小麦Ph1基因抑制位点Su1-Ph1的精细定位和候选基因分析

Ph1基因限制了小麦与近缘种属部分同源染色体间的重组交换，阻碍了其中优异基因的挖掘利用，是小麦遗传资源有效利用的瓶颈。本研究前期发现拟斯卑尔脱山羊草带有Ph1基因的抑制位点Su1-Ph1，将其渐渗到了四倍体小麦3A染色体的长臂21Mb区域，为挖掘小麦近缘种属的优异基因资源提供了新方法。前期通过拟斯卑尔脱山羊草分离群体将Su1-Ph1初步定位到XBF429350和Xpsr1205之间5.5cM区间。本项目拟以独特渐渗系LDN-Su1-Ph1为研究对象，通过组学分析辅助图位克隆的方法，开发多态性分子标记，筛选回交分离群体，构建Su1-Ph1的遗传图谱，对其进行精细定位；通过构建物理图谱和分析转录组差异基因，预测候选基因；通过候选基因的单倍型分析，开发功能性分子标记，探究部分同源染色体间配对重组的遗传机制。本研究将突破小麦近缘种属遗传资源有效利用的瓶颈，为优异基因的挖掘和利用奠定理论基础。

The presence of the wheat Ph1 locus, which inhibits recombination between homoeologous chromosomes, is a bottleneck of wheat relative species utilization. Su1-Ph1, a major suppressor of the wheat Ph1 gene, was previously introgressed from Aegilops speltoides into 3AL chromosome of durum wheat cv Langdon (LDN), and the introgression segment was about 21Mb. Su1-Ph1 provides an alternative method to mine wheat relative gene pool by inducing homoeologous chromosome recombination. We previously anchored Su1-Ph1 into a 5.5cM genetic region, flanked by XBF429350 and Xpsr1205. This proposal aimed to do fine mapping and predict candidate gene of Su1-Ph1. A pentaploid backcross segregation population was designed and polymorphic molecular markers will be developed using comparative genomic and transcriptomic analysis. High density mapping of Su1-Ph1 and closely linked markers will be developed to accelerate its identification. Screening and sequencing the fosmid libraries and differently-expressed genes analysis will contribute to the prediction of the candidate gene. The project will be meaningful for the mechanism of homoeologous chromosome pairing and recombination, and also valuable for gene mining from wheat relative gene pool.