necrosis of the inner bark tissue. Lesion lengths ranged from 2 to 10 cm. Control plants remained symptomless. P. × multiformis was recovered from all inoculated plants, but not from controls. To our knowledge, this is the first report of P. × multiformis in Spain. With this report, the detection of the P. alni species complex in Spain has been completed.

1 aPintos-Varela, C.1 aRial-Martínez, C.1 aAguín-Casal, O.1 aMansilla-Vázquez, J., P. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-08-16-1092-PDN00932nas a2200121 4500008004100000245011700041210006900158300001200227490001600239520040700255100001200662856013600674 1999 eng d00aFactors involved in the development of nutfall [Cocos nucifera nuts] due to Phytophthora katsurae in Ivory Coast0 aFactors involved in the development of nutfall Cocos nucifera nu a150-1530 v16/17 No. 33 aNut rot on coconut can be spread simply by contact or by spreading agents which maintain isolated infections within a bunch on a given tree and at plot level. The disease generally spreads horizontally from one bunch to another and vertically, particularly vertically downwards, from one nut to another in a given bunch. The positive effect of water and insects in disease spread has been demonstrated.1 aPohe, J uhttps://forestphytophthoras.org/references/factors-involved-development-nutfall-cocos-nucifera-nuts-due-phytophthora-katsurae-ivory04718nas a2200169 4500008004100000022001400041245010900055210006900164260001600233300002000249520414900269100001604418700001404434700001704448700001604465856006704481 2017 eng d a0191-291700aFirst report of alder Phytophthora cosely related to P. uniformis on Alnus glutinosa seedling in Finland0 aFirst report of alder Phytophthora cosely related to P uniformis cApr-12-2017 aPDIS-03-17-03223 a

The allotriploid Phytophthora × alni (Brasier & S.A. Kirk) Husson, Ioos & Marcais and its progenitors, the diploid P. uniformis (Brasier & S.A. Kirk) Husson, Ioos & Aguayo and the allotetraploid P. × multiformis (Brasier & S.A. Kirk) Husson, Ioos & Frey are the causal agents of alder decline in Europe. In June 2015, a dark, ∼40 mm stem lesion was found on one out of 100 inspected Alnus glutinosa (L.) Gaertn seedlings in Mäntyharju, Finland. Surface wood pieces from the lesion edges were plated onto malt agar. Cultures on carrot piece agar (CPA) showed an appressed colony with woolly aerial mycelium. Oogonia (Ø mean 44.8 µm, n = 50) and oospores (Ø mean 40.0 µm, n = 50) developed after 7 days at 20°C in the dark. They were commonly smooth walled, and 49 out of 50 of the amphigynous antheridia were single celled. Sporangia (21.7 × 18.1 µm, n = 50) were produced on pea broth, with 2-day flooding with soil extract, and they were commonly unpapillate and obpyriform-ellipsoidal. DNA was extracted, and the internal transcribed spacer (ITS) rDNA was amplified (ITS6 and ITS4; Cooke et al. 2000). The PCR products were then cloned because of double peaks in the sequence. Among 33 clones, four alleles with five polymorphic bases were obtained (A1, 55%; A2, 6%; A3, 15%; and A4, 24%; these were deposited in GenBank as accession nos. MF356294, MF356295, MF356296, and MF356297, respectively). The closest match to the ITS allele sequences in GenBank was the very closely related species P. cambivora AF087479 (differences, 7 to 9 bases). All other sequenced regions showed single alleles. The mitochondrial cox spacer (MF356298; amplified by FMPhy8 and FMPhy10, Martin et al. 2004) matched 100% with P. cambivora P1431 (GU221955) and P. alni P16202 (GU221933) in GenBank. A partial beta tubulin gene (MF356299; amplified by 901F and 1401R, Bilodeau et al. 2007) matched 100% with P. uniformis ALN58 (KU899249). ASF-like, GPA1, RAS-Ypt, and TRP1 genes were amplified with primers by Ioos et al. (2006). GPA1 (MF356301) matched 100% with P. uniformis PAU84 (DQ092849), and RAS-Ypt (MF356302) had exact matches with four P. uniformis isolates in GenBank (e.g., PANM53 and EU371549). The TRP1 gene (MF356303) differed by 1 base from P. uniformis alleles PAU60 (DQ202480) and PAU89 (DQ202481). The ASF-like gene (MF356300) matched 100% with PAU84 (DQ092815). Nine 1-year-old seedlings of A. glutinosa and of Betula pendula Roth were inoculated with plugs from 10-day-old mycelial culture on CPA after making a bark incision. Nine control seedlings of each species received a sterile CPA plug. Inoculations were wrapped in damp cotton wool, and the plants were kept outdoors at 10 to 22°C. After 15 days, eight out of nine (89%) A. glutinosa seedlings had developed lesions (mean length 22 mm), as well as six out of nine (67%) B. pendula seedlings (mean length 4 mm). No lesions were observed in control seedlings. The pathogen was reisolated from two symptomatic seedlings of both hosts. This is the first report of an alder Phytophthora in Finland. The sequence data suggested the isolate to be closely related but dissimilar to P. uniformis. The morphology corresponded to that previously reported for P. uniformis (Brasier et al. 2004), except for the antheridia, which were almost all single celled. Multiple ITS alleles could also refer to the initially reported P. uniformis karyotype 2n+2 (Brasier et al. 2004). These findings add to our knowledge on the variation among the alder Phytophthora group. Furthermore, they demonstrate the risk that the pathogen could be transported in new hosts.

1 aPoimala, A.1 aWerres, S1 aPennanen, T.1 aHantula, J. uhttps://apsjournals.apsnet.org/doi/10.1094/PDIS-03-17-0322-PDN05784nas a2200205 4500008004100000022001400041245007800055210006900133260001600202300000900218490000800227520517100235100001805406700001705424700001605441700001805457700001405475700002205489856006705511 2020 eng d a0191-291700aFirst Report of the NA2 Clonal Lineage of Phytophthora ramorum in Indiana0 aFirst Report of the NA2 Clonal Lineage of Phytophthora ramorum i cApr-20-2020 a18750 v1043 a

The oomycete pathogen Phytophthora ramorum is the causal agent of ramorum leaf blight and sudden oak death (Rizzo et al. 2002). P. ramorum is known to cause leaf blight and stem dieback on nursery hosts including Rhododendron. The disease typically results in dark, brownish lesions on leaves or stems, which can cause wilting and death of the plant (Grünwald et al. 2008; Werres et al. 2001). Since the emergence of the disease, a federal quarantine was established to prevent the spread of the pathogen, and nurseries that export P. ramorum hosts are subject to a federally mandated certification program for interstate export (Grünwald et al. 2012). This disease has had a significant impact on the U.S. nursery industry via quarantine regulations imposed on nurseries infested with the pathogen. The pathogen has been introduced at least three times into the Western United States as clonal lineages NA1, NA2, and EU1 (Grünwald et al. 2009, 2019; Ivors et al. 2006). In the spring and summer of 2019, USDA-APHIS reported that a shipment of potentially P. ramorum-infested plants was delivered to several Eastern and Midwestern states. Rhododendron leaves from numerous counties in Indiana, showing characteristic necrotic leaf blight symptoms, were sampled by Indiana Department of Natural Resources (IDNR) nursery inspectors between April 18 and June 3, 2019. These samples were initially screened for the presence of Phytophthora at the Purdue Plant and Pest Diagnostic Laboratory using an ELISA test (Agdia). Subsamples from tissue producing a positive ELISA result were forwarded to the Michigan State University Plant & Pest Diagnostics laboratory for P. ramorum-specific PCR testing, which was later confirmed by USDA CPHST. Leaf surfaces of P. ramorum-positive samples were surface disinfested to remove contaminating organisms by washing vigorously in 50 ml of 70% ethanol for 10 s followed by three rinses in sterile water. Washed leaves were blotted dry on sterile paper towels. From each leaf, 5-mm leaf discs were punched out of the leading edge of leaf lesions, and the resulting leaf discs were submerged in selective V8 medium amended with pimaricin, ampicillin, and rifampicin in Petri dishes. Petri dishes were incubated at 20°C until growth was present. A plug of growth from the leading edge of the resulting colony was transferred to fresh V8 medium containing a 47-mm 0.4-micron polycarbonate filter (Nucleopore) and incubated for approximately 8 days at 20°C. DNA was extracted by the Center for Genome Research and Biocomputing at Oregon State University using the Omega BioTek Plant DNA DS kit (M1130), and part of the cellulose binding elicitor lectin gene (CBEL) was amplified and sequenced with primers CBEL5U and CBEL6L (Gagnon et al. 2014). Sequences were aligned with the CBEL reference sequences of EU1 (KF679685), EU2 (KF679716), NA1 (EU688908), and NA2 (KF679712) (Gagnon et al. 2014). All 26 of the Indiana isolates were unambiguously classified as belonging to the NA2 clonal lineage (GenBank accessions MN601787 to MN601812). This is the first report of the NA2 clonal lineage outside of British Columbia, Washington, and California, indicating that this pathogen was most likely moved West to East. Prior documented lineages detected obtained from P. ramorum-infected plants in Eastern receiving states have only harbored the NA1 clonal lineage (Goss et al. 2009, 2011). As a result of these detections, the IDNR ordered destruction of more than 6,100 Rhododendron plants at retail outlets in Indiana.

1 aPress, C., M.1 aFieland, V J1 aCreswell, T1 aBonkowski, J.1 aMiles, L.1 aGrünwald, N., J. uhttps://apsjournals.apsnet.org/doi/10.1094/PDIS-12-19-2543-PDN03799nas a2200181 4500008004100000022001400041245009800055210006900153260001600222300000900238490000800247520323000255100002103485700001503506700001603521700001403537856006603551 2016 eng d a0191-291700aFirst Report of Phytophthora pseudosyringae Causing Basal Cankers on Horse Chestnut in Sweden0 aFirst Report of Phytophthora pseudosyringae Causing Basal Canker cJan-05-2016 a10240 v1003 a

Phytophthora pseudosyringae causes stem necrosis, and root and collar rot of several woody tree species (Fagus sylvatica, Alnus glutinosa, Castanea sativa, Nothofagus spp., and Quercus spp.) across Europe (Jung et al. 2003; Pintos Varela et al. 2007; Scanu and Webber 2015) and severe dieback of heathland plants such as bilberry (Vaccinium myrtillus) in the UK (Beales et al. 2010). In June 2014, a symptomatic horse chestnut tree (Aesculus hippocastanum) was detected in Sankt Jörgens Park in Gothenburg, southern Sweden (57°45′1.5″ N; 11°57′8.1″ E; elevation 22 m). The tree displayed 30% crown dieback and several tongue -shaped necrosis at the base of the stem. The outer bark over the bleeding patches was removed and small pieces of infected phloem from the margin of the necrosis were directly plated onto CMA-PARPBH selective medium (17 g/liter corn meal agar (CMA), 0.125 g/liter sodium ampicillin, 0.02 g/liter benomyl, 0.07 g/liter hymexazol, 0.1 g/liter PCNB, 0.01 g/liter primaricin, and 0.01 g/liter rifamycin) and incubated at 20°C. Growing hyphae were later transferred to V8 agar and incubated at 20°C in darkness. After 7 days, the colony reached 5.4 cm in diameter and displayed a stellate growth pattern with faint aerial mycelium. Sporangia were sympodial, semipapillate, mostly ovoid, less commonly limoniform to ellipsoid, with a length/breadth average ratio of 1.44 μm (SE = 0.03). Oogonia were 28.1 μm (SE = 0.46) in diameter, smoothly walled, spherical, and with paraginous antheridia, although some amphiginous antheridia were observed. Morphological features and growth pattern on V8 agar corresponded to those of P. pseudosyringae. DNA was extracted from mycelia and the ITS region was amplified and sequenced using the ITS4 and ITS6f primers (Cooke et al. 2000) and deposited in GenBank (Accession No. KU257470). BLAST search showed 99 to 100% identity with reference sequences of P. pseudosyringae deposited in GenBank. Under-bark inoculation with mycelium plugs was performed on 10 one-year-old excised shoots obtained from three different horse chestnut trees. Inoculated shoots were placed over autoclaved and moistened filter paper inside sterile Petri dishes and incubated at 23°C in darkness. After 14 days, the length of the lesion on inoculated shoots was significantly higher than on control shoots (8.53 mm, SE = 0.74 vs. 0.91 mm, SE = 0.93; P < 0.0001). The pathogen was reisolated from all infected shoots fulfilling Koch postulates. To our knowledge, this is the first report of P. pseudosyringae in Sweden and the first report of P. pseudosyringae causing basal cankers and dieback on horse chestnut worldwide. The number of recent reports of damage caused by P. pseudosyringae raises concerns about the potential impact of this pathogen on horse chestnut trees, widely planted as ornamentals in Sweden, as well as to natural beech and oak forests across the country.

1 aRedondo, M., Á.1 aBoberg, J.1 aStenlid, J.1 aOliva, J. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-09-15-1000-PDN03785nas a2200157 4500008004100000022001400041245009600055210006900151260001600220300001600236490000800252520327000260100001703530700001403547856006603561 2016 eng d a0191-291700aFirst Report of Phytophthora pseudosyringae Causing Stem Canker on Fagus sylvatica in Spain0 aFirst Report of Phytophthora pseudosyringae Causing Stem Canker  cJan-07-2016 a1508 - 15080 v1003 a

Phytophthora pseudosyringae T. Jung & Delatour was described in 2003 as a pathogen associated with root and collar rot of several tree species (Fagus sylvatica, Alnus glutinosa, Quercus spp.) (Jung et al. 2003), and as the causal agent of stem lesions on beech in Europe (Scanu and Webber 2016). In August 2015, a beech (Fagus sylvatica L.) tree displaying 25% crown dieback and a bleeding canker at the base of the stem was observed in a forested area used for recreational purpose in Central Pyrenees (42°36.87′ N, 0°46.09′ E, 1,546 m above sea level). Coarse sections of wood surrounding the bleeding patches were sampled and kept moist and cold for 5 days until processed. Once in the laboratory, small phloem pieces from the margin of the lesion were plated onto corn meal agar-PARPBH medium (Jeffers and Martin 1986) and incubated at 20°C. Growing hyphae were transferred to V8 agar and incubated at 20°C in darkness. Colony growth on V8 medium averaged 3.4 cm/week and had a distinct stellate pattern. Sporangia were sympodial, semipapillate, and ovoid, with a length/breadth average ratio of 1.41 μm (SE = 0.02). Oogonia were 21.9 μm (SE = 0.49) in diameter, smoothly walled, spherical, and with paraginous antheridia, although some amphiginous antheridia were observed. Morphological features and growth appearance on V8 corresponded to those reported for P. pseudosyringae (Jung et al. 2003). DNA was extracted from mycelium, and the ITS region was amplified using the ITS4 and ITS6 primers (Cooke et al. 2000). A BLAST search of the sequenced isolate (submitted to GenBank, Accession No. KU321521) showed 100% identity with P. pseudosyringae ITS sequence (AY230190) from Jung et al. (2003). An under-bark inoculation test with mycelia plugs were performed on 16 excised shoots of 1 cm of diameter obtained from four different F. sylvatica trees. After 4 weeks, inoculated shoots displayed longer necrotic lesions than control inoculations with agar (3.55 cm SE: 2.2 versus 0.59 cm SE: 2.8, P < 0.0001). The P. pseudosyringae inoculated shoots exhibited lesions that were dark red underneath the bark, whereas the control lesions did not. P. pseudosyringae, which was identified morphologically, was reisolated from 40% of the infected shoots. No reisolation of the pathogen occurred from any of the six control shoots. Although previously detected in nursery stock on sweet chestnut (Castanea sativa) (Pintos Varela et al. 2007), our report represents the first report of P. pseudosyringae naturally affecting trees in Spain, and widens the geographical distribution of this pathogen in southwestern Europe. In Spain, F. sylvatica is the third species in terms of standing volume, where it covers 400,000 ha, mainly in the Pyrenees. Our finding proves the capacity of this pathogen to establish in nature, and it raises concern over the potential impact on beech forests in Spain.

1 aRedondo, Á.1 aOliva, J. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-12-15-1497-PDN04285nas a2200157 4500008004100000022001400041245011100055210006900166260001600235300002000251520373900271100001704010700002004027700001404047856006604061 2016 eng d a0191-291700aFirst Report of Phytophthora uniformis and P. plurivora Causing Stem Cankers on Alnus glutinosa in Denmark0 aFirst Report of Phytophthora uniformis and P plurivora Causing S cAug-12-2017 aPDIS-09-16-12873 a

Phytophthora uniformis (Brasier & S.A. Kirk) Husson, Ioos & Aguayo, comb. nov. is an aggressive pathogen associated with root and collar rot of alder trees (Alnus spp.) in Europe (Husson et al. 2015). In summer 2016, symptomatic trees were observed in the banks of a backwater lake area of the river Gurre Å (56°1′46.24″N, 12°27′15.30″E, 29 m above sea level). Several trees displayed chlorosis, reduced leaf size, defoliation, and bleeding cankers on the base of the stem. Inspections upstream near Gurre forest failed in finding other trees with similar crown symptoms, whereas a tree with a bleeding canker was observed downstream (56°3′10.97″N, 12°26′4.40″E, 23 m above sea level). Bark from six trees in the first site and from the tree in the second site was removed from the canker area. As described in Redondo et al. (2015), pieces of 1 cm × 0.5 cm × 1 mm of necrotic cambial tissue from the infection front were plated directly into CMA-PARPBH selective medium. Growing hyphae were transferred onto V8 juice agar medium and incubated at 20°C. Isolates from the first site grew 5 mm/day and formed cottony uniform colonies. After 1 week, spherical smooth-walled oogonia often showing two-celled amphigynous antheridia developed profusely (Ø 39.6 μm; SE = 0.84). Sporangia were ellipsoid and nonpapillate, often with nested proliferation. Colonies from the second site grew 5.5 mm/day, and formed a stellate colony pattern with limited aerial mycelium. Abundant spherical (Ø 29.8 μm; SE = 0.53) oogonia with paragynous antheridia formed after 1 week. Sporangia were commonly ovoid and semipapillate. DNA was extracted from all isolates and the ITS region was amplified using the ITS4 and ITS6f primers. BLAST searches showed 99% similarity with P. uniformis sequence no. AF139367.1 for the six isolates from the first site (GenBank accession nos. KX822022 to KX822027), and 99% similarity with P. plurivora sequence no. FJ665227.1 for the isolate from the second site (KX822028). As morphological characteristics of the first six isolates corresponded to those of the P. alni species complex, primers TRP-PAU-F/-R and RAS-PAM1-F/-R (Ioos et al. 2006) were used to classify them as P. uniformis. ITS patterns from Jung and Burgess (2009) were used to classify the P. plurivora-like isolate as P. plurivora. Pathogenicity of two P. uniformis isolates and the P. plurivora isolate was confirmed by immersing 30 alder seedlings, grown in vermiculite for 3 weeks, in a zoospore suspension of each isolate adjusted to 3 × 104 zoospores ml–1 for 3 h. Seedlings were later kept in dark Eppendorf tubes in sterile water, and rewatered daily. After 10 days, mortality was 76.6 and 86.6% among those inoculated with P. uniformis, and 60% for those inoculated with P. plurivora. Surviving seedlings after 10 days displayed wilting symptoms, while seedlings immersed in water were symptomless. The roots of the dead seedlings were plated onto CMA-PARPBH selective medium. Growing hyphae were observed in all plated roots, and were transferred to V8 juice agar medium. The reisolated Phytophthora colonies were morphologically similar to P. uniformis and P. plurivora, fulfilling Koch’s postulates. Our finding raises concern about the future health of alder trees in Denmark, a country from which P. alni has not yet been reported. However, symptoms of Phytophthora disease have been observed on alder since 1995 (Thinggaard 1996). Further monitoring should investigate the extent of the outbreak.

1 aRedondo, Á.1 aThomsen, I., M.1 aOliva, J. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-09-16-1287-PDN04559nas a2200205 4500008004100000022001400041245016600055210006900221260001600290300000900306490000700315520385800322100001904180700001404199700001904213700001604232700001704248700002204265856006604287 2015 eng d a0191-291700aFirst Report of Phytophthora occultans Causing Root and Collar Rot on Ceanothus, Boxwood, Rhododendron, and Other Hosts in Horticultural Nurseries in Oregon, USA0 aFirst Report of Phytophthora occultans Causing Root and Collar R cJan-09-2015 a12820 v993 a

Dead and dying Ceanothus sanguineus, C. velutinus, and C. integerrimus plants grown in a native plant nursery in Oregon for landscape restoration were reported in 2011. Plants were wilted with stem lesions above necrotic roots. Using selective media (Hansen et al. 2012), twelve similar Phytophthora isolates were obtained. DNA sequences of the cox 1, β tubulin, and the rDNA ITS regions were generated (Hansen et al. 2012). All isolates had identical ITS sequences (GenBank KP742989), and were identical to Phytophthora occultans (Man in’t Veld et al. 2014) (JX978155) and 99% similar to P. himalsilva (HM752784) in a BLAST analysis. They were also identical to P. occultans in cox 1 and β tubulin (KR028484 and KR028483). Isolates were homothallic, with smooth 30-µm-diameter oogonia, and slightly aplerotic oospores. Antheridia were mostly paragynous. Colonies were stellate on carrot agar, growing 6 to 7 mm/d at optimum temperature (25°C). Sporangia were ovoid to irregular and papillate. Morphology and growth were consistent with P. occultans. Collections of unidentified Phytophthora spp. from the OSU Plant Clinic and from other Oregon nurseries (J. Parke et al. 2014) revealed additional isolates with similar morphology and identical DNA sequences. P. occultans was identified from boxwood (Buxus spp.), rhododendron, Gaultheria shallon, Arctostaphylos uva-ursi, and Mahonia nervosa in addition to Ceanothus spp. Two inoculation trials were conducted: (i) Healthy 1-year-old plants of C. sanguineus and C. velutinus were stem wound inoculated with two isolates of P. occultans from Ceanothus, or with sterile agar. There were 3 to 5 replications for each host and the control. The test was repeated with addition of two isolates from boxwood. (ii) Boxwood (B. sempervirens) and rhododendron (R. catawbiense Alba) were stem wound inoculated with two isolates each of P. occultans from Ceanothus and boxwood. There were four replications of each host for each isolate. All plants were incubated at 20 to 22°C. In test 1, all isolates induced stem lesions and wilting on all inoculated plants of both Ceanothus species. Wilting began in 14 days and lesions, measured at 19 days, averaged about 150 mm. There were no symptoms on control plants. In test 2, lesions developed on rhododendron stems, often girdling the stem within 12 days. Most boxwood showed no foliar symptoms or only mild yellowing, although stem lesions averaging 3.5 cm in 7 weeks were present on all plants. P. occultans was reisolated from all hosts in both tests. P. occultans was recently described from Buxus nursery stock in The Netherlands (Man in’t Veld et al. 2014), and isolates with identical DNA sequences were reported from Germany and Romania (Nechwatal et al. 2014). This is the first report from North America. It appears that a single clone of P. occultans recently has been spread widely in the nursery trade. P. occultans is similar to P. himalsilva (Vettraino et al. 2011) and to other members of the poorly defined P. citrophthora clade. Phylogenetic analysis may revise species definitions. Nursery plants grown for wildland restoration are at high risk to carry exotic Phytophthora species into vulnerable landscapes. Forest restoration specialists must demand healthy stock from nurseries.

1 aReeser, P., W.1 aSutton, W1 aHansen, E., M.1 aGoheen, E M1 aFieland, V J1 aGrünwald, N., J. uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-02-15-0156-PDN01081nas a2200145 4500008004100000245007500041210006900116260004300185490000900228520056100237100002300798700002400821700002200845856006800867 2011 eng d00aFirst Report of Phytophthora ramorum infecting grand fir in California0 aFirst Report of Phytophthora ramorum infecting grand fir in Cali bPlant Management Networkc1 April 20110 v20113 a

Phytophthora ramorum was detected on grand fir in 2003 and 2005 in a Christmas tree plantation near Los Gatos, CA, in association with infected California bay laurel. Isolates derived from stem lesions were used to inoculate grand fir seedlings in two tests. Isolations from lesions on inoculated plants were positive for P. ramorum in both tests. This work provides the completion of Koch’s postulates to establish grand fir as a host of P. ramorum. The potential for grand fir to be infected within its native range is unknown.

1 aRiley, Kathleen, L1 aChastagner, Gary, A1 aBlomquist, Cheryl uhttp://www.plantmanagementnetwork.org/sub/php/brief/2011/grand/01890nas a2200145 4500008004100000245009400041210006900135300001200204490000700216520138800223100001901611700003301630700002101663856006001684 1992 eng d00aFactors influencing the enlargement of trunk cankers of Phytophthora cinnamomi in red oak0 aFactors influencing the enlargement of trunk cankers of Phytopht a367-3740 v223 a

Development of cankers on red oak (Quercus rubra L.) caused by Phytophthora cinnamomi Rands was studied with dendrochronological techniques. Factors of variation among lesions were investigated. Lesion parameters proved to vary with the particular tree to which the lesion belonged. A discriminant factorial analysis and principal component analysis showed that this tree susceptibility was made up of two components. The first accounted for root infection and wound healing. The second concerned susceptibility to vertical spread of the pathogen in bark tissues. Relationships between (i) tree susceptibility and (ii) tree age and vigor were studied. From the occurrence of the first lesion at the collar, number and severity of lesions increased with time, following an exponential and logistic curve, respectively. A comparison of ring widths in infected and healthy trees showed that the disease had no detrimental effect on tree growth. However, annual necrosis length was positively correlated with the annual radial tree growth. The observed differences among trees could not be explained by the effects of time and vigor only. Temperature and drought were analyzed to determine their effect on lesion development. No direct effect of drought on this disease could be shown. The low cold hardiness of P. cinnamomi in the trunk was determined.

1 aRobin, Cécile1 aDesprez-Loustau, Marie-Laure1 aDelatour, Claude uhttp://www.nrcresearchpress.com/doi/abs/10.1139/x92-04801839nas a2200157 4500008004100000245010700041210006900148260009100217490002900308520120100337100002101538700001901559700001601578700001801594856006901612 2007 eng d00aFirst report of Phytophthora siskiyouensis causing disease on Italian alder in Foster City, California0 aFirst report of Phytophthora siskiyouensis causing disease on It aSan Diego, CaliforniabAPS Press, American Phytopathological SocietycJuly 28–August0 vPhytopathology 97: S101.3 a

Phytophthora species cause cankers on the stems of many forest and landscape trees. In November of 2006, Italian alder trees, Alnus cordata, were reported to be dying with symptoms of bleeding cankers located at the base of the stem. The trees were located in a business development outside of a library in Foster City, California. Several of the trees had already been removed as hazardous. Successful isolations were made at the leading edge of the canker from the wood cambium interface onto PARP selective medium. A homothallic Phytophthora with primarily paragynous antheridia grew out in the media. The sporangia, produced easily on carrot agar plugs in soil water were ovoid to ellipsoid in shape. Oospores were mostly globose and aplerotic. The intergenic transcribed spacer region of rDNA of the oomycete matched with 100% identity to Phytophthora siskiyouensis, a pathogen associated with tan oak and also found in the soil and water in coastal Oregon. Pathogenicity experiments were conducted on Italian, red and white alder. This Phytophthora may be endemic to California. Foster City shares a marine- influenced climate with coastal Oregon.

1 aRooney-Latham, S1 aBlomquist, C L1 aPastalka, T1 aCostello, L R uhttp://apsjournals.apsnet.org/doi/pdf/10.1094/PHYTO.2007.97.7.S101570nas a2200193 4500008004100000022001400041245013900055210006900194260001600263300001200279490000700291520092500298100002201223700002201245700001601267700001801283700002001301856005501321 2015 eng d a1522-833900aFirst detection in the US: new plant pathogen, Phytophthora tentaculata, in native plant nurseries and restoration sites in California0 aFirst detection in the US new plant pathogen Phytophthora tentac cJan-03-2015 a23 - 270 v163 a

Phytophthora tentaculata Kröber & Marwitz (Pythiaceae) has been detected in several native plant nurseries in 4 California counties and in restoration sites on orange sticky monkey flower (Diplacus aurantiacus (W. Curtis) Jeps. subsp. aurantiacus [Scrophulariaceae]), toyon (Heteromeles arbutifolia (Lindl.) M. Roem. [Rosaceae]), coffeeberry (Frangula californica (Eschsch.) A. Gray [Rhamnaceae]), and sage (Salvia spp. L. [Lamiaceae]). These findings are the first detections of P. tentaculata in the US and the first ever on these host plants. Phytophthora species are a known problem in horticultural nurseries, but little attention has been placed on native plant or restoration nurseries. The potential for plant pathogens to be outplanted along with native plant nursery stock is very high, posing a threat to neighboring forests.

1 aRooney-Latham, S.1 aBlomquist, C., L.1 aSwiecki, T.1 aBernhardt, E.1 aFrankel, S., J. uhttp://npj.uwpress.org/cgi/doi/10.3368/npj.16.1.2303855nas a2200157 4500008004100000022001400041245011300055210006900168260001600237300001400253490000700267520330900274100002203583700002203605856007003627 2014 eng d a0191-291700aFirst Report of Root and Stem Rot Caused by Phytophthora tentaculata on Mimulus aurantiacus in North America0 aFirst Report of Root and Stem Rot Caused by Phytophthora tentacu cJan-07-2014 a996 - 9960 v983 a

Sticky monkey flower plant, Mimulus aurantiacus (Phrymaceae), is a small, perennial shrub that is widely distributed throughout California, especially in coastal and disturbed habitats. It is also found in native plantings in parks and landscapes. In October 2012, nearly all the M. aurantiacus plants grown in a Monterey County, CA nursery for a restoration project were stunted and had dull, yellowish leaves. Roots and stem collars had necrotic, sunken lesions with few feeder roots. Thirty percent of the plants had died. Samples of diseased plants were sent to the CDFA-PPDC Lab and tested positive for Phytophthora sp. using the Agdia ELISA Phytophthora kit (Agdia, Elkhart, IN). A Phytophthora sp. was consistently isolated from the tissue on corn meal agar-PARP (CMA-PARP) (2). Sporangia were spherical to ovoid, papillate to bipapillate and 17 to 42.5 (avg. 27.5) × 12 to 35 (avg. 22.9) μm, with a length/breadth ratio of 1.2:1. Chlamydospores, which were spherical, terminal to intercalary, thin walled and 27.5 to 40 μm, and hyphal swellings formed on CMA-PARP. Spherical oospores, 25 to 36 μm, with primarily paragynous antheridia formed readily on V8 juice agar. rDNA sequences of the internal transcribed spacer (ITS) region of the isolates (GenBank KF667505), amplified using primers ITS1 and ITS4, were 100% identical to Phytophthora tentaculata (CBS 552.96, GenBank AF266775) by a BLAST query (1,3). To assess pathogenicity, exposed root crowns of three 3.78-liter potted M. aurantiacus plants were inoculated with 20 ml of zoospore suspension (2 × 104 ml−1). Plants were maintained in a 23°C growth chamber with a 12-h photoperiod and watered daily. Sterile water was applied to the exposed crowns of three control plants. At 2 weeks, all inoculated plants were wilted with chlorotic foliage. After 3 weeks, the cortical tissue of the crowns and roots was discolored and sloughing and P. tentaculata was recovered on CMA-PARP. P. tentaculata did not grow from the asymptomatic control plants. Inoculations were repeated with similar results. P. tentaculata is a homothallic species in Phytophthora clade 1 that causes crown, root, and stalk rot of nursery plants in Europe and China (1,4). A USDA PERAL analysis lists it as one of the top 5 Phytophthora species of concern to the United States (4). Genera infected with P. tentaculata include Apium, Aucklandia, Chicorium, Chrysanthemum, Delphinium, Gerbera, Lavandula, Santolina, Origanum, and Verbena (4). To our knowledge, this is the first report of P. tentaculata in North America. The source of inoculum of P. tentaculata in California remains unknown. The nursery used seed and cuttings of M. aurantiacus from nearby native areas for propagation, and P. tentaculata was not found in neighboring plant hosts or by baiting soil and water at the nursery. All infected M. aurantiacus material was destroyed. The presence of P. tentaculata in California nurseries could have serious economic impacts on the nursery industry and environmental impacts on susceptible native hosts, if spread into the wildlands.

1 aRooney-Latham, S.1 aBlomquist, C., L. uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-09-13-1002-PDN05721nas a2200169 4500008004100000022001400041245007000055210006900125260001600194300001400210490000700224520518000231100002305411700002205434700001805456856007705474 2006 eng d a0032-086200aFirst report of Phytophthora boehmeriae on black wattle in Brazil0 aFirst report of Phytophthora boehmeriae on black wattle in Brazi cJan-12-2006 a813 - 8130 v553 a

Black wattle (Acacia mearnsii) is an Australian tree species cultivated in several countries. In Brazil, particularly in Rio Grande do Sul State (RS), approximately 140 000 ha are cultivated for tannin extraction (Dos Santos et al., 2005).

The gummosis complex, which has Phytophthora nicotianae as one of the causal agents, is the main disease of black wattle in Brazil and is characterised by lesions at the trunk base with gum exudation (Dos Santos et al., 2005). Different symptoms were observed in plantations at the municipality of Piratini, RS (southern Brazil) and were characterised by dark lesions without gum exudation on trunks of 3- to 4-year-old wattle trees up to 10 m height. Isolates of Phytophthora spp. were obtained from the lesions and deposited in the Brazilian collection of Phytophthora species, under accession numbers CBP 307, 308 and 309. Sporangia of all isolates were ovoid to spherical, papillate and caducous, measuring 35 µm ± 1·42 × 30 µm ± 1·37, with a length/width ratio of 1·16:1, mean depth of papillae of 4·83 µm ± 0·04, and pore exit of 4·69 µm ± 0·04. The isolates were homothallic, forming plerotic oospores with smooth walls and amphigynous antheridia. The ITS sequences obtained for isolates CBP 307 (AY428533), CBP 308 (AY428534), and CBP 309 (AY428535) were identical and most closely matched those of two isolates of P. boehmeriae KACC40173 (AY228076) from Korea and SCRP23 (DQ297406) from China. This and the morphological similarity (Erwin & Ribeiro, 1996) suggest that these isolates are P. boehmeriae. However, seven clear single base pair differences were noted between the Brazilian and other P. boehmeriae isolates. This, combined with isozyme variation (Oudemans & Coffey, 1991) suggests that further studies are needed to confirm the taxonomic status of P. boehmeriae.

Pathogenicity tests were done by inoculating five 1-year-old wattle plants with 7 mm mycelial discs of 5-day old cultures of the three isolates used in this study. The mycelial discs were placed in 7 mm diameter holes made in the bark with a cork borer, at 5 cm above the soil. Plants were maintained at approximately 25°C and were assessed 45 days after inoculation. All three isolates were pathogenic to black wattle and were re-isolated from the lesions.

Phytophthora boehmeriae was reported as one of the causal agents of the gummosis complex on black wattle in South Africa (TPCP, 2004) and is of quarantine importance for the citrus industry in Brazil. This is the first report of the involvement of P. boehmeriae in the aetiology of the gummosis complex of black wattle in Brazil.

1 aSantos, A., F. dos1 aLuz, E., D. M. N.1 aSouza, J., T. uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1365-3059.2006.01462.x/full04070nas a2200241 4500008004100000022001400041245008200055210006900137260001600206300002000222520335700242100001503599700001503614700001503629700002503644700001403669700001503683700001403698700002103712700001503733700001303748856006703761 2018 eng d a0191-291700aFirst Report of Phytophthora ramorum Causing Japanese Larch Dieback in France0 aFirst Report of Phytophthora ramorum Causing Japanese Larch Dieb cAug-08-2018 aPDIS-02-18-02883 a

Phytophthora ramorum Werres, De Cock & Man in’t Veld, an oomycete known in the United States as the causal agent of sudden oak death, has spread across Europe since the early 2000s. It is responsible for damage and death to a wide range of plant species, including mature trees. In 2009 it was identified on Japanese larch (Larix kaempferi) in southwest England (Webber et al. 2010), and since then it has caused severe damage and losses to Larix spp. in the United Kingdom and the Republic of Ireland. There are two lineages of the oomycete, EU1 and EU2, found in Europe (King et al. 2015), EU2 being the more aggressive. The symptoms on larch include necrosis and loss of needles, wilting of shoots, dieback of branches, and death, often with abundant resin bleeding on trunks and branches. As sporulating hosts, Larix spp. may disperse P. ramorum over long distances. In May 2017, wilting, yellowing/reddening needles, and branch mortality were observed on mature Larix kaempferi (about 50 years old) in the forest of Saint-Cadou, Finistère, in the far northwestern part of France (3°59′49.2″ W; 48°22′22.4″ N). Approximately, 27% of the trees were affected in May, and 42% later in September 2017. The presence of P. ramorum was suspected and was first confirmed by testing samples collected from trunks and branches with necrosis and resin bleeds, using the specific conventional polymerase chain reaction (PCR) method developed by Ioos et al. (2006). The oomycete was also isolated in pure culture, using a Phytophthora selective medium (PARB[H]). The features observed, such as a coralloid mycelium, the presence of numerous thin-walled chlamydospores (up to 75 µm large), and deciduous, semipapillate sporangia arranged in clusters, matched those reported for P. ramorum. In June 2017, the presence of P. ramorum was confirmed in another larch stand in Hanvec, Finistère (4°12′45.0″ W; 48°20′10.8″ N), using the same identification techniques. In this stand, the prevalence was not precisely estimated but was deemed much lower than in Saint-Cadou. Based on the analysis of Cox1 partial sequence and the PCR restriction fragment length polymorphism pattern described by Van Poucke et al. (2012) on Cox1, the P. ramorum isolates collected in these two forests could be assigned to the EU1 lineage. This is the first report of P. ramorum affecting Japanese larch in France and in mainland Europe. Until now it had only been detected on shrubs in nurseries, green spaces, and in rare circumstances in the natural environment on understory vegetation (rhododendron) in Normandy and Brittany, but not in the vicinity of the infected larch stands. The presence of this pathogen in the natural environment represents a major threat for larch trees, but also for the other potential forest host trees in this region, such as sweet chestnut, and might have a severe impact on both forest and ornamental tree species. Research is in progress to learn more about this outbreak, the possible origin of the inoculum, the extension of the disease, and its progression.

1 aSchenck, N1 aSaurat, C.1 aGuinet, C.1 aFourrier-Jeandel, C.1 aRoche, L.1 aBouvet, A.1 aHusson, C1 aSaintonge, F.-X.1 aContal, C.1 aIoos, R. uhttps://apsjournals.apsnet.org/doi/10.1094/PDIS-02-18-0288-PDN04806nas a2200157 4500008004100000022001400041245013300055210006900188260001600257300000900273490000800282520425600290100001504546700002004561856006704581 2020 eng d a0191-291700aFirst Report of Phytophthora acerina, P. plurivora, and P. pseudocryptogea Associated with Declining Common Alder Trees in Italy0 aFirst Report of Phytophthora acerina P plurivora and P pseudocry cApr-17-2020 a18740 v1043 a

Since the early 1990s, common alder (Alnus glutinosa) trees showing a variety of symptoms such as a partial or complete canopy dieback, reddening of foliage, and bleeding cankers at the collar and lower stem were observed in several torrential mountain streams in Sardinia (Italy). In order to clarify the etiology of the symptoms observed, three riparian alder stands along three streams in northern Sardinia were surveyed in the spring of 2017. In each stand a 100-m-long transect was established, and 10 symptomatic alder trees per transect were sampled for Phytophthora species. Phytophthora isolations from 30 rhizosphere samples (300 g of soil and roots) collected around the selected alder trees and 30 inner bark samples taken from the margin of active lesions at the collar region of the same trees were performed as described by Linaldeddu et al. (2020). Disease incidence among transects ranged from 81 to 97%. Based on colony growth patterns on carrot agar (CA), morphological features of sporangia and sequence analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of rDNA, the 40 Phytophthora isolates obtained were identified as Phytophthora acerina (seven isolates with ovoid sporangia measuring 48.9 × 33.1 μm), P. plurivora (24 isolates with ovoid sporangia measuring 50.1 × 32.9 μm), and P. pseudocryptogea (nine isolates with ellipsoid sporangia measuring 44.8 × 26.9 μm). For all Phytophthora species, BLAST searches in GenBank showed 100% identity with reference sequences of representative isolates including those of ex-type cultures (JX951285, FJ665225, and KP288376). The ITS sequence of a representative isolate of each species was deposited in GenBank (P. acerina MN589653, P. plurivora MN589655, and P. pseudocryptogea MN589656). The representative isolates were stored at 10°C under water at the Culture Collection of the University of Padova. The pathogenicity of the representative isolate of each Phytophthora species was evaluated by inoculating five 3-year-old common alder seedlings per isolate. For each seedling a plastic beaker was positioned and sealed at the base of the stem, filled with 130 ml of pond water, and inoculated with 10 agar-mycelium plugs (10 mm) cut from the margin of a 5-day-old CA colony. The water of five control plants was inoculated with sterile CA plugs. Plants were kept in a laboratory at 25°C and watered regularly for 4 weeks. At the end of the experiment, all inoculated plants were symptomatic and displayed reddened to browned leaves and dark brown lesions on the inner bark. The three Phytophthora species were successfully reisolated from symptomatic inner bark tissues of the stem of all plants, fulfilling Koch’s postulates. No disease symptoms were detected on control seedlings, and no Phytophthora species were isolated. The pathogenicity test was conducted twice. P. plurivora was the dominant species and the only species obtained from stem cankers and rhizosphere samples in all sites. This species is regarded as native to Europe and known as an aggressive pathogen of A. glutinosa (Aday Kaya et al. 2018; Haque et al. 2014). P. acerina and P. pseudocryptogea were obtained from both bleeding cankers and rhizosphere samples in two sites. All three Phytophthora species are reported for the first time to be associated with declining common alder trees in Italy, and for the first time the pathogenicity of P. acerina and P. pseudocryptogea has been demonstrated on A. glutinosa. The widespread occurrence and virulence of these Phytophthora species represents a serious threat to riparian alder ecosystems in Sardinia.

1 aSeddaiu, S1 aLinaldeddu, B T uhttps://apsjournals.apsnet.org/doi/10.1094/PDIS-01-20-0186-PDN00545nas a2200133 4500008004100000245015400041210006900195300001400264490000700278100001700285700001900302700001800321856007200339 2003 eng d00aFirst report of root and crown rot caused by Phytophthora cinnamomi affecting native stands of Arctostaphylos myrtifolia and A. viscida in California0 aFirst report of root and crown rot caused by Phytophthora cinnam a1395-13950 v871 aSwiecki, T J1 aBernhardt, E A1 aGarbelotto, M uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2003.87.11.1395B00481nas a2200145 4500008004100000245007300041210006900114300001400183490000700197100001800204700001200222700001500234700001400249856007200263 2000 eng d00aFirst report of Phytophthora root and collar rot of alder in Hungary0 aFirst report of Phytophthora root and collar rot of alder in Hun a1251-12510 v841 aSzabó, Ilona1 aNagy, Z1 aBakonyi, J1 aÉrsek, T uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2000.84.11.1251A03265nas 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-90-0682B04657nas 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-PDN00672nas a2200145 4500008004100000245010600041210006900147260012700216653002900343653002200372653002700394100001200421700001300433856008000446 2004 eng d00aFinal supplemental environmental impact statement management of Port-Orford-cedar in southwest Oregon0 aFinal supplemental environmental impact statement management of  aPortland, ORbU.S. Department of Agriculture - Forest Service, U.S. Department of the Interior - Bureau of Land Management10aChamaecyparis lawsoniana10adisease detection10aPhytophthora lateralis1 aUSDA-FS1 aUSDI-BLM uhttp://www.fs.fed.us/r6/rogue-siskiyou/projects/foresthealth/poc-seis.shtml00667nas a2200181 4500008004100000245005700041210005700098260011100155300001200266490003200278100001800310700002400328700001500352700001700367700001900384700001800403856006400421 2010 eng d00aForest treatment strategies for Phytophthora ramorum0 aForest treatment strategies for Phytophthora ramorum aSanta Rosa, CaliforniabU.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station a239-2480 vGen. Tech. Rep. PSW-GTR-2291 aValachovic, Y1 aC. Lee, Marshall, J1 aScanlon, H1 aFrankel, S J1 aKliejunas, J T1 aPalmieri, K M uhttp://www.fs.fed.us/psw/publications/documents/psw_gtr229/02679nas a2200169 4500008004100000022001400041245008100055210006900136260001200205300001600217490000700233520211000240100001902350700001202369700001502381856011302396 2008 eng d a0191-291700aFirst report of Phytophthora cactorum associated with beech decline in Italy0 aFirst report of Phytophthora cactorum associated with beech decl c12/2008 a1708 - 17080 v923 a

During 2006 and 2007, declining mature beech trees (Fagus sylvatica) were recorded in two stands in the Natural Park of Monti Cimini in central Italy. Symptoms included crown thinning and the presence of bleeding lesions on the main roots and lower stem. Incidence of decline was approximately 5%. Samples of necrotic bark tissue were collected, cut into 5 mm long segments, plated on PARPNH, and incubated at 20°C (1). Phytophthora isolates were obtained from necrotic tissues of 25% of the sampled declining trees. Colonies were rosaceous on potato dextrose agar (PDA) and homothallic. Papillate, ovoid-to-obpyriform, caducous sporangia (mean 38 × 26.2 μm) were produced in soil extract. Oospores were plerotic (mean diameter of 22 to 32 μm) and antheridia paragynous. Optimum growth temperature was 23 to 25°C, minimum 6 to 8°C and maximum 30 to 33°C. A portion of the internal transcribed spacer sequence has been deposited in the NCBI database (GenBank Accession No. FJ183724). A BLAST search of the NCBI database revealed Phytophthora cactorum, Accession No. EU194384, as the closest match with 100% sequence similarity. Pathogenicity of two isolates, PFE3 and IFB-CAC 38, collected from distressed beech trees was tested using a soil infestation test (10 beech seedlings per isolate and control) and an under the bark inoculation method (10 twigs per isolate and controls, wounded and noninoculated taken from a declining beech tree) (2). After 2 weeks at 20°C, twigs and seedlings inoculated with each isolate developed extensive necrotic lesions around the inoculation sites and the collar, respectively, and P. cactorum could be reisolated from all lesions. Controls showed no symptoms. P. cactorum is widespread in declining beech forests in central Europe (1). In Italy, P. cactorum occurs in soils of chestnut and oak forests and was isolated from collar and root lesions of declining walnut trees (3). To our knowledge, this is the first report of P. cactorum being associated with declining beech trees in Italy.

1 aVettraino, A M1 aJung, T1 aVannini, A uhttps://forestphytophthoras.org/references/first-report-phytophthora-cactorum-associated-beech-decline-italy03083nas a2200169 4500008004100000022001400041245009000055210006900145260001600214300001400230490000700244520255200251100001302803700001302816700001402829856007002843 2014 eng d a0191-291700aFirst Report of Phytophthora tentaculata Causing Stem and Root Rot on Celery in China0 aFirst Report of Phytophthora tentaculata Causing Stem and Root R cJan-03-2014 a421 - 4210 v983 a

Celery (Apium graveolens) is an important vegetable in China. In August 2012, about 20 to 70% declining plants with root and basal stem rot were observed in Bengbu, Anhui Province, China. Typical symptoms included large dark brown to black water-soaked lesions near the soil line of stems. As the disease progressed, lesions girdled the stem, and plants became brown, wilted, and eventually died. A Phytophthora-like organism was consistently isolated from symptomatic tissues on a selective medium, P5ARP. Resultant isolates were identified as Phytophthora tentaculata based on their morphological features and rDNA sequence. Sporangia, chlamydospores, hyphal swellings, and oospores were produced on V8 agar. Sporangia were ovoid to pyriform, 28.5 to 52.5 × 21.5 to 40.6 μm, average 35.3 × 29.8 μm, with one or occasionally two papillae. Chlamydospores were spherical, 21.3 to 30.2 μm in diameter, average 25.7 μm. The isolates were homothallic, and one or occasionally two paragynous antheridia were attached to the global oogonia (24 to 39 μm in diameter, average 29.5 μm). The internal transcribed spacer region of rDNA was amplified with primer pair ITS1/ITS4 for one isolate (1), and the sequence (GenBank Accession No. KF501392) showed >99% similarity with those P. tentaculata isolates deposited in GenBank (AJ854302.1). Pathogenicity was confirmed by inoculating Shijihuangqin, a local cultivar of celery, with isolate PT12081. The isolate was cultivated on V8 agar at 25°C for 5 to 7 days to produce sporangia. Five 2-month-old, disease-free celery were drench-inoculated with 10 ml of a suspension of 2 × 104 zoospores/ml, and five control plants per pot were treated with sterile water. There were four pots for each of the inoculated and non-inoculated treatments, and the experiment was repeated twice. All plants were maintained at 25°C for 10 days. Symptoms similar to those observed in the field developed 7 days after inoculation. Ten days later, five plants wilted and two or three died in each pot inoculated with PT12081, but the control plants remained symptomless. P. tentaculata was consistently re-isolated from the symptomatic plants. P. tentaculata has been reported to infect Chrysanthemum spp., Delphinium ajacis, Verbena spp., and Origanum vulgare (2,3). To our knowledge, this is the first report of Phytophthora blight caused by P. tentaculata on celery in China.

1 aWang, T.1 aZhao, W.1 aQi, R.-D. uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-06-13-0592-PDN00457nas a2200085 4500008004100000245011800041210006900159100001800228856012500246 2005 eng d00aField validation of laboratory tests used in screening Port-Orford-cedar for resistance to Phytophthora lateralis0 aField validation of laboratory tests used in screening PortOrfor1 aWing, Adam, B uhttps://forestphytophthoras.org/references/field-validation-laboratory-tests-used-screening-port-orford-cedar-resistance01512nas a2200157 4500008004100000245009600041210006900137260001600206300001400222520100100236100001701237700001501254700002401269700001801293856004301311 2014 eng d00aFungi and oomycetes in open irrigation systems: knowledge gaps and biosecurity implications0 aFungi and oomycetes in open irrigation systems knowledge gaps an cJan-03-2014 an/a - n/a3 a

Water used for the irrigation of plants has the potential to harbour and spread plant pathogens yet little research is conducted within this field. This review was undertaken to critically review our understanding of water-borne fungal and oomycete plant pathogens in open irrigation systems, particularly in the context of plant biosecurity. It was determined that very limited data exists on these plant pathogens, with the majority of previous studies only recording pathogen presence. There are significant gaps in our knowledge of pathogen survival and spread, and very limited information on their ability to cause disease when contaminated irrigation water is applied to crops. This review has highlighted the need for new research on the epidemiology and pathogenicity of putative plant pathogens isolated from water, in order to determine their risk to crops. The importance of regular monitoring of irrigation systems for the early detection of plant pathogens is also discussed.

1 aZappia, R.E.1 aHuberli, D1 aHardy, G., E. St.J.1 aBayliss, K.L. uhttp://doi.wiley.com/10.1111/ppa.12223