新疆白车轴草白粉病病原鉴定

目的]对新疆阿拉尔地区白车轴草(Trifolium repens)上发生的白粉病进行病原鉴定.方法]通过观察测量和查阅相关文献进行病原菌形态学鉴定以及分子生物学鉴定.结果]根据形态观察,附着胞裂瓣形,分生孢子梗直立,无分支,脚胞柱形,直或稍弯曲,上接1～2个细胞,分生孢子单生呈桶-柱形,分生孢子顶端萌发.未发现有性型.病原菌核糖体DNA转录间隔区(ITS)序列与来自Genbank中的8条Erysiphe trifolii序列聚为一支,亲缘关系最紧密,且同源性达到99;.结论]采自阿拉尔地区白车轴草上的白粉菌为E.trifolii.

Identification of the Pathogen Causing Powdery Mildew of Trifolium repens in Xinjiang

Objective and Method]A powdery mildew fungus was found on Trifolium repens in Alar in Xinjiang,and the pathogen was identified by morphological and molecular methods.Result]Based on morphological observation that the appressoria were slightly lobed to multilobed,and conidia were ellipsoid or doliform type,formed singly.Conidiophore was unbranched and straight erected.Foot cell was cylindric, sometimes slightly bending followed by 1 or 2 cells.The conidia germinated from apex.Teleomorph was not collected.Furthermore,the internal transcribed spacer(ITS) sequence was together with 8 sequences from E.trifolii in GenBank and had close genetic relationship,and the identity was 99%with E.trifolii. Conclusion]The results showed that the pathogen of Trifolium repens powdery mildew in Alar belonged to E. trifolii.