Location: Crops Pathology and Genetics ResearchTitle: Comparisons of fungal trunk pathogens and endophytic fungi between minimally-pruned and spur-pruned vines in southern France
|Travadon, Renaud - University Of California|
|Lecomte, Pascal - Institut National De La Recherche Agronomique (INRA)|
|Diarra, Barca - Institut National De La Recherche Agronomique (INRA)|
|Lawrence, Daniel - University Of California|
|Vallance, Jessica - Bordeaux Agro Sciences|
|Oreda, Hector - Institut National De La Recherche Agronomique (INRA)|
|Rey, Patrice - Bordeaux Agro Sciences|
Submitted to: Group of International Experts of Vitivinicultural Systems for CoOperation(GiESCO)
Publication Type: Abstract Only
Publication Acceptance Date: 6/11/2015
Publication Date: 6/11/2015
Citation: Travadon, R., Lecomte, P., Diarra, B., Lawrence, D.P., Vallance, J., Oreda, H., Rey, P., Baumgartner, K. 2015. Comparisons of fungal trunk pathogens and endophytic fungi between minimally-pruned and spur-pruned vines in southern France. Group of International Experts of Vitivinicultural Systems for CoOperation(GiESCO). 19th Group of International Experts of Vitivinicultural Systems for CoOperation, December 15, 2014.
Technical Abstract: The main infection courts for grapevine trunk pathogens are thought to be pruning wounds. As such, we expect pruning practices that require fewer/smaller wounds to be associated with fewer pruning-wound infections. In turn, minimal pruning may lead to less wood necroses and a lower diversity of trunk pathogens. To test this hypothesis, we characterized the trunk pathogen communities of 14-year-old vines (Mourvèdre and Syrah), which were either spur-pruned or minimally pruned, at INRA Pech-Rouge experimental station in southern France. The trunks of eight minimally-pruned and eight spur-pruned vines per cultivar were visually examined for proportions of necrotic wood (in longitudinal section) and fungi were cultured from 64 wood pieces per vine. A total of 90 fungal taxa were identified by ITS-DNA sequencing of representative isolates, including 29 taxa of known or putative trunk pathogens. Among the 32 vines, the most prevalent trunk pathogens were Diplodia seriata (81% of vines), Phaemoniella chlamydospora (66%), Togninia minima (47%), Neofusicoccum parvum (34%), Diaporthe neotheicola (25%), Phomopsis viticola (19%), N. australe (13%), Eutypa lata (9%) and N. luteum (9%). Canonical Correspondence Analysis (CCA) of the most common fungi, revealed that wood type had a more significant effect on relative abundance than did pruning. We found significantly higher relative abundances of D. neotheicola, T. minima, P. chlamydospora, and N. parvum in heartwood, compared to sapwood. Spur-pruned vines had significantly higher proportions of necrotic wood (35%) than minimally-pruned vines (20%). Minimally-pruned vines supported greater populations of N. parvum and P. chlamydospora, suggesting that planting material was pre-infected, or that natural wounds in the trunk are alternative infection courts.