谷子分蘖相关QTL定位及紧密连锁标记开发

Mapping of Quantitative Trait Locus and Developing of Closely Linked Markers for Tillering in Foxtail Millet

分蘖是与农作物产量相关的重要农艺性状之一,分蘖对于谷子产量的提高具有重要意义,但是目前谷子分蘖遗传分子机制还不清楚。利用简化基因组测序技术(RAD-seq),以2个F2群体(命名为Cross AJ和Cross HC)为研究对象,分别对2个F2群体的543个和131个单株及其亲本进行RAD-seq,利用MSTmap和Win QTLCart 2. 5软件进行遗传图谱构建和QTL分析,结果共鉴定出8个控制分蘖相关的QTL。其中,利用Cross AJ共鉴定了6个QTL,分别为qAJTN1、qAJTN5、qAJTN7-1、qAJTN7-2、qAJTN7-3和qAJTN9,可解释表型变异0. 7%～9. 8%;利用Cross HC群体共鉴定了2个QTL,分别为qHCTN5和qHCTN7,可解释表型变异1. 4%～8. 3%。在这8个QTL中,qAJTN1、qAJTN5、qAJTN7-2、qAJTN9和qHCTN5为该研究新鉴定的位点,其余3个QTL(qAJTN7-1、qAJTN7-3和qHCTN7)与前人研究结果相一致。另外,通过将亲本的测序结果与参考基因组进行比对,搜索插入缺失位点InDel(Insertion-deletion),新开发了谷子分蘖相关QTL(qAJTN7-3和qHCTN7)紧密相关的InDel标记。结果为谷子分蘖机制的研究奠定一定基础,所开发的分子标记对于分蘖型谷子的分子标记辅助育种具有重要意义。

Tillering is an important trait related to yield in many crops,and is the same for yield improvement of foxtail millet.However,the genetic mechanism of tillering in foxtail millet(Setaria italica)remains largely unknown.To accelerate mapping of relevant QTLs or genes,a restriction site-associated DNA sequencing(RAD-seq)approach,MSTmap and WinQTLCart2.5were employed to identify QTLs responsible for tillering in two F2populations called Cross AJ(543F2individuals)and Cross HC(131F2individuals).A total of six QTLs including qAJTN1,qAJTN5,qAJTN7-1,qAJTN7-2,qAJTN7-3and qAJTN9,were identified in Cross AJ,explaining0.7%-9.8%of the phenotypic variance,and two QTLs including qHCTN5and qHCTN7were identified in Cross HC,explaining1.4%-8.3%of the phenotypic variance.Of which qAJTN1,qAJTN5,qAJTN7-2,qAJTN9and qHCTN5were newly identified QTLs,and qAJTN7-1,qAJTN7-3and qHCTN7were consistent with previous reports.Meanwhile,we screened the insertions and deletions in the QTL regions compared with the reference genome,insertion-deletion(InDel)markers linked with tillering were developed.These results of this study will facilitate the revelation of the genetic mechanism of tillering and molecular marker-assisted breeding of foxtail millet.