Fungal agents and pathogenicity in tomatoes in Van Lake basin

This study was conducted to isolation and identification of fungi from the roots of tomato plants in Van Lake Basin in 2014. Pathogenicity experiment was established with isolates belonging to genus which are most frequently isolated in isolations. Sclerotinia spp., Alternaria spp., Macrophomina spp., Rhizoctonia spp., Fusarium spp., Phytophthora spp., Aspergillus spp., Trichoderma spp., fungi were isolated from diseased plants collected from Edremit, Gevaş, Tatvan and Erciş districts. Twenty five isolates of Sclerotinia spp. were obtained from roots of tomatoes, 22 of which were identified as Sclerotinia sclerotiorum and 3 as Sclerotinia minor. At the same time, mycelial compatible groups (MCG) of Sclerotinia isolates were identified. According to this, it was determined that there were 4 different MCGs in the S. sclerotiorum population and no discordance between S. minor isolates. The pathogenicity experiment was established by using Toprak and Alsancak tomato varieties, which are the most cultivated in the region with the obtained Sclerotinia spp. isolates. According to the pathogenicity results, the most destructive isolates of S. sclerotiorum isolates were S1, S2, S17 and S25 isolates in S. minor. S23 (S. minor) in the Alsancak (RNF1) variety and S25 (S. minor) in the Toprak (F1) variety were identified as the most destructive isolates. Among these two species S. minor was identified as virulant than S. sclerotiorum. The Alsancak variety is found to be more sensitive to the disease than the other variety. Key words: Tomato, Mycelial compatible groups, Sclerotinia minor, Sclerotinia sclerotiorum