利用SSR标记评价抗胞囊线虫野生大豆种质的遗传多样性

Genetic Diversity of Wild Soybean( Glycine soja ) Resistant Germplasms to Soybean Cyst Nematode Revealed by SSR Markers

大豆胞囊线虫病是大豆生产上的主要病害之一，给大豆生产造成巨大损失。利用分布在大豆20个连锁群的49个SSR分子标记分析了25份抗胞囊线虫病野生大豆种质的遗传多样性及其与8份国内外常用栽培大豆抗源间的遗传关系。供试的25份抗病野生大豆种质具有较高的遗传多样性，在49个SSR位点上共鉴定出516个SSR等位变异，其中稀有等位变异232个；平均有效基因数为6．93，期望杂合度为0．8335。利用STRUCTURE软件进行遗传结构分析发现，供试种质被归人6个类群（C1～C6），其中8份栽培大豆抗源均被聚类在C2类群。采用POWERMARKER软件进行的NJ聚类结果与遗传结构分析结果一致。结果为野生大豆抗病种质在研究和育种中的合理利用提供了参考。

Soybean cyst nematode（SCN） （Heterodera glycines Ichinohe）is one of the most worldwide devastating pests in soy-bean production. Wild soybean（ G. soja）is an invaluable gene pool for the genetic improvement of soybean ,which probably has genetic variations not present in domesticated soybean（ G. max）collection, mining of novel resistant accessions and genes from wild soybean germplasm has become a major objective in soybean research. In the present work,49 SSR markers were selected based on their distribution on the 20 genetic linkage groups of soybean for genetic diversity investigation of 25 G. soja SCN race 3-resistant accessions and for their genetic relationship analysis with 8 G. max resistant resources, which were frequently used in breeding program and genetic mapping. High genetic diversity of 25 G. soja resistant accessions were present with 516 alleles in total and 232 rare alleles at 49 SSR loci. The average effective number of alleles and expected heterozygosity were 6.93 and 0. 833 5, respectively. Significant population structure existed among the 33 resistant accessions ,6 clusters（C1-C6） were distin- guished using a model based Bayesian clustering method in STRUCTURE, all of 8 G. max resistant resources were clustered in- to C2. The neighbor-joining trec made in POWERMARKER supported the clustering result. The molecular genetic diversity provided vital information for rational utilization of G. soja resistant accessions.