高粱种质资源SSR标记遗传多样性与农艺性状关联分析

Genetic Diversity and Association Analysis Using SSR Markers and Agronomic Traits in Sorghum

[目的]为充分了解高粱育种资源各性状特性,指导高粱杂交组合的配置及分子标记辅助育种,应用分子标记对高粱种质进行遗传多样性分析,并寻找部分与农艺性状相关联的分子标记。[方法]利用SSR(simple sequence repeat,SSR)标记分析55份高粱种质资源的遗传多样性,同时对8个农艺性状作表型鉴定,并利用GLM模型进行分子标记与农艺性状的关联分析。[结果]株高、穗宽、穗长、叶片数、旗叶长及宽等生长期性状都符合正态分布,单穗粒重和千粒重也符合正态分布;各供试材料的8个农艺性状均有极显著差异。10对SSR引物共扩增出64条带并检测到39个等位变异;多态性信息量(polymorphism information content,PIC)变化范围为0.685 6～0.948 3,平均为0.841 3; Shannon信息指数(I)和Nei’s基因多样性指数(H)平均为1.195 8和0.617 0。在遗传相似系数为0.731 7处UPGMA法将55份高粱材料聚为三大类,其中13份材料聚为A类,3份材料聚为B类,其余36份材料聚为C类。利用GLM模型分析结果表明,与穗宽、穗长、旗叶长、旗叶宽和千粒重5个农艺性状相关联的标记有4个,单个标记对表型变异的解释率为0.014 7～1.360 5。[结论]该研究为高粱种质资源精准分类、种质优势利用、育种效率提高等方面以及分子标记辅助育种提供基础资料。

[Objective]To understand the agronomic traits of sorghum germplasm and to direct sorghum hybrid combinations as well as molecular marker assisted breeding,the genetic diversity of sorghum germplasm was analyzed and the molecular markers associated with agronomic traits were searched.[Method]The genetic diversity of 55 sorghum germplasm resources were assessed by simple sequence repeat(SSR)markers.We identified the phenotypic of eight agronomic traits and found SSR markers associated with plant height,spike width,spike length,leaf blade number,flag length and width,spike weight and thousand-grain weight using GLM(General Linear Model).[Result]Eight agronomic traits were consistent with normal distribution and there are very significant differences,a total of 39 alleles were identified with 10 SSR markers.The average polymorphism information content(PIC)varied widely from 0.685 6 to 0.948 3 with an average value of 0.841 3,the average of Shannons information index(I)and Nei’s gene diversity index(H)were 1.195 8 and 0.617 0,respectively.Clustering analysis with UPGMA showed that the 55 materials could be divided into three groups at the genetic similarity coefficient of 0.731 7,thirteen materials were grouped into Class A,three materials were grouped into Class B,and the remaining thirty-six materials were grouped into Class C.Four markers were found to be associated with spike width,spike length,flag leaf length,flag leaf width and thousand-grain weight using GLM(General Linear Model),and the phenotypic variation explained by a single marker ranged from 0.014 7 to 1.360 5.[Conclusion]This research provided fundamental data for the accurate classification of germplasm resources,advantage utilization of germplasms,enhancement of breeding efficiency and molecular mark assisted breeding of sorghum.