Taxonomy and biology of diatrypaceous fungi associated with grapevine trunk diseases in New South Wales and South Australia

Abstract

The objectives of the project were to; (i) investigate the occurrence, taxonomy and biology of diatrypaceous fungi in vineyards and other hosts in NSW, (ii) study the pathogenicity of these fungi towards Vitis Vinifera and (iii) to disseminate the research findings to the industry and other researchers.

Summary

Grapevine trunk disease such as Eutypa dieback, Petri disease and Botryosphaeria canker have been well documented in Australian vineyards. However, the role of other fungi often isolated during surveys and belonging to the family Diatrypaceae remains unknown. In 2008, Dr Florent Trouillas (University of Calinoria, Davies) visited researchers at SARDI and the NWGIC to conduct a preliminary assessment of the Diatrypaceae in Australia. To continue the study further a collaborative project was established between Dr Florent Trouillas and Dr Doug Gubler (University of California, Davis) and researchers at the NWGIC, SARDI and The University of Adelaide.

A number of vineyard surveys were conducted throughout NSW and SA and previously established pathogenicity trails were assessed from SA. Over 100 specimens were analysed resulting in the discovery of many Diatrypacae fungi from grapevines with canker diseases.  Morphological and molecular techniques are being used to identify each organism to species level. In addition, Diatrypaceae were also isolated from hosts (Citris, Fraxinus, Populus and Ficus etc.) other than grapevine and in the vicinity of vineyards suggesting that these fungi have the potential to spread from other hosts into grapevines. Results from the pathogenicity trials in SA revealed that Cryptovalsa ampelina, Eutypa leptoplaca and Eutypella spp. were capable of colonising glasshouse-grown Cabernet Sauvignon grapevines and causing vascular discolorations similar to those observed in the field. These results show that the Diatrypaceae may also be contributing to the grapevine trunk disease syndrome and that these should be considered when adopting management strategies. Consideration should also be given to other host plants in the vicinity of vineyards and their potential role in harbouring these pathogens. To our knowledge, this is the first study to characterise species of Diatrypaceae associated with Vitris Vinifera and other host plants in Australia.