Multiple fungicide resistance of Botrytis cinerea from grapevine to three fungicides

【Objective】 A total of 109 single conidial isolates of Botrytis cinerea collected from vineyards in 14 regions were detected and characterized for multiple fungicide resistance to benzimidazole(carbendazim),dicarboximides(procymidone) and N-phenylcarbamate(diethofencarb).【Method】 The minimal inhibitory concentration(MIC) test was used to determine the multiple fungicide resistance of B.cinerea to the three fungicides.【Result】 The isolates showed different resistance to all the three fungicides,with a high frequency of 83.5% to carbendazim(Ben R),and low frequencies of 14.7% to procymidone(DicsR) and 17.4% to diethofencarb(NPC R),respectively.Also,fungicide resistance varied clearly between regions.Among all,100% resistance to carbendazim was observed in eight regions including Gansu,Henan,Tianjin,Jiangsu,Hebei,Hubei,Ningxia and Guangxi,whereas the resistance to procymidone and diethofencarb was restricted to few regions.The resistance types included BenRDicSNPCS,BenRDicRNPCS,BenRDicRNPCR and BenSDicSNPCR,whose percentages were as follows: 68.8%,13.8%,0.9% and 16.5%.【Conclusion】 The findings demonstrated that the multiple fungicide resistance of grapevine-infecting B.cinerea to benzimidazole(carbendazim),dicarboximides(procymidone) and N-phenylcarbamate(diethofencarb) was commonly present in vineyards of different regions in China,and the resistance to benzimidazole(carbendazim) was the most severe among all.It suggested that novel fungicides or biofungicides should be introduced for the control of B.cinerea.