Investigation of the variation amoung the Sclerotinia sclerotiorum population isolated from lettuce in greenhouse in Çanakkale

This research was, to determine the variation of the population of Sclerotinia sclerotiorum, which is a agent of soft rot disease in lettuce growing in greenhouse in Çanakkale, done between 2005 and 2008. Primarily, plants, which were infected, were noted and sclerot were collected by chance from infected lettuce in greenhouses. Surveys were done between January and March. The isolation of 116 isolates, obtained from lettuce, were done in in vitro and isolates were paired together in potato dextrose agar (PDA) amended with red food colour to determine mycelial compatible groups (MCG) amoung them. As a result of the growing of the colonies in PDA, pairings were scored as mycelial compatible if sclerot formed in the interaction zone, pairings were scored as mycelial incompatible if a red line and a gap occured in the interaction zone. The result of pair of isolates, 46 MUG were described. Some of the isolates were found only selfcompatible when more than two isolates placed most of MCGs. Isolates, which were in the same MCG, could be in the same greenhouses, it could be different greengouses. More than one MCG were obtained amoung isolates, were collected in same greenhouses. Furthermore, isolates were wacthed in respect of sclerot number and weight formed in PDA and the variation was determined between the isolates. Differents were determined between the isolates for MCGs and morphological characters. It was determinated, vegetative and morphologic different were being amoung isolates in S. sclerotiorum population ontained from lettuce in Çanakkale, with this study.