小麦骨干亲本临汾5064单元型区段的遗传解析

Genetic Analysis of Haplotype-blocks from Wheat Founder Parent Linfen 5064

利用分子标记解析骨干亲本临汾5064单元型区段在其衍生后代中的遗传规律,可以为小麦分子育种提供依据。在临汾5064及其21个衍生品种(系)中,395个SSR标记共检测出895个等位变异,不同位点的等位变异为1~8个,平均2.27个,平均多态性指数为0.25。临汾5064及衍生后代中146个位点具有相同等位变异,遗传贡献超过80%的位点有30个。实验结果表明,临汾5064对衍生子一代和子二代的遗传贡献率分别为65.30%和64.24%,且未随着世代的增加而明显下降。所有衍生后代与亲本完全相同的单元型区段有16个,贡献率大于80%的染色体区段分布在所有染色体上。关联分析发现这些单元型区段存在重要农艺性状的QTL簇,几乎都与重要农艺性状显著相关,表明这些区段在育种过程中受到强烈选择。

The objective of this study was to provide essential basis for further utilization of Linfen 5064, an elite founder parent, through dissecting haplotype-blocks of Linfen 5064 transmitted to its progenies. A total of 895 alleles were detected on 395 SSR loci in Linfen 5064 and the 21 derived varieties（lines）, with 1–8 alleles per locus and an average of 2.27. The average polymorphism information content（PIC） was 0.25. On 146 loci, the alleles were identical between all derived varieties（lines） and the parent, and genetic contributions of the parent were higher than 80% on 30 loci. Generally, the genetic contributions of Linfen 5064 to the first-and second-derived generations were 65.30% and 64.24%, and the contribution ratio did not decrease significantly along with the increase of generations. Sixteen haplotype-blocks were inherited completely from the parent to all derived varieties（lines） and the haplotype-blocks with contribution ratios higher than 80% were distributed on all the 21 chromosomes. In combination with the results of association analysis, almost every haplotype-block was associated with QTLs controlling important agronomic traits, indicating these chromosomal segments were strongly selected in breeding programs.