02274nas a2200217 4500008004100000022001300041245012800054210006900182260001600251300001400267490000800281520155000289100001901839700002401858700002201882700002701904700002601931700002701957700002301984856004902007 2013 eng d a1878614600aCharacterization of Phytophthora hybrids from ITS clade 6 associated with riparian ecosystems in South Africa and Australia0 aCharacterization of Phytophthora hybrids from ITS clade 6 associ cJan-05-2013 a329 - 3470 v1173 a

Surveys of Australian and South African rivers revealed numerous Phytophthora isolates residing in clade 6 of the genus, with internal transcribed spacer (ITS) gene regions that were either highly polymorphic or unsequenceable. These isolates were suspected to be hybrids. Three nuclear loci, the ITS region, two single copy loci (antisilencing factor (ASF) and G protein alpha subunit (GPA)), and one mitochondrial locus (cytochrome oxidase c subunit I (coxI)) were amplified and sequenced to test this hypothesis. Abundant recombination within the ITS region was observed. This, combined with phylogenetic comparisons of the other three loci, confirmed the presence of four different hybrid types involving the three described parent species Phytophthora amnicola, Phytophthora thermophila, and Phytophthora taxon PgChlamydo. In all cases, only a single coxI allele was detected, suggesting that hybrids arose from sexual recombination. All the hybrid isolates were sterile in culture and all their physiological traits tended to resemble those of the maternal parents. Nothing is known regarding their host range or pathogenicity. Nonetheless, as several isolates from Western Australia were obtained from the rhizosphere soil of dying plants, they should be regarded as potential threats to plant health. The frequent occurrence of the hybrids and their parent species in Australia strongly suggests an Australian origin and a subsequent introduction into South Africa.

1 aNagel, Jan, H.1 aGryzenhout, Marieka1 aSlippers, Bernard1 aWingfield, Michael, J.1 aHardy, Giles, E.St.J.1 aStukely, Michael, J.C.1 aBurgess, Treena, I uhttps://doi.org/10.1016/j.funbio.2013.03.00401739nas a2200193 4500008004100000022001400041245012000055210006900175260002900244300001400273490000700287520111500294100001501409700001901424700001401443700001801457700001501475856005501490 2011 eng d a1439-032900aRelationship between field resistance to Phytophthora ramorum and constitutive phenolic chemistry of coast live oak0 aRelationship between field resistance to Phytophthora ramorum an bBlackwell Publishing Ltd a464–4690 v413 a

Sudden oak death, caused by Phytophthora ramorum, has resulted in high levels of coast live oak (CLO) mortality. However, some CLO survive in areas with high disease pressure and may thus be resistant. We tested the hypothesis that such field-resistant trees contain constitutively higher levels of phenolics than susceptible trees. Phloem was sampled from the trunks of two groups of trees (one previously inoculated, one naturally infected with P. ramorum) categorized over the course of several years as putatively resistant (PR, no symptoms), in remission (IR, showed symptoms but then recovered) and symptomatic (S). Individual and total soluble phenolics from these trees were quantified. There were no significant differences in individual or total soluble phenolics between groups of naturally infected trees. However, inoculated PR and IR trees were characterized by higher constitutive levels of ellagic acid, a tyrosol derivative, and an unidentified phenolic than S trees. Ellagic acid and tyrosol-like compounds in CLO phloem are promising resistance biomarker candidates.

1 aNagle, A M1 aMcpherson, B A1 aWood, D L1 aGarbelotto, M1 aBonello, P uhttp://dx.doi.org/10.1111/j.1439-0329.2010.00703.x00484nas a2200109 4500008004100000245009200041210006900133250001500202260009200217100001000309856005500319 2006 eng d00aPhytophthora alni (Brasier et al.) update on alder Phytophthora and potential new hosts0 aPhytophthora alni Brasier et al update on alder Phytophthora and a04/05/2006 bNorth American Plant Protection Organization, NSF Center for Integrated Pest Management1 aNAPPO uhttp://www.pestalert.org/viewNewsAlert.cfm?naid=1502787nas a2200169 4500008004100000245009400041210006900135260001600204300001400220490000700234520215500241100001602396700001302412700001502425700001602440856016102456 2015 eng d00aPathogenicity to alder of Phytophthora species from riparian ecosystems in western Oregon0 aPathogenicity to alder of Phytophthora species from riparian eco cJan-10-2015 a358 - 3660 v453 a

Described as one of the most destructive pathogens of agricultural crops and forest trees, Phytophthora is a genus of microorganisms containing over 100 known species. Phytophthora alni has caused collar and root disease in alders throughout Europe, and a subspecies has recently been isolated in North America. Reports of canopy dieback in red alder, Alnus rubra, prompted a survey of their overall health and to determine whether P. alni was present in western Oregon riparian ecosystems. Over 1100 Phytophthora isolates were recovered, representing 20 species and 2 taxa. Phytophthora-type cankers were observed in many trees, and their incidence was positively correlated with canopy dieback. High levels of mortality for red alder were not observed, which suggests these Phytophthora species are not aggressive pathogens. To test this hypothesis, three stem wound inoculations and one root dip were conducted on red alder seedlings using 13 Phytophthora species recovered from the riparian survey. Ten of the 13 Phytophthora species produced significant lesions in at least one pathogenicity test. Phytophthora siskiyouensis produced the largest lesions on red alder from the two stem wound inoculation tests conducted under summer conditions, while P. taxon Pgchlamydo caused the largest lesions during the winter stem wound inoculation test. Phytophthora gonapodyides, P. taxon Pgchlamydo and P. siskiyouensis have previously been found associated with necrotic alder roots and bole cankers in the field, and with the pathogenicity results reported here, we have established these species as causes of Phytophthora root disease and Phytophthora bole canker of alder in Oregon. While none of the Phytophthora species were especially aggressive towards red alder in the pathogenicity tests, they did cause localized disease symptoms. By weakening the root systems or boles of alders, the Phytophthoras could be leaving alders more susceptible to other insects and pathogens.

1 aNavarro, S.1 aSims, L.1 aHansen, E.1 aVannini, Á uhttp://doi.wiley.com/10.1111/efp.2015.45.issue-5http://doi.wiley.com/10.1111/efp.12175http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fefp.1217502022nas a2200217 4500008004100000022001300041245012500054210006900179260001100248300001400259490000700273520135100280100002101631700001301652700001301665700001401678700001501692700001301707700001301720856007101733 2004 eng d a0261219400aImpact of removing diseased pods on cocoa black pod caused by Phytophthora megakarya and on cocoa production in Cameroon0 aImpact of removing diseased pods on cocoa black pod caused by Ph c5/2004 a415 - 4240 v233 a

Black pod rot, caused by Phytophthora megakarya, is the main cause of cocoa harvest losses in Cameroon. Field experiments were carried out over two successive years in two smallholders’ plots of cocoa trees, in order to assess the impact of diseased pod removal (phytosanitary pod removal) on disease progress, total production and final harvest. The generalized linear mixed model proved to be the most appropriate for comparing the two treatments (without and with pod removal) set up in a randomized complete block design. Removing diseased pods helped to reduce the black pod rate by 22% and 31% in the two sites in the first year, and by 9% and 11% in the second year, compared to a plot in which no preventive control measures were taken. The rate of cherelle (very young pod) appearance was also higher when pod removal was carried out. Total production was higher in the plots with pod removal, but the difference between the two treatments was not significant. This study allowed an evaluation of the respective roles of primary and secondary inoculum in the spread of the disease. The cultural practice of phytosanitary pod removal was found to be a potentially efficient control method. However, it would need to be associated with other control methods to establish an integrated management system for cocoa farmers.

1 aNdoumbe-Nkeng, M1 aCilas, C1 aNyemb, E1 aNyasse, S1 aBieysse, D1 aFlori, A1 aSache, I uhttp://www.sciencedirect.com/science/article/pii/S026121940300237002612nas a2200301 4500008004100000022001400041245014300055210006900198260003800267300001400305520168700319653001002006653001402016653002902030653001102059653002102070653001802091100001702109700001502126700001802141700001702159700001202176700001502188700001602203700001902219700001702238856005502255 2012 eng d a1365-305900aThe morphology, behaviour and molecular phylogeny of Phytophthora taxon Salixsoil and its redesignation as Phytophthora lacustris sp. nov.0 amorphology behaviour and molecular phylogeny of Phytophthora tax bBlackwell Publishing Ltdc04/2013 a355–3693 a

Since its first isolation from Salix roots in 1972, isolates of a sexually sterile Phytophthora species have been obtained frequently from wet or riparian habitats worldwide and have also been isolated from roots of Alnus and Prunus spp. Although originally assigned to Phytophthora gonapodyides on morphological grounds, it was recognized that these isolates, informally named P. taxon Salixsoil, might represent a separate lineage within ITS Clade 6. Based on phylogenetic analyses and comparisons of morphology, growth-temperature relationships and pathogenicity, this taxon is formally described here as Phytophthora lacustris sp. nov. Isolates of P. lacustris form a clearly resolved cluster in both ITS and mitochondrial cox1 phylogenies, basal to most other Clade 6 taxa. Phytophthora lacustris shares several unusual behavioural properties with other aquatic Clade 6 species, such as sexual sterility and tolerance of high temperatures, that have been suggested as adaptations to riparian conditions. It appears to be widespread in Europe and has also been detected in Australia, New Zealand and the USA. It was shown to be weakly or moderately aggressive on inoculation to Alnus, Prunus and Salix. The extent of P. lacustris’ activity as a saprotroph in plant debris in water and as an opportunistic pathogen in riparian habitats needs further investigation. Its pathogenic potential to cultivated fruit trees also deserves attention because P. lacustris has apparently been introduced into the nursery trade.

10aAlnus10aphylogeny10aPhytophthora ITS Clade 610aPrunus10ariparian habitat10atree pathogen1 aNechwatal, J1 aBakonyi, J1 aCacciola, S O1 aCooke, D E L1 aJung, T1 aNagy, Z Á1 aVannini, Á1 aVettraino, A M1 aBrasier, C M uhttp://dx.doi.org/10.1111/j.1365-3059.2012.02638.x02272nas a2200193 4500008004100000022001400041245014000055210006900195300001000264490000700274520156900281100001701850700001701867700001201884700001701896700001601913700001501929856013401944 2001 eng d a1437-478100aA combination of baiting and PCR techniques for the detection of Phytophthora quercina and P. citricola in soil samples from oak stands0 acombination of baiting and PCR techniques for the detection of P a85-970 v313 a

Es wird der spezifische Nachweis von Phytophthora quercina und P. citricola in Bodenproben von absterbenden Eichen mit Hilfe einer Kombination von PCR- Reaktionen mit artspezifischen Primern erlaubten den Nachweis von P. quercina und P. citricola in den infizierten Eichenblaettern aus diesen Tests und im jeweiligen 'Baiting-Wasser'. Der PCR- und Baiting-Methoden beschrieben. Die Bodenproben wurden mit Wasser geflutet und Baiting-Tests unterzogen, bei denen junge Blaettchen von Quercus robur als Koeder zum Einsatz kamen. Einfache oder nested PCR-Nachweis beider Erreger war auch moeglich, wenn Bodenproben gruendlich mit Wasser gemischt wurden, das aufgeschwemmte organische Material abgesammelt und das Wasser abgenommen wurde. P. quercina und P. citricola wurden dabei in nahezu allen Faellen im Wasser, jedoch weniger regelmaessig im organischen Material nachgewiesen. Die Identitaet der betreffenden Arten wurde zusaetzlich durch Restriktions-Analysen der entsprechenden Amplicons bestaetigt. Ausserdem wurde die Anwesenheit beider Arten in den untersuchten Bodenproben durch klassische Baiting-Methoden nachgewiesen. Nested PCR mit den verwendeten Primaerpaaren erlaubte den Nachweis von nur 5 Zoosporen von P. citricola und 300 Zoosporen von P. quercina in einem Gesamt-Volumen von 100 My l. Die beschriebenen Methoden ermoeglichen Nachweis und Identifizierung von Phytophthora-Arten in Bodenproben, ohne die Notwendigkeit einer direkten Extraktion des Bodens und ohne weitreichende Kenntnis der morphologischen Merkmale der Arten dieser Gattung.

1 aNechwatal, J1 aSchlenzig, A1 aJung, T1 aCooke, D E L1 aDuncan, J M1 aOßwald, W uhttps://forestphytophthoras.org/references/combination-baiting-and-pcr-techniques-detection-phytophthora-quercina-and-p-citricola02303nas a2200181 4500008004100000022001400041245010400055210006900159260002900228300001400257490000700271520172200278100001702000700001202017700002202029700001502051856005502066 2011 eng d a1439-032900aA twig blight of understorey European beech (Fagus sylvatica) caused by soilborne Phytophthora spp.0 atwig blight of understorey European beech Fagus sylvatica caused bBlackwell Publishing Ltd a493–5000 v413 a

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

1 aNechwatal, J1 aHahn, J1 aSch√∂nborn, A1 aSchmitz, G uhttp://dx.doi.org/10.1111/j.1439-0329.2011.00711.x00555nas a2200133 4500008004100000245011100041210006900152300001400221490000700235100001400242700001500256700001400271856013600285 2010 eng d00aPrevalence, distribution and identification of Phytophthora species from bleeding canker on European beech0 aPrevalence distribution and identification of Phytophthora speci a150–1580 v281 aNelson, A1 aWeiland, G1 aHudler, G uhttps://forestphytophthoras.org/references/prevalence-distribution-and-identification-phytophthora-species-bleeding-canker-european00616nas a2200121 4500008004100000245008500041210006900126300001200195490001000207100001600217700001600233856024500249 2007 eng d00aA summary of North American hardwood tree diseases with bleeding canker symptoms0 asummary of North American hardwood tree diseases with bleeding c a122-1310 v33(2)1 aNelson, A H1 aHudler, G W uhttp://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=57&ved=0CE4QFjAGODI&url=http%3A%2F%2Fjoa.isa-arbor.com%2Frequest.asp%3FJournalID%3D1%26ArticleID%3D2985%26Type%3D2&ei=pKOvUpvjGcv7oASXoYDYDA&usg=AFQjCNHxNzEH7As_NfGpUf1LVGxbCXIeXA00320nas a2200109 4500008004100000245004700041210004600088300001200134490000800146100001700154856003900171 1961 eng d00aNon-lethal pathological infection of roots0 aNonlethal pathological infection of roots a615-6160 v1911 aNewhook, F J uhttp://dx.doi.org/10.1038/191615a002576nas a2200277 4500008004100000022001400041245012600055210006900181260002900250300001600279490000700295520170800302653003202010653002602042653001602068653002402084100001302108700001702121700001302138700002702151700001902178700001402197700001702211700001502228856005502243 2011 eng d a1365-305900aPotential for eradication of the exotic plant pathogens Phytophthora kernoviae and Phytophthora ramorum during composting0 aPotential for eradication of the exotic plant pathogens Phytopht bBlackwell Publishing Ltd a1077–10850 v603 a

Temperature and exposure time effects on Phytophthora kernoviae and Phytophthora ramorum viability were examined in flasks of compost and in a large-scale composting system containing plant waste. Cellophane, rhododendron leaf and peat-based inoculum of P. kernoviae and P. ramorum isolates were used in flasks; naturally infected leaves were inserted into a large-scale system. Exposures of 5 and 10 days respectively at a mean temperature of 35°C in flask and large-scale composts reduced P. kernoviae and P. ramorum inocula to below detection limits using semi-selective culturing. Although P. ramorum was undetectable after a 1-day exposure of inoculum to compost at 40°C in flasks, it survived on leaves exposed to a mean temperature of 40·9°C for 5 days in a large-scale composting system. No survival of P. ramorum was detected after exposure of infected leaves for 5 days to a mean temperature of >=41·9°C (32·8°C for P. kernoviae) or for 10 days at >=31·8°C (25·9°C for Phytophthora pseudosyringae on infected bilberry stems) in large-scale systems. Fitted survival probabilities of P. ramorum on infected leaves exposed in a large-scale system for 5 days at 45°C or for 10 days at 35°C were <3%, for an average initial infection level of leaves of 59·2%. RNA quantification to measure viability was shown to be unreliable in environments that favour RNA preservation: high levels of ITS1 RNA were recovered from P. kernoviae- and P. ramorum-infected leaves exposed to composting plant wastes at >53°C, when all culture results were negative.

10aPhytophthora pseudosyringae10aRhododendron ponticum10atemperature10aVaccinium myrtillus1 aNoble, R1 aBlackburn, J1 aThorp, G1 aDobrovin-Pennington, A1 aPietravalle, S1 aKerins, G1 aAllnutt, T R1 aHenry, C M uhttp://dx.doi.org/10.1111/j.1365-3059.2011.02476.x01817nas a2200157 4500008004100000245008000041210006900121260001600190520132800206100002301534700001701557700001501574700001401589700001601603856004001619 2016 eng d00aRapid diagnosis of pathogenic Phytophthora species in soil by real-time PCR0 aRapid diagnosis of pathogenic Phytophthora species in soil by re cJan-07-20163 a

Real-time PCR assays based on the TaqMan system and using ITS sequences were developed for the identification of Phytophthora species, including P. cactorum, P. megasperma, P. plurivora, P. pseudosyringae and P. quercina, all of which are currently causing significant damage to roots of forest trees in both managed stands and natural ecosystems. Total genomic DNA was extracted from mycelia of aforementioned Phytophthora isolates. Species-specific primers for P. cactorum, P. megasperma, P. plurivora, P. pseudosyringae and P. quercina were designed based on ITS sequences of rDNA. The amplification efficiency of target DNA varied from 93.1% (P. pseudosyringae) to 106.8% (P. quercina). The limit of the detection was calculated as 100 – 1,000 fg DNA, depending on the Phytophthora species. In mixed soil samples, all Phytophthora species were detected for Ct values shifted by 0.7 – 2.1 cycles. Based on these real-time PCR assays we were able to identify the five Phytophthora species. These techniques will be of value in the identification of these pathogens, which may cause up to 80 – 90% fine root loss in oak stands.

1 aNowakowska, J., A.1 aMalewski, T.1 aTereba, A.1 aOszako, T1 aBelbahri, L uhttp://dx.doi.org/10.1111/efp.1230301958nas a2200217 4500008004100000022001300041245010400054210006900158260001200227300001600239490000800255520129900263100001501562700001401577700002001591700001301611700001301624700001401637700001801651856007101669 1999 eng d a0953756200aDiversity of Phytophthora megakarya in Central and West Africa revealed by isozyme and RAPD markers0 aDiversity of Phytophthora megakarya in Central and West Africa r c10/1999 a1225 - 12340 v1033 a

Phytophthora megakarya is an important pathogen of cocoa in Africa. We used isozyme and RAPD markers to estimate the genetic diversity and structuring among 161 isolates, from the known distribution area of the fungus which corresponds to the cocoa belt in Ghana, Togo, Nigeria, Cameroon, Gabon and Sao Tome. Thirty six and 44 multilocus patterns were identified with isozymes and RAPDs, respectively. Patterns were separated into two highly differentiated genetic groups with both types of markers, one located in Central Africa and the other in West Africa. This distribution coincides with two major biogeographical domains which may reflect an ancient evolution of P. megakarya in this part of Africa. The genotypic diversity was lower in West Africa as compared to Central Africa. Inside Central Africa, isolates from Gabon and Sao Tome were highly differentiated based on RAPDs. Four intermediate marker patterns corresponding to isolates sampled near the border between Nigeria and Cameroon were putatively derived from genetic exchanges between the two major groups. The mating type determination permitted to confirm the high prevalence of A1 over A2. Although clonal multiplication seems to be the rule, indices of other reproduction means have been detected.

1 aNyassÉ, S1 aGrivet, L1 aRisterucci, A M1 aBlaha, G1 aBerry, D1 aLanaud, C1 aDesprÉAux, D uhttp://www.sciencedirect.com/science/article/pii/S0953756208606711