|Jimenez-Hidalgo, I - WSU-IAREC, PROSSER,WA|
|Kohn, L - UNIV OF TORONTO|
|Chen, W - WSU-IAREC, PROSSER, WA|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: February 1, 2004
Publication Date: N/A
Technical Abstract: The population structure of Sclerotinia sclerotiorum on canola and on soybean in central Canada is part of one population of the pathogen that is mainly clonal with some local subdivision. The objective of our research is to describe the population structure of S. sclerotiorum in an intensively sampled field of pea. Fifty isolates were obtained from sclerotia collected from inside diseased stems or from plant tissue excised from the margins of stem lesions. AFLP, microsatellite markers and mycelial compatibility grouping were used to describe genotypes of the pathogen population. Two AFLP primer combinations were used and in one, 45 different fingerprints were identified, while in the other 50 fingerprints were observed. No common AFLP fingerprint patterns were detected between isolates retrieved from the WA pea field and 10 Canadian isolates derived from canola and soybean, used as reference isolates. Twenty-six different MCGs were observed and 6 of these were represented by more than one DNA fingerprint (between 2 and 6 fingerprints). Four clones based on MCGs and AFLP fingerprints were identified. Some isolates were compatible with isolates in several MCGs. Non-transitivity of MCG testing was observed in 10 cases. Using four microsatellite primer sets, 9 microsatellite profiles were identified in pea isolates and they differed from the reference isolates. The population of S. sclerotiorum in pea has a higher genotypic diversity in the Pacific Northwest than expected from previous studies.