一组水稻种质资源的遗传相似性及群体结构分析

Genetic Similarity and Population Structure in a Rice Drought Stress Adaptation Panel

育种的成功基于试验材料中具有可利用的遗传变异,了解种质资源的群体机构及遗传变异范围是作物遗传改良的先决条件。本试验通过利用每3 Mb bin均匀分布于水稻染色体的156个SSR标记子,分析了一组(184个)用于干旱适应性研究的水稻种质资源的遗传相似性及群体结构。结果显示,水稻中确实存在着可供利用的遗传多样性,但也存在着普遍的遗传相似性,如国际水稻所的IR品种及菲律宾国家水稻所的PR及BP水稻品种。通过利用Structure中的混合模型对该184个水稻品种在K=3和K=7时的分析表明,群体结构普遍存在于相同类型或亚种的水稻品种中,籼稻及粳稻品种具有相对明显的群体结构,同一亲本的衍生后代具有显著的遗传相似性和群体结构,不同的群体均存在一定程度的遗传混合。对该组干旱适应性水稻种质资源的遗传相似性及群体结构的研究为今后的抗旱性基因的联合作图,也为合理选择亲本进行水稻抗旱性改良提供了有价值的遗传信息。

The success of plant breeding the population structure and range of diversity in all crop species. In this study, the authors is based on the availability of genetic variation. Understanding in available germplasm is fundamental for genetic improvement analyzed the genetic diversity and the population structure of a drought stress adaptation panel （184 rice genotypes） through 156 SSR markers nearly evenly distributed across the rice genome at every 3 Mb bin. The results indicated that large range of genetic diversity existed among rice germplasms, while some accessions exhibited comparatively higher genetic similarity, such as IR designat- ed varieties from IRRI and BP and PR designated varieties from PhilRice. The results of population structureof the 184 rice genotypes analyzed when K = 3 and K = 7 through the mixed model of STRUCTURE indicated ： population generally existed in the same type or rice subspecies ; indica and japonica had relatively distinguishable population structure; derivatives of the same parents had significantly higher genetic similarity and were generally clustered into the same subpopulation arid to various extents, genetic admixture existed within all the subpopulations. The study on the genetic similarity and population structure of this rice drought stress adaptation panel provides valuable genetic information for further association mapping for drought tolerance and selecting parental lines for crop improvement.