小麦寡分蘖基因Ltn2D的精细定位、克隆及功能分析

分蘖是影响小麦穗数多少并进而影响单产的重要农艺性状，也是小麦品种理想株型的重要构成因子。本项目立足于前期研究中新发现的寡分蘖基因Ltn2D，利用该基因近等基因系构建的5个次级F2群体（合计21193个单株）精细定位Ltn2D基因；根据最新公布的小麦中国春参考基因组（IWGSC RefSeq v1.0）序列信息，结合前期已完成的多-寡近等基因系的转录组、蛋白质组数据，筛选并克隆候选基因；利用基因过表达和基因敲除技术获得转基因阳性植株，并进一步鉴定转基因后代与野生型植株的分蘖数、分蘖节组织结构特征等表型性状，验证候选基因的生物学功能。同时，利用目标性状EMS突变体互补验证候选基因对分蘖数表型的作用。为构建小麦分蘖形成与发展的分子理论体系奠定基础，服务于株型分子设计育种实践。

Tillering is one of the most important agronomic traits for grain yield and plans a key role in wheat ideotype. In our previous research, the novel gene (named as Ltn2D) for low-tiller number was identified, and five near isogenic lines (NILs) harboring this gene were developed for five secondary F2 populations containing 21,193 lines for fine mapping. Combing the results from fine mapping, the newest wheat reference genome sequence and RNA-seq and proteome data between high and low tiller NILs, the candidate genes will be screened and cloned. Moreover, transgenic technology and EMS mutant materials will be used to validate the biological function of the target genes, and the the molecular mechanism in the progress of low-number tillers controlling will be further revealed. This study will lay the foundation for constructing the theoretical system of tillering formation and development, and help us to practice the molecular breeding for plant type in wheat.