中文摘要：

依据病原菌分生孢子形状、大小、芽管着生位置、纤维体的有无等特征,对贵州省贵阳市、遵义市、六盘水市、安顺市4个城市市郊的12份南瓜白粉病标样进行了病原菌的初步鉴定。结果表明：引起贵州省南瓜白粉病的病原菌为苍耳单囊白粉菌（Podosphaera xanthii）,该病原菌的侵染是造成贵州瓜类蔬菜栽培上的白粉病病因。该病菌不侵染辣椒、番茄、烟草3种贵州主栽经济作物,可侵染苦瓜、黄瓜和冬瓜等瓜类蔬菜。

英文摘要：

Total 12 samples of hull-less pumpkin powdery mildew collected from Guiyang,Zunyi,Liupanshui,and Anshun in Guizhou Province were identified based on the shape of conidium,the position of germ tube,the exis tence and non-exis tence of corpus fibrosum.The results showed that pathogen was identified as Podosphaera xanthii,the pathogen on gourd vegetables was P.xanthii in Guizhou Province,the host range test showed that the pathogen could infect many species except Capsicum annuum,Lycopersicon esculentum,and Nicotiana tobacum.The pathogen could also attack Momordica charantia,Cucumis sativus,and Benincasa hispida.