Abstract:In order to study the pathotype population variation of cotton Verticillium dahliae in Shangqiu of Henan Province, eight cotton V.dahliae strains from this area were analyzed on colony morphology, microscopic structure, pathogenicity, internal transcribed spacer (ITS) sequence, evolution and total fungal protein. The analysis of colony morphology, microscopic structure and ITS sequence indicated that the eight collected strains belonged to V.dahliae. Phylogenetic tree was constructed based on ITS sequences. It was shown that eight strains have different pathogenicities, SQ4 strain showed higher pathogenicity, which belonged to defoliating type, than the other 7 strains, which belonged to non-defoliating type. The SDS-PAGE analysis of total fungal proteins indicated that the strains with different pathogenicities showed different protein profiles.