Diversity of Botrytis cinerea in major grape production regions of Hubei Province

【Objective】To assess the diversity of Botrytis cinerea in major grape production regions of Hubei Province,so as to provide scientific support for grape gray mold control.【Method】Isolates of B. cinerea from 8 main grape production regions in Hubei Province were isolated by conventional microbial separation method. All the isolates were cultured on PDA medium to observe the morphological characteristics and measure the mycelium growth rates. Transposon segments Flipper and Boty were amplified using specific primers to detect the transposon types. Bc-hch gene was amplified and detected by Hha I digestion to identify the group. Four representative isolates were used for pathogenicity analysis by inoculating on fruits of 4 grape varieties.【Result】Totally,51 isolate were obtained.Resultsof the morphological analysis showed that:Among them,30 isolates were the sclerotia type with the frequency of 58.82%,which was the most prevalent type;twenty isolates were the conidial type with the frequency of 39.22%;only 1 isolate was the mycelium type with the frequency of 1.96%. Mycelium growth rates of all isolates were high and ranged from 10.86 mm/d to 13.94 mm/d.Only two transposon types were found in isolates:50 were Transposa and only 1 was Flipper. All the isolates were classified into group II according to the restriction polymorphism analysis of enzyme Hha I of Bc-hch gene. Pathogencity analysis revealed that,isolate WH3 which had the lowest mycelium growth rate had the strongest pathogenicity. SX1,the only Flipper type isolate,had the second strongest pathogenicity. Pathogenicity of XN2 which had the highest growth rate and WH6 which was the only mycelium type were weaker. Pathogenicity regulations of isolates on different varieties were different.【Conclusion】Morphological characteristics of B. cinerea in the major grape production regions of Hubei Province is abundant. All the isolates are identified as B. cinerea in a narrow sense. There are two genotypes of transposable elements:Transposa and Flipper types. The Transposa type is predominant. The differentiation of pathogenicity is obvious between representative isolates.