Sensitivity baseline and cross-resistance of Sclerotinia sclerotiorum to iprodione and dimethachlon
The sensitivities of 50 isolates of Sclerotinia sclerotiorum,the causal organism of rapeseed stem rot,isolated from Fengyang,Xuancheng,Wangjiang,Feixi,Jingde,Taihu,Hefei,Mengcheng,Lingbi and Chaohu in Anhui Province to iprodione and dimethachlon were tested in vitro.The results showed that the EC50 values of iprodione to all tested strains ranged from 0.0962 to 0.4381 mg·L-1 with the average of 0.2176 mg·L-1 and that of dimethachlon ranged from 0.0527 to 2.2365 mg·L-1 with the average of 1.0227 mg·L-1.It suggested that the tested isolates from the 10 localities were still sensitive to iprodione and dimethachlon,but the sensitive level from all localities showed obvious difference.Correlation analysis of the EC50 level of the tested isolates displayed that no cross-resistance existed between iprodione and dimethachlon to S.sclerotiorum.