分蘖是影响小麦产量的关键因素之一。研究影响小麦分蘖发生的机理，对于提高小麦产量具有潜在的应用价值。本课题组前期研究表明，TaD27s通过调控小麦独脚金内酯的合成，进而影响小麦分蘖数目。研究并应用该基因的优异单倍型（优异等位变异），是将该基因的功能利用到最优化的关键。通过筛选345份小麦种质中TaD27s的单倍型，发现单倍型TaD27-X与多分蘖表型显著相关，其对小麦分蘖数目的影响优于该基因其它单倍型的作用，推测TaD27-X是增加小麦分蘖数目的优异单倍型。本项目将在现有研究基础上，完成以下工作：（1）完成优异单倍型TaD27-X的功能验证及初步的机理研究，探究导致TaD27-X的功能优于其它单倍型的关键因子；（2）开发TaD27-X的功能标记，培育携带TaD27-X的优良新种质，为小麦高产育种积累中间材料。本研究对解析优异单倍型TaD27-X的作用机理、推动其在小麦育种中应用具有重要意义。

Tiller number is one of the important factors affecting wheat yield. It has potential application value for improving wheat yield to investigate the molecular mechanism of regulating the tiller in wheat. In our previous study, it has been confirmed that TaD27s regulated the synthesis of endogenous strigolactone (SLs) and further affected the tiller number. To study and apply the elite haplotypes (elite allelic variations) is the key to optimize the function of this gene. Recently, we screened 345 wheat germplasms and found that haplotype TaD27-X was significantly correlated with the increase of tiller number. The effect of TaD27-X on tiller number was significantly greater than that of other haplotypes, which suggesting that TaD27-X was an elite haplotype for increasing wheat tiller number.In this project, we will mainly carry out the following work as two parts: (1) Investigating the function and molecular mechanism of elite haplotype TaD27-X, exploring the key factors that lead to excellent function of TaD27-X ; (2) Exploiting the functional markers of TaD27-X and breeding the new germplasms carrying TaD27-X, which will accumulate the intermediate materials for applying this haplotype in further practical breeding work. Our research will be significant to elucidate the mechanism of elite haplotype TaD27-X and promote its application in wheat breeding.