Abstract
Fungicide resistance has previously been reported within Australian vineyards: in Erysiphe necator (powdery mildew) to the demethylation inhibiting (DMI) and QoI (strobilurin) group of fungicides, inBotrytis cinerea to the dicarboximide and
anilinopyrimidine fungicide groups and in Plasmopara viticola (downy mildew) to metalaxyl. To determine the incidence and severity of fungicide resistance, samples of all three diseases were collected fromvineyards in the main viticultural regions of Australia and tested against a range of commonly used fungicides. The pathogens were tested phenotypically for resistance using leaf disc assays (E.necator and P. viticola ) or mycelial growth assays (B. cinerea ). Representative
samples were genotyped for the presence of known mutations conferring resistance. Phenotypic resistance ofE. necator to QoI was found in 42% of 72 isolates, with the G143A allele presentin 87% of 46 tested isolates. Phenotypic
resistance of E. necator to DMIs was not observed, however the Y136F allele was present in ~77% of the isolates.B. cinerea resistant populations to fenhexamid, iprodione, boscalid and pyrimethanil were detected in 7, 20, 21, and 27% respectively of the 72 sites tested. While54% of sites had no resistance detected, two sites had populations resistant to all four fungicides. A number of mutations were found in the target genes; H272R orH272Y in the sdhB gene (boscalid
target), I365S or Q369P/N373S in the bos-1gene (iprodione target) and F412S in the erg27 gene (fenhexamid target). Populations of P. viticola resistant to metalaxyl now exist in Western Australia and Tasmania as well as Victoria and New South Wales. The results of the testing haveconfirmed the presence of resistant populations of these three pathogens to many fungicides throughout Australia. However more work is needed to confirmhow these laboratory results relate to
field performance of fungicides in spray programmes.
anilinopyrimidine fungicide groups and in Plasmopara viticola (downy mildew) to metalaxyl. To determine the incidence and severity of fungicide resistance, samples of all three diseases were collected fromvineyards in the main viticultural regions of Australia and tested against a range of commonly used fungicides. The pathogens were tested phenotypically for resistance using leaf disc assays (E.necator and P. viticola ) or mycelial growth assays (B. cinerea ). Representative
samples were genotyped for the presence of known mutations conferring resistance. Phenotypic resistance ofE. necator to QoI was found in 42% of 72 isolates, with the G143A allele presentin 87% of 46 tested isolates. Phenotypic
resistance of E. necator to DMIs was not observed, however the Y136F allele was present in ~77% of the isolates.B. cinerea resistant populations to fenhexamid, iprodione, boscalid and pyrimethanil were detected in 7, 20, 21, and 27% respectively of the 72 sites tested. While54% of sites had no resistance detected, two sites had populations resistant to all four fungicides. A number of mutations were found in the target genes; H272R orH272Y in the sdhB gene (boscalid
target), I365S or Q369P/N373S in the bos-1gene (iprodione target) and F412S in the erg27 gene (fenhexamid target). Populations of P. viticola resistant to metalaxyl now exist in Western Australia and Tasmania as well as Victoria and New South Wales. The results of the testing haveconfirmed the presence of resistant populations of these three pathogens to many fungicides throughout Australia. However more work is needed to confirmhow these laboratory results relate to
field performance of fungicides in spray programmes.
| Original language | English |
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| Title of host publication | Proceedings of the 18th International Reinhardsbrunn Symposium April 24-28, 2016, Friedrichroda, Germany |
| Publisher | Deutsche Phytomedizinische Gesellschaft |
| Pages | 181-186 |
| Number of pages | 6 |
| ISBN (Electronic) | 9783941261150 |
| Publication status | Published - 2017 |
| Event | 18th International Reinhardsbrunn Symposium: Modern Fungicides and Antifungal Compounds - Friedrichroda, Germany, Germany Duration: 24 Apr 2016 → 28 Apr 2016 |
Publication series
| Name | Modern fungicides and antifungal compounds VIII |
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Conference
| Conference | 18th International Reinhardsbrunn Symposium: Modern Fungicides and Antifungal Compounds |
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| Country/Territory | Germany |
| Period | 24/04/16 → 28/04/16 |