江苏省油菜菌核病菌对多菌灵的敏感性

Sensitivity of Sclerotinia sclerotiorum isolates to carbendazim in Jiangsu province

为监测目前油菜菌核病菌对多菌灵抗性现状,对从江苏省各地采集的油菜菌核病病原菌菌株以及海安、苏州和高淳三地的油菜菌核病病原菌田间群体菌株进行了多菌灵的敏感性测定。结果表明,江苏省油菜菌核病菌对多菌灵的抗药性已经产生,不同地区菌株对多菌灵的抗性比率不同。在苏州的田间菌株群体中抗性菌株的比率达到28.12%,而在高淳等地的菌株中没有检测到抗性菌株的存在。抗性菌株都表现为高抗,其EC50>100μg/mL。抗性菌株的β-微管蛋白基因进行PCR扩增和酶切的结果表明,所有抗性菌株的β-微管蛋白基因的198位都发生突变,从而导致油菜菌核病菌对多菌灵抗性的产生。从江苏省范围来看,继续使用多菌灵防治油菜菌核病可能会导致油菜菌核病菌抗性频率上升、抗性范围扩大。

Stem rot caused by Sclerotinia sclerotiorum is a devastating disease of rapeseed in Jiangsu province. The fungicide Carbendazim has been used in controlling S. sclerotiorum since 1970s. For monitoring the resistance of S. sclerotiorum to Carbendazim （MBC） at present, the sensitivity of S. sclerotiorum isolates collected from different regions and three field populations of S. sclerotiorum from Suzhou, Hai＇an and Gaochun to MBC was examined. The results showed that the ratio of isolates resistant to MBC was 11.57% within 150 isolates. The resistance level of these isolates was high. EC50 values of resistant isolates were higher than 100μg/mL. The ratios of isolates resistant to MBC were different among regions in Jiangsu. The ratio of resistant isolates reached 28.12% in the Suzhou population of S. sclerotiorum, but no resistant isolate was found in Gaochun. The β - tubulin gene from resistant isolates was PCR amplified and Thai restricted. The result showed that a point mutation at amino acid 198 of β - tubulin gene encoded protein was detected in all resistant isolate, and results in occurrence of resistance to MBC for S. sclerotiorum.