Effect of electron beam irradiation on pathogenicity and pathogenic enzyme activity of botrytis cinerea

In order to define the effect of electron beam irradiation on pathogenicity of Botrytis cinerea mycelia, the disease parameters of strawberry fruits inoculated with mycelia of B. cinerea irradiated by electron beam with different dose were tested in vivo, the production and activity of pectinase and cellulase secreted by B. cinerea irradiated by electron beam were also tested by DNS method. The results showed that pathogenicity of irradiated B. cinerea decreased significantly. The disease incidence and disease index of strawberry inoculated by irradiated B. cinerea after 3 days and 5 days was only 15.00% and 11.39 compared to control (91.67% and 77.78), respectively. The activity of pectinase and cellulase of B. cinerea irradiated by electron beam with above 2.0 kGy were inhibited obviously. The activity of PMG of irradiated B. cinerea decreased by 37.65% and 57.46% compared with control 3 days and 5 days cultured at 20℃, and the activity of CX and BG decreased by over 60% than that of control. The hardness of strawberry treated by enzyme solution which producted by B. cinerea irradiated by electron beam at 2.0 kGy was higher than that of control strawberry and it mainted disease resistance well. Electron beam can inhibited the pathogenic enzyme activity and pathogenicity of B. cinerea obviously. So it can control gray mold of postharvest strawberry effectively. (authors)