河北省棉区黄萎病菌系基于RAPD的遗传分化研究

本研究对２３个棉花黄萎病菌系，其中１９个为河北省棉区不同致病群（ＶＧｓ）的代表性菌系，用２５个可揭示菌系遗传多态性的随机引物进行ＲＡＰＤ扩增，研究了病菌的遗传分化及与其来源和致病性的关系。结果表明，菌系间的遗传相似系数变化在０．４４２～１．０００之间，但大多数菌系间的同源程度较高。基于８９个ＲＡＰＤ标记的聚类分析表明，供试菌系被划分为２个ＲＡＰＤ群（ＲＧｓ）和８个ＲＡＰＤ亚群（ＲＳＧｓ），其中河北省棉区黄萎病菌系的遗传分化程度较小，９５％的菌系归属于同一ＲＡＰＤ群（ＲＧ１），仅１个菌系属于ＲＧ２。ＲＡＰＤ类群与病菌地理来源有一定相关性，但与病菌致病群（ＶＧｓ）相关性不大。进一步分析表明，ＲＡＰＤ亚群（ＲＳＧｓ）与ＶＧｓ间存在一定关系，其中ＲＳＧ１中的８个菌系全部为强致病力的ＶＧⅠ菌系；ＲＳＧ２中６６．７％的菌系为ＶＧⅡ菌系。ＲＧｓ和ＲＳＧｓ与菌系是否与落叶型无关。

Study on Genetic Differentiation of Verticillium dahliaeZ Isolates from Cotton Areas of Hebei Province Based on RAPD

Among RAPD amplifications to 23 XVerticillium dahliae strains, 19 representatives of different virulence groups(VGs) from Hebei Province, were performed with 25 random primers. Genetic similarity coefficients within the strains were among 0.4421.000, but there existed a high degree of homogenety between most of them showing a lower differentiation among the strains. When all polymorphic RAPD bands were used for cluster analysis using the SAS program, 23 isolates were classified into 2 RAPD groups(RGs). There was a major group, i.e. RG1, containing 18 strains from Hebei and accounting for as much as 94.74% of the total representatives. Thus, a less abundant genetic diversity was found in the population of the verticillium wilt fungus in Hebei cotton producing areas. Moreover, results showed that RAPD groups were generally associated with the geographic regions where the strains came from, but there was no relationship between the RGs and the VGs. However, RAPD sub-groups(RSGs) seemed to be relate