Isolation and Purification of Cotton Verticillium Wilt Pathogen and the Bioassay of wilting Phytotoxin

The wilting toxin was separated and purified from Czapck's medium liquid of cotton vcrlicillium wilt pathogen by ultrafiltration and Con.A-Scpharosc 4B affinity labeling. The component analysis and the results from bioassay of wilting phytotoxin showed that toxin was a kind of glyco-protein with a strong wilting ability, which contains 14.74% of carbonhydratc and 85.26% of protein .The toxin wilting activity was 12-15 times higher than that of half crude toxin , and the retraction wilting activity was 76%.