河南省大白菜根肿病菌生理小种鉴定

为了明确河南省大白菜根肿病菌的生理小种类型,从新野县十字花科蔬菜种植基地采集2份大白菜根肿病菌样品(XY-1为原始菌,XY-2为新引菌),采用菌液注射接种法,利用Williams和ECD 2套鉴别系统分别对其进行生理小种鉴定。结果显示,采用Williams鉴别系统鉴定的2份大白菜根肿病菌生理小种相同,均为4号生理小种;采用ECD鉴别系统鉴定的大白菜根肿病菌生理小种明显不同,原始菌XY-1为ECD16/15/31,新引菌XY-2为ECD21/31/31,后者较前者的致病性更强。以上结果表明,Willams鉴别系统有一定的局限性,当病原菌致病力强于4号生理小种时无法区分,而ECD鉴别系统由于所用寄主数量及种类较多,可以将4号生理小种进一步区分为不同的类型,鉴定结果更为精确。

Pathotype Identification of Plasmodiophora brassicae Woron.Collected from Chinese Cabbage in Henan Province

In order to clarify the pathotype of Plasmodiophora brassicae Woron.on Chinese cabbage in Henan province,two isolates XY-1 and XY-2 collected from Chinese cabbage clubbed roots in Xinye county,representing original and newly introduced pathogens were identified respectively.The identification was carried out by inoculating spore suspension based on the differential sets of Williams system and ECD system.The result showed that both XY-1 and XY-2 were classified into the pathotype 4 of P.brassicae based on the Williams differential system,while based on the ECD differential system,two different pathotypes were classified with XY-1 as pathotype ECD16/15/31 and XY-2 as pathotype ECD21/31/31.The inoculating test showed that the newly introduced pathogen (XY-2) was more virulent in pathogenicity on Chinese cabbage than the original one (XY-1).The above results indicated that the ECD system was more precise than the Williams system due to lager number and more species of differential hosts used for classification,which could further divide the pathotype 4 into different types.