湖南新田大冠岭野生大豆居群遗传结构与空间分布关系

摘要

Objective]To explore the information of development and differentiation of special micro-envi-ronment of wild soybean for sampling wild soybean .[Method] A total of 41 simple sequence repeat ( SSR) markers scattered on the whole genome were used to analyze the genetic diversity and genetic structure , and to evaluate the relationship between genetic diversity and spatial distribution of the 16 wild soybean populations with a sample of 612 individuals around Daguanling in Xintian County , Hunan Prov-ince.[Result and conclusion] A total of 414 alleles were detected with 41 SSR marks among 612 acces-sions, and the average number of allelic variations per locus was 10.1, ranging from 4 to 19.The average Shannon’s information index (I) per locus was 1.751 with a range of 0.283-2.542.It was discovered that the region from Xiangxiling to Sangzi had a higher genetic diversity and more allelic variations than other regions , and also had a higher gene flow than the other populations by comparing genetic diversity index of different populations .The wild soybean accessions could be divided into 19 sub-groups by the a-nalysis of population structure with software Structure 2.3 based on mixed model .The populations near the region from Xiangxiling to Sangzi were divided into different sub-groups and the populations far from Daguanling were clustered into different groups separately .There was a positive correlation between ge-netic distance and geographic distance under the condition that the sample ’ s distance was less than 1 400 m.The region from Xiangxiling to Sangzi was a diversity center of wild soybean in Daguanling region . Populations near the region apparently had the character of spatial distribution .Genetic diversity was pos-itively correlated with geographic distance and altitude .The population of wild soybean in Daguanling dis-perse from high altitude to low altitude .The spread model of this region is distance model and continent-island model .%【目的】揭示野生大豆Glycine soja Sieb．et Zucc．在特定微环境中演化和分化的信息，为自然居群的取样提供理论依据．【方法】采用41对SSR引物对湖南新田大冠岭地区及其周围的16个居群612份野生大豆材料的遗传多样性和群体结构进行了分析，并分析了居群多样性与空间分布间的关系．【结果和结论】41个SSR位点在612份野生大豆材料中共检测出414个等位变异，每个位点的等位变异范围为4～19个，平均为10.1个．每个位点Shannon指数（I）变异范围为0.283～2.542，平均为1.751．通过比较不同居群遗传多样性指数，发现大冠岭区域向西岭至桑梓一带野生大豆遗传多样性丰富，拥有较多的等位变异，与其周围居群间有较高的基因流．用基于混合模型的Structure2.3软件分析群体结构，可将野生大豆居群分为19个组群，大冠岭区域向西岭至桑梓一带野生大豆居群互混成不同组，而远离大冠岭的野生大豆居群则大都独立．空间自相关分析显示，1400 m以内遗传距离与地理距离呈正相关；向西岭至桑梓一带是大冠岭区域野生大豆居群的一个多样性中心，周围野生大豆自然居群呈现出明显的空间分布特点，遗传多样性与地理距离、海拔呈正相关，大冠岭野生大豆传播方式为由高海拔地区向低海拔辐射传播．因此认为该地区野生大豆遗传结构模式应属于距离隔离模式和陆岛模式．