Hymenochaetales associated with esca-related wood rots on grapevine with a special emphasis on the status of esca in South African vineyards

Abstract

Esca disease is a problem on grapevines worldwide. This disease complex is characterised by several external and internal symptoms including foliar tiger-stripe chlorosis and necrosis, dieback, wood necrosis and white rot. The causal organisms of esca are primarily Phaeomoniella chlamydospora, several Phaeoacremonium species and basidiomycete species from the order Hymenochaetales, the latter ones responsible for causing the white rot symptom. Basidiomycete species causing the wood rot symptom of esca differ among grapevine-growing areas worldwide. South African vineyards are unique in having a minimum of ten different basidiomycete taxa from five different genera associated with the esca complex. In general, Hymenochaetales species are associated with white rot on woody plants and there are several species that are economically important to the agricultural and forestry industries. Few Hymenochaetales species have been described from the African continent, though this review is an indication of the previously unknown diversity of these fungi in Southern Africa.