Abstract: The genetic diversity of 230 monoconidial isolates of Magnaporthe grisea was analyzed using eight pairs of SSR markers.All isolates tested were classified into seven genetic lineages at 0.23 level of the genetic dissimilarity through the clustering analysis of UPGMA.The lineages Ⅰ,Ⅴ,Ⅵ were the predominant ones with the rates of 23.9%,23.5%,23.0% respectively.Only one isolate fell into the lineage Ⅳ and five isolates belonged to the lineage Ⅶ.As 77 isolates selected from above monoconidial isolates were characterized with seven Chinese differential varieties,they were distributed to the 7 groups(ZA,ZB,ZC,ZD,ZE,ZF,ZG) and 30 pathotypes.There was great differentiation among ZA,ZB and ZC groups.ZG1 was the predominant race,and its frequency in the total blast fungus population was as high as 26.5%.Compared with the results of SSR analysis and pathotypes,there wasn’t obviously corresponding relationship between genetic lineages and pathotypes.

Key words: Oryza sativa, Magnaporthe grisea, simple sequence repeat, genetic diversity, pathotype

摘要： 用8对SSR引物对230个稻瘟病菌菌株进行遗传多样性分析。经UPGMA聚类分析，在相异系数为0.23水平上，供试菌株划分为7个遗传宗谱，其中Ⅰ、Ⅴ、Ⅵ宗谱为优势宗谱，所占比例分别为23.9%、23.5%和23.0%，Ⅳ和Ⅶ宗谱中分别只有1个和5个菌株，其所占比例仅为0.43%和2.17%。用7个全国统一鉴别品种对从230个菌株中选出的77个菌株进行致病型鉴定，结果表明湖南稻瘟病菌分属ZA、ZB、ZC、ZD、ZE、ZF、ZG等共7群30个致病型。其中 ZA、ZB、ZC 3个种群的分化较强，分别含6、10、7个致病型，其中ZG1为优势致病型，出现频率为26.5%。SSR标记的遗传多样性分析结果以及以不同鉴别品种表型来划分的致病型结果表明，菌株遗传宗谱与致病型不存在一一对应关系。

关键词: 水稻, 稻瘟病菌, 微卫星标记, 遗传多样性, 致病型