我国棉花黄萎病菌的群体遗传

The Population Genetics of Cotton Verticillium Wilt in China

从 1 2 6条随机引物中筛选出 9条能产生多态性好、条带稳定的引物。用这 9条引物对来自我国主产棉区河北、河南、江苏、山东 4个群体的 9个亚群体 1 1 7个菌株进行 RAPD扩增。对各个群体、亚群体的群体遗传结构分析表明 ,各省群体遗传相似性较高 ,总的遗传变异量为 0 .0 947,其中72 .5%由群体内的变异引起 ,1 2 .5%由省内群体间引起 ,1 5%由群体间的变异引起 ;群体间的基因流动值为 2 .83 ,群体间、亚群体间均存在较高的基因流动 ;落叶型特征条带在各个亚群体内出现频率均很高 ,表明棉花黄萎病菌落叶型菌株在我国主产棉区的河北、河南、山东、江苏 4省棉区分布广泛 。

Nine primers that gave informative and consistent amplification in the analyses from 126 primers were used to amplify DNA of all 117 isolates of Verticillium dahliae from 9 subpopulations within 4 main areas in China. Genetic similarities of RAPD frequency showed that populations from four provinces are similar(0.094). Among them gene diversity was decomposed hierarchically: 72.5% of gene diversity was attributable to diversity within subpopulations, compared to 12.5% among subpopulations within province, compared to 15% among province levels of populations. There were high gene flow among populations and subpopulations and the estimate of Nm among province populations was 2.83. The high frequency of distinctive fragments for defoliating indicated the defoliating type isolates of V. dahliae have been in the main cotton areas of China North and are becoming the dominant strains.