Phytophthora ITS Clade 6 contains numerous informally designated taxa and recently described new ... more Phytophthora ITS Clade 6 contains numerous informally designated taxa and recently described new species. We report here on the characterisation of the two informally designated taxa P. taxon Forestsoil and P. sp. hungarica. The first culture of P. taxon Forestsoil was collected from soil of an oak‐ Carpinus forest in 1998 and partially characterised later [1]. Subsequently, a few isolates from alder soil with identical ITS sequences to P. t. Forestsoil were reported as P. sp. sylvatica and P. sp. H‐6/02 at Genbank in 2007. At the same time other isolates from alder soil, differing from P. t. Forestsoil and its synonyms in their colony pattern on carrot agar (CA) and at the same 4 positions in their ITS, were named P. sp. hungarica, P. sp. H‐7/02 and P. sp. H‐8/02. Additional ‘hungarica’ isolates were then collected in Alaska [2], also from alder soils or nearby waterways. In our detailed study, the only consistent morphological difference between ‘Forestsoil’ and ‘hungarica’ was st...
Acta Phytopathologica Et Entomologica Hungarica, 1998
ABSTRACT A collection of 49 isolates of Phytophthora infestans, collected from blighted potato fo... more ABSTRACT A collection of 49 isolates of Phytophthora infestans, collected from blighted potato foliage in 1998 in Flanders, were analysed for mating type, response to metalaxyl (48 isolates), allozymes of glucose-6-phosphate isomerase (Gpi), peptidase (Pep) and restriction fragment length polymorphism (RFLP) with probe RG57 (39 isolates). Forty-one A1 and eight A2 isolates were detected. Resistance to metalaxyl was frequently observed: 30 resistant, four intermediate and 14 sensitive isolates were found. Gpi genotypes 100/100 and 90/100 occurred in 30 and nine isolates, respectively. The dominating banding pattern for Pep was 100/100 (32 isolates), but genotypes 96/96, 96/100 and 83/96, never previously reported in continental western Europe, were also identified. Thirteen RG57 fingerprints were observed. On the basis of combined traits, 15 multilocus genotypes were revealed among 39 isolates. Genotypic diversity measured by the normalized Shannon diversity index was 0.56. The results indicate that, besides asexual variation and/or migration, sexual events may have played a role in the establishment of the isolates studied.
A gombaszerű, de algakkal rokon novenykorokozo Phytophthora-fajok vilagszerte sulyos karokat okoz... more A gombaszerű, de algakkal rokon novenykorokozo Phytophthora-fajok vilagszerte sulyos karokat okoznak mezőgazdasagi, kerteszeti es erdeszeti kulturakban. Magyarorszagon keves ismeretunk volt előfordulasuk gyakorisagarol, ezert celunk a hazai fitoftorak es az altaluk kivaltott betegsegek felmerese es a patogenek valtozekonysaganak tanulmanyozasa volt. Osszesen 18 fitoftorat (kozuluk 7-et hazai viszonylatban első alkalommal) azonositottunk 19 novenyfajrol (elsősorban disznovenyekről), erdők es gyumolcsosok talajabol, valamint 32 hazankban eddig le nem irt fitoftora-gazdanoveny kapcsolatot jegyeztunk fel. Leggyakoribb betegsegtunet a gyoker- es szartőrothadas volt, minek kovetkezteben az egesz noveny elpusztulhat. Hajtasokon es leveleken ritkabban fordultak elő e patogenek. EPPO karanten listas korokozokat nem azonositottunk. A beteg novenyek mintegy felet mindossze nehany kulonosen elterjedt faj karositotta. A mar korabban ismert korokozok mellett azonositottunk a tudomanyra nezve uj f...
During preliminary investigations in 2001, 57 fen type alder forests and riparian type alder fore... more During preliminary investigations in 2001, 57 fen type alder forests and riparian type alder forests were investigated over a distance of 100 km. Results of this investigation were reported by Koltay (2002) in Prague. Experimental plots are being established in 2002 in order to determine presence/ absence of the disease, and to measure the rate and intensity of the infection. Ten new plots have been established to date and another 10 plots will be established in the future (see map). Stands that contained more than 3% of infected trees in different age classes and of different origins were selected as experimental plots. All plots contain 50 sample trees with the exception of two plots which contain 100 trees. Up to now we have examined each site once per year, but beginning in 2003 we will visit the plots twice each year (late spring and autumn). Methods Used for Investigating the Incidence of Phytophthora Disease of Alder in Hungary A. Koltay1, J. Bakonyi2 and Z. Á. Nagy3
Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilu... more Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilum, as well as two formae of Drechslera teres were compared by RAPD analysis. Drechslera formed a large, heterologous group, while species of Bipolaris and Exserohilum were more closely related. Strong pair-wise affinities were observed between D. graminea and D. teres, D. tritici-repentis and D. bromi, D. siccans and D. biseptata, D. fugax and D. poae, B. sorghicola and B. zeicola, as well as between E. rostratum and E. turcicum.
A kutatas a fitoftoras egervesz korokozojaval, a P. alnival foglalkozik. E korokozo izolatumait 3... more A kutatas a fitoftoras egervesz korokozojaval, a P. alnival foglalkozik. E korokozo izolatumait 3 klonszerű alfajba soroljak. A P. alni szulőfajai feltehetően az egerre nem patogen P. cambivora es a P. fragariae. Celunk a hibridek es feltetelezett szulőfajaik genetikai valtozekonysaganak tanulmanyozasa volt. Kifejlesztettunk egy olyan DNS-re alapozott eljarast, mellyel a P. alni alfajai ketseget kizaro modon elkulonithetők egymastol es a feltetelezett szulőfajoktol. A modszer alkalmas a hibridek fertőzott novenyi mintakban valo kimutatasara. A mitokondrialis (mt)DNS-t tekintve 41 P. cambivora izolatum tizenhet, 19 P. fragariae izolatum negy, 25 P. alni torzs pedig ket haplotipust tartalmazott. Nem talaltunk a hibridekben es barmelyik szulőfajban kozos haplotipust. Regiok szerinti tagozodast sem figyeltunk meg. A P. fragariae szamocarol es malnarol szarmazo tenyeszetei viszont egyertelműen elkulonultek. A P. alni ssp. alni ketfele mintazatot tartalmazott. Egyik az egyontetű P. alni s...
The Valdivian rainforest, one of the global hotspots of biodiversity, is a temperate rainforest o... more The Valdivian rainforest, one of the global hotspots of biodiversity, is a temperate rainforest originating as a Tertiary relic from the supercontinent Gondwana. In November 2014, a survey of Phytophthora diversity was performed in 13 natural forest stands and 20 forest streams and rivers in two protected areas near Valdivia and in a temperate montane forest in the Concepcion area. One planted stand each of the introduced tree species Castanea sativa and Fagus sylvatica were also included. Using baiting assays, eight described species and four previously unknown taxa of Phytophthora were isolated from 86% of the 50 rhizosphere soil samples from seven of the eight tree species sampled in 12 forest stands, and from 20 streams: P. chlamydospora, P. cinnamomi, P. kernoviae, P. lacustris, P. plurivora, P. pseudosyringae, P. ×cambivora, P. ×stagnum, P. valdiviana nom. prov. from Clade 2b, P. madida nom. prov. from Clade 8a, and P. chilensis nom. prov. and P. pseudokernoviae nom. prov. The latter two species are the closest relatives of P. kernoviae from Clade 10. Phytophthora pseudokernoviae nom. prov. was also isolated from necrotic leaves of Drimys winteri. From the Valdivia river, a swarm of three Clade 6 hybrids was recovered. Each hybrid isolate resulted from multiple reticulation events with P. thermophila as maternal and both P. amnicola and P. chlamydospora as paternal parents. In addition, three previously unknown and recently described Nothophytophthora species, N. caduca, N. chlamydospora and N. valdiviana, were isolated from several forest streams. Phytophthora cinnamomi, the most common and widespread species in soils of native forests, was associated with severe dieback of Valdivian rainforest trees, in particular D. winteri, Luma apiculata, Nothofagus dombeyi and the endangered Saxegothaea conspicua. A first pathogenicity test demonstrated high aggressiveness of P. cinnamomi to several native tree species, including N. dombeyi, Blepharocalyx cruckshanksii and Gevuina avellana.
Efficiency of three fungicides in leaf disc assays against Phytophthora infestans isolates from f... more Efficiency of three fungicides in leaf disc assays against Phytophthora infestans isolates from fields with different late blight management TERÉZIA DULA1, ZOLTÁN SIMON2, KATALIN TEMESVÁRY3, ZOLTÁN Á. NAGY4*, KATALIN SIMON3, ISTVÁN WOLF5, ZSOLT ...
A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from ... more A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia,
Phytophthora ITS Clade 6 contains numerous informally designated taxa and recently described new ... more Phytophthora ITS Clade 6 contains numerous informally designated taxa and recently described new species. We report here on the characterisation of the two informally designated taxa P. taxon Forestsoil and P. sp. hungarica. The first culture of P. taxon Forestsoil was collected from soil of an oak‐ Carpinus forest in 1998 and partially characterised later [1]. Subsequently, a few isolates from alder soil with identical ITS sequences to P. t. Forestsoil were reported as P. sp. sylvatica and P. sp. H‐6/02 at Genbank in 2007. At the same time other isolates from alder soil, differing from P. t. Forestsoil and its synonyms in their colony pattern on carrot agar (CA) and at the same 4 positions in their ITS, were named P. sp. hungarica, P. sp. H‐7/02 and P. sp. H‐8/02. Additional ‘hungarica’ isolates were then collected in Alaska [2], also from alder soils or nearby waterways. In our detailed study, the only consistent morphological difference between ‘Forestsoil’ and ‘hungarica’ was st...
Acta Phytopathologica Et Entomologica Hungarica, 1998
ABSTRACT A collection of 49 isolates of Phytophthora infestans, collected from blighted potato fo... more ABSTRACT A collection of 49 isolates of Phytophthora infestans, collected from blighted potato foliage in 1998 in Flanders, were analysed for mating type, response to metalaxyl (48 isolates), allozymes of glucose-6-phosphate isomerase (Gpi), peptidase (Pep) and restriction fragment length polymorphism (RFLP) with probe RG57 (39 isolates). Forty-one A1 and eight A2 isolates were detected. Resistance to metalaxyl was frequently observed: 30 resistant, four intermediate and 14 sensitive isolates were found. Gpi genotypes 100/100 and 90/100 occurred in 30 and nine isolates, respectively. The dominating banding pattern for Pep was 100/100 (32 isolates), but genotypes 96/96, 96/100 and 83/96, never previously reported in continental western Europe, were also identified. Thirteen RG57 fingerprints were observed. On the basis of combined traits, 15 multilocus genotypes were revealed among 39 isolates. Genotypic diversity measured by the normalized Shannon diversity index was 0.56. The results indicate that, besides asexual variation and/or migration, sexual events may have played a role in the establishment of the isolates studied.
A gombaszerű, de algakkal rokon novenykorokozo Phytophthora-fajok vilagszerte sulyos karokat okoz... more A gombaszerű, de algakkal rokon novenykorokozo Phytophthora-fajok vilagszerte sulyos karokat okoznak mezőgazdasagi, kerteszeti es erdeszeti kulturakban. Magyarorszagon keves ismeretunk volt előfordulasuk gyakorisagarol, ezert celunk a hazai fitoftorak es az altaluk kivaltott betegsegek felmerese es a patogenek valtozekonysaganak tanulmanyozasa volt. Osszesen 18 fitoftorat (kozuluk 7-et hazai viszonylatban első alkalommal) azonositottunk 19 novenyfajrol (elsősorban disznovenyekről), erdők es gyumolcsosok talajabol, valamint 32 hazankban eddig le nem irt fitoftora-gazdanoveny kapcsolatot jegyeztunk fel. Leggyakoribb betegsegtunet a gyoker- es szartőrothadas volt, minek kovetkezteben az egesz noveny elpusztulhat. Hajtasokon es leveleken ritkabban fordultak elő e patogenek. EPPO karanten listas korokozokat nem azonositottunk. A beteg novenyek mintegy felet mindossze nehany kulonosen elterjedt faj karositotta. A mar korabban ismert korokozok mellett azonositottunk a tudomanyra nezve uj f...
During preliminary investigations in 2001, 57 fen type alder forests and riparian type alder fore... more During preliminary investigations in 2001, 57 fen type alder forests and riparian type alder forests were investigated over a distance of 100 km. Results of this investigation were reported by Koltay (2002) in Prague. Experimental plots are being established in 2002 in order to determine presence/ absence of the disease, and to measure the rate and intensity of the infection. Ten new plots have been established to date and another 10 plots will be established in the future (see map). Stands that contained more than 3% of infected trees in different age classes and of different origins were selected as experimental plots. All plots contain 50 sample trees with the exception of two plots which contain 100 trees. Up to now we have examined each site once per year, but beginning in 2003 we will visit the plots twice each year (late spring and autumn). Methods Used for Investigating the Incidence of Phytophthora Disease of Alder in Hungary A. Koltay1, J. Bakonyi2 and Z. Á. Nagy3
Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilu... more Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilum, as well as two formae of Drechslera teres were compared by RAPD analysis. Drechslera formed a large, heterologous group, while species of Bipolaris and Exserohilum were more closely related. Strong pair-wise affinities were observed between D. graminea and D. teres, D. tritici-repentis and D. bromi, D. siccans and D. biseptata, D. fugax and D. poae, B. sorghicola and B. zeicola, as well as between E. rostratum and E. turcicum.
A kutatas a fitoftoras egervesz korokozojaval, a P. alnival foglalkozik. E korokozo izolatumait 3... more A kutatas a fitoftoras egervesz korokozojaval, a P. alnival foglalkozik. E korokozo izolatumait 3 klonszerű alfajba soroljak. A P. alni szulőfajai feltehetően az egerre nem patogen P. cambivora es a P. fragariae. Celunk a hibridek es feltetelezett szulőfajaik genetikai valtozekonysaganak tanulmanyozasa volt. Kifejlesztettunk egy olyan DNS-re alapozott eljarast, mellyel a P. alni alfajai ketseget kizaro modon elkulonithetők egymastol es a feltetelezett szulőfajoktol. A modszer alkalmas a hibridek fertőzott novenyi mintakban valo kimutatasara. A mitokondrialis (mt)DNS-t tekintve 41 P. cambivora izolatum tizenhet, 19 P. fragariae izolatum negy, 25 P. alni torzs pedig ket haplotipust tartalmazott. Nem talaltunk a hibridekben es barmelyik szulőfajban kozos haplotipust. Regiok szerinti tagozodast sem figyeltunk meg. A P. fragariae szamocarol es malnarol szarmazo tenyeszetei viszont egyertelműen elkulonultek. A P. alni ssp. alni ketfele mintazatot tartalmazott. Egyik az egyontetű P. alni s...
The Valdivian rainforest, one of the global hotspots of biodiversity, is a temperate rainforest o... more The Valdivian rainforest, one of the global hotspots of biodiversity, is a temperate rainforest originating as a Tertiary relic from the supercontinent Gondwana. In November 2014, a survey of Phytophthora diversity was performed in 13 natural forest stands and 20 forest streams and rivers in two protected areas near Valdivia and in a temperate montane forest in the Concepcion area. One planted stand each of the introduced tree species Castanea sativa and Fagus sylvatica were also included. Using baiting assays, eight described species and four previously unknown taxa of Phytophthora were isolated from 86% of the 50 rhizosphere soil samples from seven of the eight tree species sampled in 12 forest stands, and from 20 streams: P. chlamydospora, P. cinnamomi, P. kernoviae, P. lacustris, P. plurivora, P. pseudosyringae, P. ×cambivora, P. ×stagnum, P. valdiviana nom. prov. from Clade 2b, P. madida nom. prov. from Clade 8a, and P. chilensis nom. prov. and P. pseudokernoviae nom. prov. The latter two species are the closest relatives of P. kernoviae from Clade 10. Phytophthora pseudokernoviae nom. prov. was also isolated from necrotic leaves of Drimys winteri. From the Valdivia river, a swarm of three Clade 6 hybrids was recovered. Each hybrid isolate resulted from multiple reticulation events with P. thermophila as maternal and both P. amnicola and P. chlamydospora as paternal parents. In addition, three previously unknown and recently described Nothophytophthora species, N. caduca, N. chlamydospora and N. valdiviana, were isolated from several forest streams. Phytophthora cinnamomi, the most common and widespread species in soils of native forests, was associated with severe dieback of Valdivian rainforest trees, in particular D. winteri, Luma apiculata, Nothofagus dombeyi and the endangered Saxegothaea conspicua. A first pathogenicity test demonstrated high aggressiveness of P. cinnamomi to several native tree species, including N. dombeyi, Blepharocalyx cruckshanksii and Gevuina avellana.
Efficiency of three fungicides in leaf disc assays against Phytophthora infestans isolates from f... more Efficiency of three fungicides in leaf disc assays against Phytophthora infestans isolates from fields with different late blight management TERÉZIA DULA1, ZOLTÁN SIMON2, KATALIN TEMESVÁRY3, ZOLTÁN Á. NAGY4*, KATALIN SIMON3, ISTVÁN WOLF5, ZSOLT ...
A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from ... more A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia,
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