北方棉区棉花黄萎病菌落叶型菌系鉴定

IDENTIFICATION OF DEFOLIATING STRAINS OF Verticillium dahliae FROM COTTON IN NORTH CHINA

采用ＲＡＰＤ 扩增与温室致病性测定２ 种方法，以黄萎病菌Ｖｅｒｔｉｃｉｌｌｉｕｍ ｄａｈｌｉａｅ 的５ 个落叶型、７ 个非落叶型菌系和Ｖ．ａｌｂｏ － ａｔｒｕｍ 的２ 个菌系为对照，对采自北方棉区６ 省（ 自治区） 的３４ 个棉花黄萎病菌菌系进行致病型鉴定。９４ ．１ ％ 的菌系在２ 种鉴定结果中表现一致，与对照菌系相比较，确定其中２６ 个菌系为落叶型菌系，６ 个菌系为非落叶型菌系。从而证实了黄萎病菌落叶型菌系在北方棉区河北、河南、山东３ 省的存在，并发现所确定的２６ 个北方落叶型菌系中的２２ 个与来自美国的对照落叶型菌系Ｔ９ 、Ｖ４４ 的关系比与来自江苏的对照落叶型菌系ＶＢ、Ｖ９９１ 的关系更近。本实验还初步筛选到２ 条用于鉴别Ｖ．ｄａｈｌｉａｅ 落叶型与非落叶型菌系的ＲＡＰＤ 特异条带ＯＰＢ－ １９９６６ 和ＯＰＭ－ ２０１６９１ ，将它们用于对３４ 个北方菌系的ＲＡＰＤ 扩增鉴定，则与温室致病性测定结果的一致性分别为８８ ．２ ％ 和９４ ．１ ％ ，证明这２ 条特异条带在鉴定棉花黄萎病菌落叶型菌系上具有一定的实用价值，并为进一步制作特异探针以形成一套简便、准确。

Strains of Verticillium ,including 5 defoliating and 7 nondefoliating strains of V.dahliae and 2 strains of V.albo-atrum, were used as check in the present experiment in which random amplified polymorphic DNA and pathogenicity identification were performed with 34 strains of V.dahliae from cotton in 6 provinces and autonomous regions of North China. The results showed that 94.1% strains, including 26 defoliating and 6 nondefoliating strains, were identical. So the defoliating strains were confirmed to exist in cotton growing areas of Hebei, Henan and Shandong Provinces. The relationship between 22 northern defoliating strains and control defoliating strains from America T 9, V 44 was found to be closer than from Jiangsu Province V B, V 991 . At the same time, two specific RAPD bands were found only from defolia ting strains,named OPB-19 966 and OPM-20 1691 . With the primer OPB-19 and OPM-20,RAPD was conductd on 34 strains of V.dahliae from cotton in North China and the identity between the results from the two specific bands and from the pathogenicity identification were 88.2% and 94.1% respectively. The two testified specific RAPD bands might have some practical value for differentiation.