Location: Crops Pathology and Genetics ResearchTitle: Wood-rotting basidiomycetes associated with grapevine trunk diseases in Texas
|BROWN, ALBRE - Texas A&M University|
|APPEL, DAVID - Texas A&M University|
Submitted to: Mycological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2016
Publication Date: 8/1/2016
Citation: Brown, A., Lawrence, D.P., Baumgartner, K., Appel, D. 2016. Wood-rotting basidiomycetes associated with grapevine trunk diseases in Texas. Mycological Society of America Abstracts. #37. ipmb.berkeley.edu/sites/default/files/MSA%202016%20abstracts%20and%20index.pdf.
Technical Abstract: Grapevine trunk diseases Esca, Botryosphaeria dieback, Eutypa dieback, and Phomopsis dieback impact vineyards in all major grape-growing regions of the world. The causal pathogens (Phaeomoniella chlamydospora and Phaeoacremonium minimum, Neofusicoccum parvum, Eutypa lata, and Diaporthe ampelina, respectively) represent five separate orders, spanning three classes of ascomycetes. They cause localized, internal infections after entering the vine wood via pruning wounds. Typically, multiple pathogens infect a single vine and sometimes even a single wood lesion. Infection by wood-rotting basidiomycetes, causing large decay columns, are thought to follow infection by the ascomycetes, although the interactive effects of such mixed infections on expression of trunk-disease symptoms has not been verified. Past reports of basidiomycetes in Esca-symptomatic vines in Australia, Europe, New Zealand, South Africa, and South America identified species of Fomitiporia, Inonotus, Phellinus, Stereum, Auricularia, and Trametes. There are only two reports of basidiomycetes causing Esca-associated white rot in North America. Our survey of 14 Texas vineyards in 2014-2016 revealed in 9 vineyards the presence of three genera of white-rot fungi: Tropicoporus, Inonotus, and Stereum. Of the 160 diseased vines that we sampled, 146 had wood or leaf symptoms of Esca, whereas the remaining vines were affected solely by one or more of the dieback-type trunk diseases (namely Botryosphaeria dieback). Retraining a symptomatic vine from the base of the trunk can restore yields to vines affected by dieback-type trunk diseases. When vine retraining was applied to Texas vineyards where Esca was confirmed, it resulted in 100% disease incidence, suggesting that infections were present in the rootstock prior to retraining.