Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2008
Publication Date: April 1, 2009
Citation: Wanner, L.A., Haynes, K.G. 2009. Regional variation in pathogenic Streptomyces species has implications for common scab resistance breeding. Meeting Abstract. American Journal of Potato Research 86:161 Technical Abstract: Common scab, caused by several species of Streptomyces, is a serious problem for potato growers. Regional patterns in the distribution of pathogenic Streptomyces species have recently begun to emerge. Although the mechanism of pathogenicity, based on the phytotoxin thaxtomin, is presumably conserved among all pathogenic species, variation in aggressiveness of different isolates is well-known. To clarify the contribution of different CS-causing species and strains of Streptomyces to local differences in CS severity in the northern USA, four contrasting potato cultivars were phenotyped in response to 13 Streptomyces isolates from different geographic regions. The isolates belong to four species and several strains. Isolates differed significantly in aggressiveness on at least one cultivar. The sum of all main and interaction effects among plant, pathogen, and environment accounted for only about half of the total variation in common scab phenotypes. After unexplained variation, host x pathogen x environment and host x pathogen were the largest sources of variation. Further information on prevalence of CS-causing species combined with knowledge of specific host-pathogen interactions could be useful in recommending suitable potato cultivars for specific growing regions. Germplasm evaluation in multiple environments with multiple strains/isolates of Streptomyces will be necessary to identify durable resistance. (Talk, Plant protection or plant breeding, PAA membership 657).