Identification and distribution of the Botryosphaeriaceae associated with grapevine decline in south-eastern Australia

Botryosphaeriaceae species are recognised as importantpathogens of grapevines both in Australia andoverseas. The identity, prevalence, and distribution ofBotryosphaeriaceae species in vineyards throughoutthe major winegrowing regions of New South Wales(NSW) and South Australia (SA) was determined toprovide a foundation for improved disease preventionand management. Field surveys from 91 vineyardsacross NSW and SA resulted in the collection of2239 diseased wood samples and subsequent isolationof 1258 Botryosphaeriaceae isolates. Morphologicalidentification along with phylogenetic analysis of ribosomalDNA internal transcribed spacer regions (ITS1-5.8S-ITS2) and partial sequences of the translationelongation factor 1-' gene (EF1-') showed that eightBotryosphaeriaceae species including Diplodia seriata,Diplodia mutila, Lasiodiplodia theobromae, Neofusicoccumparvum, Neofusicoccum australe, Botryosphaeriadothidea, Dothiorella viticola, and Dothiorellaiberica occur on grapevines in south-eastern Australia.The prevalence of individual species varied accordingto geography and climate. Species of Diplodia andDothiorella, characterised by thick-walled, pigmentedconidia were the most prevalent and were distributedwidely throughout both NSW and SA. Species withhyaline conidia, such as Neofusicoccum and Fusicoccum,were isolated less frequently and displayed morelimited geographic ranges, whilst only a single isolateof Lasiodiplodia was recovered, this being from thenorthern most region of NSW. Other trunk disease fungiisolated included Phomopsis viticola, Phaeomoniellachlamydospora, Eutypa lata and other diatrypaceousspecies. We have established a sound base for controlstrategies based on the prevailing species in Australianviticultural regions.