周口地区油菜白粉病病原的鉴定

Identification of Erysiphe cruciferarum in Zhoukou of Henan Province

本研究通过扫描电镜观察以及分子鉴定方法,对引起河南周口地区油菜白粉病的病原进行了鉴定。结果显示:在扫描电镜下该病原菌分生孢子为椭圆或圆柱形;采用真菌核糖体DNA转录间隔区(ITS)通用引物,扩增病菌核糖体基因ITS区,并对产物进行克隆、测序及进化树分析,其ITS序列与Erysiphe cruciferarum(韩国)的ITS序列同源性为100%,而聚在一个进化枝上。上述结果表明,周口地区油菜白粉病菌属于E.cruciferarum,与韩国甘蓝型油菜白粉病菌亲缘关系最近。

The pathogen cattsing powdery mildew on Brassica oleracea in Zhoukou, Henan Province, was indenti- fled by scanning electron microscope and molecular identification. The internal transcribed spacer（ITS） region of the rDNA from Erysiphe cruciferarum was amplified with universal primers and sequenced. Meanwhile, the ITS of homologous sequences from NCBI were clustered. The scanning electron microscope（SEM） results demonstrated that the conidia were borne singly, cylindrical, or ellipsoidcylindrical. The ITS sequence is 100% homologous to that of E. cruciferarum from Korea, while phylogenetic tree demonstrated that they were clustered in one clade. The powdery mildew fungus on B. oleracea in Zhoukou belongs to E. cruciferarurn and is close to the isolate from Korea according to genetic relationship.