【作者】 段廷玉；

【导师】 王生荣；

【作者基本信息】 甘肃农业大学 ， 植物病理学， 2002， 硕士

【摘要】 调查研究结果表明：甘肃省白粉菌种类繁多，寄主广泛，在全省各地区均普遍发生，通过对采集的180多份标本初步的整理和鉴定，发现产生有性型的白粉菌分布在39科96个属133个种和变种植物上，其中有20个为白粉菌新寄主植物，8种在国内尚属首次报道。本文鉴定到种的白粉菌有39个种和变种，它们隶属于白粉科的5个属。在这39个种中甘肃新记录种2个。甘肃新记录种分别为：荆芥子白粉菌Erysiphe galeopsidis、沙参白粉菌Erysiphe adernophorae黄芪白粉病在田间的分布，在病株率60％以下时，呈聚集分布；随着病株率的增加，可能出现其它分布类型。为了提高调查的准确性，应采用“Z”字取样法或其它多点取样法进行田间调查。 各地区白粉菌种群生态分布调查结果表明：白粉菌在各区普遍发生，其多样性与植被种类的多样性直接相关，环境湿度对病害严重度有较大影响，发病寄主多呈均匀分布或团块状分布。更多还原

【Abstract】 The results of the preliminary studies showed: the powdery mildews fungi were widespread and common in all parts of Gansu province, more than 180 collections have been studied in which teleomorphic taxa have been described, 39 species belonging to 5 genera parasited on 133 host plants are known. All the collections were studied very critically with the help of upto date literature and the genera and species were confirmed according to the key provided by Zheng Ruyong et. al.(1987) and Braun U.. In the listed species two Species first reported in Gansu province were listed as follows: Erysiphe galeopsidis and Erysiphe ademophorae .The powdery mildews’ ecological distribution of different areas showed: this kind pathogens were common at Gansu Province. Diversity of the host plants affected Erysiphales diversity directly, it also has a close relations with relative humidity (RH) of the environmentMost infected host plants had a well-distribution or distributed as patches.The population diffusion index and other indices of aggregations were determined in the study of spatial pattern of Engelhardtia roxburghiana Wall, powdery mildew . T he results showed that all indices were of an aggregation pattern when disease incidence were below 60%.On the bases of the results a method of sampling-double cross lineis suggested and the sample number may be between 1700-2000.更多还原