大白菜根肿病菌生理小种鉴定研究

为明确我国各地根肿病菌致病性的不同，分别使用Williams 鉴别系统和具有不同根肿病抗性的4 个大白菜品种对采 自全国多地的20 份大白菜根肿病菌菌源进行生理小种和致病型的划分。利用Williams 鉴别系统进行鉴定，其中18 份为4 号 生理小种，2 份为2 号生理小种。利用4 个大白菜品种进行鉴定，根据致病力不同划分为6 种类型，其中4 号生理小种存在 6 种类型，2 号生理小种存在2 种类型。认为Williams 鉴别系统已不能精确划分大白菜根肿病菌的生理小种，而研究筛选具 有不同抗病类型的大白菜品种（品系）鉴定划分根肿病菌致病型具有重要意义。

Studies on Physiological Race Identification of Plasmodiophora brassicae Woron. in Chinese Cabbage

In order to clear and definite the different pathoogenicity of clubroot from regions all over China，this paper classified the physiological races and pathotypes of clubroot in 20 Chinese cabbages collected from all over the country，using Williamms identification system and 4 Chinese cabbage varieties with different resistances to clubroot．The results of using Williamms identification system showed that 18 Chinese cabbage varieties were belonged to No.4 physilogical race，and 2 were belonged to No.2 physilogical race．The result of identifying 4 Chinese cabbage varieties showed that according to their different pathogenicities，they were divided into 6 types．There were 6 types existing in No.4 physilogical race and 2 types in No.2 physilogical race．The paper deems that the Williams identification system has not been able to precisely divide the physilogical race of Chinese cabbage clubroot pathogen，and it is of important significance to study on screening Chinese cabbage varieties（lines）with different disease resistances and identifying clubroot pathogen pathotypes．