Incidence and distribution of Botryosphaeriaceae species associated with dieback in walnut orchards in Australia

Abstract Fungi belonging to the family Botryosphaeriaceae have been implicated in significant economic loss many horticultural crops worldwide. These fungal pathogens pose an emerging risk productivity of Australian walnut industry, although which species are present is unknown. To address this knowledge gap, tissues were collected from 14 orchards representing major walnut‐growing regions Australia, and isolations performed. recovered both symptomatic asymptomatic samples nine orchards. DNA sequencing confirmed presence five species, namely Diplodia seriata , Dothiorella omnivora Neofusicoccum parvum N . macroclavatum Spencermartinsia viticola Of 106 isolates recovered, D most prevalent species. Pathogenicity studies using detached stems indicated that spp. virulent followed by This first systematic study on incidence, identification pathogenicity Australia.