MYCELIAL COMPATIBILITY GROUPS IN POPULATIONS OF SCLEROTINIA SCLEROTIORUM (LIB.) DE BARY, THE CAUSAL AGENT OF SCLEROTINIA ROT OF OILSEED CROPS IN NORTH AND NORTHWEST OF IRAN

In this study population variability of Sclerotinia sclerotiorum, the causal organism of Sclerotinia stem and stalk rot of canola and sunflower, respectively, was determined by mycelial compatibility grouping (MCG). Among 355 isolates tested, 64 MCGs were identified, and single–isolate mycelial compatibility groups, 64% and 36% were obtained from the North and NorthWest of Iran, respectively. The results showed that highly significant differences (P<0.001) were observed in growth, number of sclerotia, weight of sclerotia and aggressiveness among MCG’s of North and Northwest of Iran.