云南地区铁线莲叶枯病病原菌的鉴定和主要生物学特性

Identification and main biological characteristics of pathogen of Clematis leaf blight in Yunnan

为明确引起云南省铁线莲叶枯病病原菌的种类,从患叶枯病的植株上采集病叶,采用常规组织分离法进行病原菌的分离纯化,通过观察病原菌的形态学特征,结合核糖体内转录间隔区(ITS)和大亚基(LSU)双基因序列分析对病原菌的种类进行鉴定,采用科赫法则进行验证。并用不同培养基、温度、光照、pH、碳源和氮源对病原菌的主要生物学特性进行了测定。结果表明:铁线莲叶枯病的致病菌为Spencermartinsia sp.,按照科赫法则接种植株的叶片均发病。马铃薯葡萄糖琼脂培养基(PDA)和马铃薯蔗糖琼脂培养基(PSA)为其适宜培养基,生长最适温度为25℃,不同光照处理下生长不受影响,生长最适pH为6.5~7.5,最佳碳源为葡萄糖和蔗糖,最佳氮源为硝酸钠。

In order to identify the pathogen of Clematis leaf blight in Yunnan Province,the typical diseased leaves were collected from the diseased plants.The pathogen was isolated and purified by tissue separation method,and identified by morphological characteristics combined with sequence analysis of ribosomal internal transcribed spacer(ITS)and large subunit(LSU),and verified by Koch postulates.The main biological characteristics of the pathogen were determined with different media,temperature,light,pH,carbon and nitrogen sources.The results showed that the pathogen of Clematis leaf blight was Spencermartinia sp.,according to Koch postulates,all the leaves inoculated with the pathogen were infected.Potato dextrose agar(PDA)and potato saccharose agar(PSA)were the suitable media,the optimum temperature for growth was 25℃,the growth was not affected under different light treatments,the optimum pH for growth was 6.5-7.5,the best carbon source was glucose and sucrose,and the best nitrogen source was sodium nitrate.