摘要： 通过显微观察和核糖体DNA转录间隔区(ITS)序列分析对引起乌鲁木齐地区三角荨麻白粉病的病原进行了鉴定。病原菌的分生孢子梗顶端产生一个椭圆形的分生孢子,分生孢子(18.75~23.75)μm×(31.25~43.75)μm;黑褐色、球形的闭囊壳嵌在叶表面的菌丝体中,直径为87.5~143.75 μm;每个闭囊壳中有6或8个子囊,子囊无柄,大小为(25~43.75)μm×(37.5~68.75)μm,每个子囊中有4或5个子囊孢子,每个子囊孢子(18.75~21.88)μm× (25~31.25)μm。采用真菌ITS通用引物,扩增病菌rDNA ITS,测序及进化分析后发现,其ITS序列与伊朗异株荨麻白粉病菌(登录号AB104524)的同源性为99%,而且聚在一个进化支上。结果表明,乌鲁木齐三角荨麻白粉病菌属于 Erysiphe urticae,与伊朗异株荨麻白粉病菌亲缘关系最近。

关键词: 三角荨麻, 白粉病菌, 鉴定, 进化分析

Abstract: The causal pathogen of powdery mildew on Urtica triangularis in Urumchi city of China was identified by microscopic observation and molecular method.Conidiophores were cylindrical and produced one conidium at the end of the conidiophore.Conidia were ellipsoid to barrel-shaped,measured 18.75 to 23.75×31.25 to 43.75 μm.Dark brown chasmothecia were found partly embedded in the mycelial felt on leaves,were plat spherical,gregarious to scattered,and 87.5 to 143.75 μm in diameter.Each chasmothecium contained six or eight asci.Asci were sessile,25 to 43.75×37.5 to 68.75 μm,and contained four or five ascospores,each 18.75 to 21.88×25 to 31.25 μm.To further confirm identity of the causal fungus,the internal transcribed spacer (ITS) of fungal rDNA was amplified with universal primers ITS1 and ITS2,and sequenced.The ITS sequence shows 99% similarity with that of Erysiphe urticae on U.dioica from Iranian (Accession No.AB104524).The results showed that powdery mildew fungus on U.triangularis in Urumchi belonged to E.urticae,and had the closest genetic relationship with powdery mildew fungus on U.fissa from Iranian.

Key words: Urtica triangularis, Erysiphe urticae, Identification, Phylogenic analysis

中图分类号: 

• S435.63