Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2008
Publication Date: June 1, 2008
Citation: Chen, W., Porter, L., Johnson, D. 2008. Genetic diversity of Sclerotinia sclerotiorum from various crops from the U.S. Pacific Northwest. Phytopathology. 98: S35. Technical Abstract: Sclerotinia sclerotiorum causes white mold on many crops resulting in significant economical losses. Despite extensive studies on population variation of this pathogen in many crops, the populations of S. sclerotiorum in the U. S. Pacific Northwest (PNW) have not been extensively studied. The PNW harbors diverse cropping systems including irrigated and dry land agriculture on various geographical terrains with generally mild winter conditions. The different agricultural practices and cropping sytems may impact population structure of S. sclerotiorum. This study was to examine genetic variation and population structure of S. sclerotiorum from different cropping sytems in the PNW. Mycelial compatibility groups was used to measure genetic diversity of 88 sclerotial isolates of S. sclerotiorum from three states (22 isolates from a potato field in Bonners Ferry, ID; 32 isolates from a potato field in Hermiston, OR; and 34 isolates from a pea field in Walla Walla, WA), to compare with isolate previously obtained from lentil. Each isolate was obtained at least 1.8 m away from other isolates collected witin a field. All isolates from the same field were paired in all possible combinations. High levels of MCG diversity were found among the populations: 12 MCGs were found among 22 isolates from Bonners Ferry, ID, 20 MCGs among 32 isolates from Hermiston, OR, and 23 MCGs among 34 isolates from Walla Walla, WA. Relationsip of genetic variation in neutral marker loci and variation in the quantitative phenotypic traits, pathogenicity and fungicide sensitivity, of the same populations is being investigated.