对从甘肃省渭源县采集到的黄芪根腐病病株进行了病原菌的分离、纯化和致病性检测，并对致病菌形态学进行了观察，结合核糖体DNA(rDNA) ITS序列分析的分子生物学鉴定，以明确引起黄芪根腐病的致病病原菌。结果表明:黄芪根腐病致病菌为半知菌亚门(Deuteromycotina)丝孢纲(Hyphomycetes)瘤座孢目(Tuberculariales)瘤座孢科(Tuberculariaceae)镰刀菌属(Fusarium)的4个种。共分离出16个菌株，经检测有5个菌株具有致病性，均属镰刀菌，其中尖孢镰刀菌(Fusarium oxysporun)1株(9号菌株)，腐皮镰刀菌(Fusarium solani)2种(12号菌株和16号菌株，其中16号菌株可能为腐皮镰刀菌的变种)，锐顶镰刀菌(Fusarium acuminatum)1株(15号菌株)，待定镰刀菌1株(14号菌株，与三线镰刀菌的同源性仅为88%)。

The root rot strains of Astragalus membranaceus root rot symptom collected from Weiyuan County， Gansu Province were isolated， purified and tested for pathogenicity， and by morphological identification and identification of pathogenic bacteria with molecular identification of ribosomal DNA(rDNA) ITS sequence analysis， so as to identify pathogenic bacteria of causing Astragalus membranaceus root rot. The results show that the pathogen of root rot of astragalus membranaceus was four species of Deuteromycotina， Hyphomycetes， Tubercuariles， Tuberculariaceae， Fusarium， a total of 16 strains were isolated, and 5 strains were detected to be pathogenic， all of which were fusarium， of which 1 strain(strain 9) was Fusarium oxysporum， 2 strains of (strains 12 and strains 16 of which may be a variant of Fusarium solani) were Fusarium solani， 1 strain(strain 15) was Fusarium acuminatum， 1 strain(strain 14， only 88% homologous to Fusarium trichomonas) was determined Fusarium.

S512.1

甘肃省中青年基金项目(3YSO61-A25-030)。