【摘要】 为准确鉴定水稻立枯病的致病菌，并确定其在植物病原真菌中的分类地位，通过显微观察和基于DNA内转录间区(rDNA ITS)保守序列的分析，鉴定了分离到的水稻立枯病菌，明确了其序列与同属近缘菌的差异和在植物病原真菌中的分类地位。将分离培养的水稻立枯病菌鉴定为禾谷镰刀菌Fusarium graminearum。水稻立枯病菌F. graminearum与同属近缘种拟枝孢镰刀菌F. sporotrichioides的rDNA ITS保守区序列在92、129、150、390、394～397、399、401、403、405、408和418～419等位置存在差异。系统发育结果表明：水稻立枯病菌菌株JXNC-1与GenBank数据库中的禾谷镰刀菌F.graminearum各菌株聚为独立一支，与拟枝孢镰刀菌F.sporotrichioides亲缘关系较近。6属真菌划分为2个大的组群，Group I(G I)又细化成2个亚群。更多还原

【Abstract】 To accurately identify pathogen of rice seedling blight and make its taxonomic status clear, the identification was carried out using morphology examination and net BLAST based on rDNA ITS sequences,the differences on rDNA ITS sequences of the rice seedling blight fungus and its related fungi from the same genus were compared, and the phylogenetic analysis was carried out. The result revealed that the pathogen of rice seedling blight was Fusarium graminearum. The differences of bases were at the sites of 92, 129, 150, 390,394-397, 399, 401, 403, 405, 408 and 418-419 regions of rDNA ITS sequences on the pathogen of rice seedling blight and F. sporotrichioides, which was its nearer fungi from the same genus. The results of phylogenetic analysis revealed that rice seedling blight fungus clustered with F. graminearumand, and kept a nearer phylogenetic relationship with F. sporotrichioides. Fungi from the 6 genera clustered as 2 groups, and Fusarium had the nearest phylogenetic relationship with Trichoderma.更多还原