基于ISSR-PCR对山东玉米多堆柄锈菌遗传多样性的研究及其初侵染菌源的推测

利用11对多态性ISSR引物对2014-2016年间采自山东、江苏、浙江、河南及海南等5省的60个玉米多堆柄锈菌菌株进行了种群遗传多样性分析。结果表明,分离自山东的玉米多堆柄锈菌菌株的遗传多样性丰富,多态性百分率（ P）达96.34%,与江苏、浙江、河南锈菌种群具有较高的相似性,遗传距离相对较近,其中与江苏的群体遗传相似系数最高（GS=0.7829）,遗传距离最近（GD=0.2447）,而与分离自海南的锈菌种群相似性最低（GS=0.0148）,遗传距离最远（GD=4.2999）。在相似性系数0.74水平上,供试60个菌株被划为3个群和多个亚群组,各群和亚群间表现出较明显的年度与地理分布上的差异。2015年采集的菌株之间 G_st值为0.8694,2015与2016年采集的菌株群体间的 G_st值为0.4562,说明病菌的遗传变异不仅表现在地域上,也体现在年度间。基于ISSR标记分析,作者认为发生在山东省的玉米南方锈病其初侵染菌源不是来自我国周年发生玉米南方锈病的海南省,而最有可能来自同样能越冬的菲律宾或我国台湾地区。

Genetic diversity and deduction of primary infection source of Puccinia polysora in Shandong Province based on ISSR-PCR

The genetic diversity of 60 strains of Puccinia polysora collected from Shandong, Jiangsu, Zhejiang, Henan and Hainan provinces from 2014 to 2016 was analyzed by using eleven pair of polymorphic ISSR primers. The results indicated that, the genetic diversity of the strains collected from Shandong Province was abundant, and its polymorphic percentage ( P) was 96.34%. The genetic diversity of the strains was highly similar to that of the strains collected from Jiangsu, Zhejiang and Henan provinces, and the genetic distance was relatively high. The strains collected from Shandong Province showed the highest genetic similarity coefficient (GS=0.7829) and the closest genetic distance (GD=0.2447) as compared to those collected from Jiangsu Province; however, the strains from Shandong showed the lowest genetic similarity coefficient (GS=0.0148) and the farthest genetic distance (GD=4.2999) as compared to those of collected from Hainan Province. At the level of similarity coefficient 0.74, the 60 strains were classified into three groups and several subgroups, and there were obvious differences in annual and geographical distribution between the groups and subgroups. G_st value of the strains collected in 2015 was 0.8694, and that of the strains collected both in 2015 and in 2016 was 0.4562, indicating that the genetic variation of the pathogen was reflected not only in different regions, but also in different years. Based on ISSR marker analysis, the authors believed that the primary infection sources of the disease occurred in Shandong Province were not from Hainan Province, but probably from the pathogen overwintering region, such as Philippines or Taiwan.