基于SSR标记的不同地理生态型野生大豆遗传多样性分析

Genetic Diversity Analysis of Wild Soybean (Glycine soja) Populations with Different Geographical Ecotypes Based on SSR Markers

为充分了解野生大豆的遗传进化特征,促进资源保护及高效利用,本研究利用29对SSR引物对6个不同地理生态型的126份野生大豆资源进行遗传多样性和遗传结构分析。结果表明:共测到635个等位基因,平均等位基因数为21.897个,平均引物多态性信息含量为0.883,Shannon指数和预期杂合度分别为2.586和0.890。STRUCTURE遗传结构预测将6个群体分为2个类群,东北区来源的野生大豆资源与西北、黄淮海、长江流域和南方来源归属不同类群。F-统计和AMOVA分子方差分析显示,总体变异的88%发生在个体间,8%发生在群体间,并且异交率呈现由北向南逐渐增加的趋势。Mantel检测显示,遗传距离与地理距离显著相关(r=0.468,P<0.01),与生育期不相关(P>0.05)。综上,野生大豆群体的分化是自然选择和"邻近效应"共同作用的结果,异交率水平和距离隔离是野生大豆遗传结构形成的重要因素。

In order to fully understand the genetic evolution characteristics of wild soybean and promote resource conservation and efficient utilization, 29 pairs of SSR primers were used to analyze the genetic diversity and genetic structure of 126 wild soybean resources belonged to 6 different geographical ecotypes. The results showed that, 635 alleles were detected, the average number of alleles was 21.897 and the average primer polymorphism information content was 0.883. Shannon index and expected heterozygosity were 2.586 and 0.890, respectively. STRUCTURE analysis showed six populations were divided into two groups, wild soybean resources from northeast region and different lineages from northwest, Huanghuai, Yangtze and southern groups. F-statistics and AMOVA analysis of variance indicated that 88% of the total variation occurred among individuals and 8% among populations. Mantel test showed that genetic distance was significantly correlated with geographical genetic distance(r=0.468, P<0.01), but not with growth period(P>0.05). In conclusion, the differentiation of different geographical ecotypes of wild soybean is the result of natural selection and "proximity effect", and the level of outcrossing rate and distance isolation are also important factors in the formation of genetic structure of wild soybean.