基于分型测序技术的粒用高粱遗传多样性和群体结构分析

Genetic Diversity and Population Structure Analysis of Grain-use Sorghum Based on Genotyping by Sequencing Technology

了解粒用高粱的遗传多样性和群体结构,能有效提高粒用高粱新品种的选育效率。本研究利用基因分型测序技术(GBS,genotyping by sequencing)对120份粒用高粱材料开展了全基因组基因分型,共获得了3456个多态性的SNP标记,其多态性信息含量指数(PIC,polymorphism information content)介于0.013～0.574之间,平均值为0.381。根据SNP标记在120份高粱材料中的基因分型数据,计算了材料间的遗传距离,其变异范围为0.084～0.613,平均遗传距离为0.365。群体进化树分析和主成分分析都将120份高粱材料划分为3个类群,类群1主要由包括美国材料MN-3609在内的亲缘关系较远的高粱材料组成,类群2主要由中国北方的高粱材料组成,类群3主要由中国南方的高粱材料组成。群体结构分析表明,当K=3时,ΔK取得最大值,说明120份高粱材料可以划分为3个类群,其划分结果与群体进化树分析和主成分分析基本一致。本研究从基因型多样性水平上阐释了粒用高粱的遗传背景和群体结构,为中国粒用高粱新品种的选育提供了理论依据。

Understanding the genetic diversity and population structure can effectively improve the breeding efficiency of grain sorghum new cultivar.In this study,genotyping by sequencing(GBS)technology was deployed to unlock the genetic diversity in a collection of 120 grain sorghum materials.Within 3456 SNP markers that were generated,the polymorphism information content(PIC)ranged from 0.013 to 0.574,with the average of 0.381,while SNP-based genetic distance value ranged from 0.084 to 0.613,with the average of 0.365.Both phylogenetic tree analysis and principal component analysis indicated that 120 grain sorghum genotypes were clustered into three groups.Group-1 was mainly composed of sorghum materials with a relatively distant relationship,including the USA material MN-3609.Within Group-2 and group-3,these genotypes were mainly collected from northern and south parts of China,respectively.Population structure analysis showed that the maximum ΔK was observed for K=3,suggested three sub-populations detected in 120 grain sorghum materials.This result was consistent with phylogenetic tree analysis and principal component analysis.Taken together,this resulted deciphered the genetic background and population structure of grain sorghum from the genotype diversity level,which will provide theoretical basis in breeding for grain-use sorghum new cultivar in China.