苹果黑星病菌致病力分化的研究

Studies on differentiation of Venturia inaequalis of apple in pathogenicity

为了明确田间苹果黑星病菌致病力的分化情况,选取中国、英国、印度3个国家不同苹果产区的57株有代表性的苹果黑星病菌株,分别接种嘎啦、富士、秦冠3个寄主品种进行致病力测定。结果表明,不同菌株在相同寄主上能产生不同类型的病斑,其病斑大小、形状、颜色存在较大差异。同一菌株对不同寄主品种的致病力也存在较大差异。根据寄主对病菌的反应类型并结合病害严重度的聚类分析结果,可将57株苹果黑星病菌菌株划分为3个类群:强致病力Ⅰ型、中等致病力Ⅱ型、弱致病力Ⅲ型。

In order to explicit the pathogenicity differentiation of Venturia Maequalis in fields, three apple cultivars were individually inoculated with 57 representative single spore isolates of Venturia inaequalis collected respectively from different apple producing areas in China, England and India. Results showed that there was obvious difference in pathogenicity among those tested isolates that could produce different types of disease spots in their size, shape and color on the same inoculation host. There was also obvious difference in pathogenicity even if different hosts were inoculated by the same spore isolates of Venturia inaequalis. Based on the host reaction and cluster analysis of disease severity, the 57 isolates of Venturia inaequalis could be divided into three categories： strong （pathotype Ⅰ） ,intermediate （pathotype Ⅱ ） and weak pathogenicity （pathotype Ⅲ） respectively.