中国和美国大豆疫霉群体遗传结构的ISSR分析

为探究中国和美国大豆疫霉的遗传关系, 采用简单序列重复区间扩增多态性(ISSR)技术, 对来自中国黑龙江省、福建省和美国的3个大豆疫霉地理群体的遗传多样性进行了分析。通过13个ISSR引物对供试的111株大豆疫霉菌株进行扩增, 共得到102个ISSR条带, 其中多态性条带为88个, 占86%。遗传变异分析表明, 美国群体具有更高的遗传变异度; Nei’s 遗传相似性和主成分分析均显示, 中国福建群体与美国群体间的遗传相似性最高, 而福建群体与黑龙江群体间遗传相似性最低; 聚类分析显示, 供试菌株在88%的相似性水平上可区分为7个聚类组, 且美国群体分布于更多的聚类组中; Shannon-Wiener多样性指数也表明美国群体的遗传多样性最为丰富。综合分析表明, 本研究的结果不支持关于美国的大豆疫霉可能来源于中国的推测。

Genetic relationships among Chinese and American isolates of Phytophthora sojae by ISSR markers

The genetic diversity of three geographic populations of Phytophthora sojae from China and the United States was determined using technique of inter-simple sequence repeat(ISSR).A total of 102 repro-ducible ISSR fragments were scored among 111 individuals,of which 88(86%) were polymorphic.Analysis of genetic variation showed that there existed higher genetic variation in the United States population in comparison to the Chinese populations.Nei's genetic identity and principal component analysis indicated that the populations of Fujian and the United States are closer to each other than to Heilongjiang populations.Shannon-Wiener diversity index revealed that the United States populations have a higher genetic diversity than that of the Chinese populations.These data support the hypothesis that P.sojae in the United States might not have been introduced from China.