|TRAVADON, RENAUD - University Of California|
|WILCOX, WAYNE - Cornell University - New York|
|ROLSHAUSEN, PHILIPPE - University Of California|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2009
Publication Date: 1/15/2010
Citation: Baumgartner, K., Travadon, R., Wilcox, W., Rolshausen, P.E. 2010. Identity of Phomopsis species recovered from wood cankers in eastern North American vineyards. Phytopathologia Mediterranea. 49:108.
Technical Abstract: Phomopsis cane and leaf spot is relatively common in eastern North American Vitis labruscana vineyards, from which P. viticola is consistently recovered from green shoot and berry lesions. Vitis vinifera vineyards, and associated training and pruning practices, are becoming more common. As such, pruning wounds accumulate on individual vines, thereby increasing the potential for infection by trunk pathogens. Fifteen Phomopsis species have been identified from grape (from green shoot lesions and wood cankers), but primarily from Mediterranean regions. In this cold-climate, to characterize the species community of Phomopsis grape pathogens, we surveyed vineyards in the northeastern US (CT, MA, MD, MI, NH, NJ, NY, OH, RI, VA, VT) and Quebec and Ontario, Canada, primarily for general symptoms of trunk disease (wood cankers), but also for typical symptoms of Phomopsis cane and leaf spot (green shoot lesions). Species-level identification of collections with morphological characteristics of Phomopsis was based on phylogenetic analyses of five nuclear loci: rDNA internal transcribed spacer region, translational elongation factor subunit 1-alpha, calmodulin, beta-tubulin, and RNA polymerase II subunit B. Individual and combined phylogenies showed that all isolates from green shoot lesions were P. viticola. A few isolates recovered from wood cankers were identified as P. viticola, but the majority were the following other species: Diaporthe phaseolorum, P. vaccinii, P. amygdali, and several unknown Phomopsis species. Therefore, Phomopsis cane and leaf spot controls may not be effective against pruning wound infection by this species complex.