| Sclerolinia sclerotiorum (Lib.) de Bary is one of the most important rape diseases. In this study, carbendazim resistance status of S. sclerotiorum in Sichuan, Qinghai, Hunan, Gansu, Jiangsu and Anhui Province was determined. Resistance mechanism and controlling fungicides was also studied. The main results were as follows:1. The resistance detecting of S. sclerotiorum to carbendazimThe sensitivity of S. sclerotiorum from Sichuan, Qinghai, Hunan, Gansu, Jiangsu and Anhui Province to carbendazim was determined by the method of minimum inhibition concentration (MIC). The proportions of the Sichuan, Qinghai, Hunan, Gansu, Jiangsu and Anhui isolates growing halo in the plate containing 1000μg/mL carbendazim were 51.24%,51.88%,29.36%,73.43%,50% and 41.05%, respectively.No carbendazim-resistant isolate (EC50>1000μg/mL) was detected from Sichuan, Qinghai, Hunan and Gansu Province and EC50 values were in the range of 0.02-0.41μg/mL. Percents of carbendazim-resistant isolates were 35.71% and 18.18% for Jiangsu and Anhui Province, respectively.2. The characteristic of carbendazim-resistant isolates and molecular resistance mechanism of S. sclerotiorum to carbendazimActivity for producing oxalic acid and infection to rape leaves and the sensitivity to temperature of carbendazim-resistant and sensitive isolates had no significant difference.Comparing sequence of theβ-tubulin gene of carbendazim-resistant isolates with sensitive isolates of S. sclerotiorum indicated that a single mutation resulting in the replacement of GAG (Glu) by GCG (Ala) at the codon 198(E198A) caused the high resistance to carbendazim.3. Screening mixture of the fungicides to control S. sclerotiorumThe EC50 of diethofencarb and triadimefon to S. sclerotiorum were 0.0492 and 12.1987μg/mL, respectively.The Co-toxicity Coefficients (CTC) of mixture of azoxystrobin and iprodione (1:1) was 272. The CTC of mixture of triadimefon and dimethachlon (10.8:0.12,8.4:0.63) were 146 and 143, respectively. |
PDF Full Text Request