小麦-偃麦草创新种质CH7086中抗条锈病基因Yr69的精细定位

Stripe rust (Yr), caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases in the wheat production worldwide. The development and usage of new gene is crucial to breeding for cultivar conferring resistance to the diseases. CH7086, a new wheat-Thinopyrum ponticum germplasm, is resistant to wheat stripe rust. We have identified a new gene designated officially Yr69 for resistance to stripe rust in CH7086. And Yr69 has been located on 2AS of wheat in our previous study. The aim of this project was to construct high density genetic linkage map of gene Yr69 via the F2 populations derived from crossing CH7086 with Taichung 29 using developing or developed SSR and CAPS markers. This project will provide the fine mapping and markers tightly linked to Yr69 which be beneficial to marker-assisted selection (MAS) in wheat breeding programs and map-based cloning of Yr69 genes.

条锈病是小麦的重要病害之一，发掘和利用新的条锈病抗病基因，选育持久抗病品种是防治小麦条锈病最经济有效的方法。CH7086是小麦-偃麦草创新种质，高抗小麦条锈病，前期研究结果显示，在该种质2AS染色体上含有一个抗小麦条锈病新基因Yr69。本研究拟通过构建F2大群体，利用BSR分析结合比较基因组学分析，设计开发多态性SSR和CAPS标记，实现对Yr69精细定位，为分子标记辅助选择抗条锈病小麦新品系和图位克隆Yr69基因奠定基础。

本项目利用小麦白粉病生理小种E09对小麦-偃麦草新种质CH7086与感病小麦品种台长29杂交的F2代单株进行苗期抗病性鉴定。利用BSR-seq技术对抗病亲本、感病亲本、50个F2代抗病单株构建的抗病池和50个F2代感病单株构建的感病池进行测序分析，将抗病基因Pm51定位在2B染色体长臂54.91 Mb区间内。q-PCR验证三个区间内的非同义突变基因，并利用KASP分型技术对三个区间中的SNP位点进行标记开发。将抗病基因载体品种CH7086（Yr69和Pm51）与小麦生产上大面积推广的优良品种进行多重杂交和回交。对高代品系进行抗病性鉴定和分子标记检测，通过分子标记辅助育种淘汰不含有抗病基因的品系，选育出多份兼抗白粉病和条锈病小麦新品系。对小麦-偃麦草抗病新种质CH5389中的条锈病抗病基因进行了抗病性鉴定，遗传分析表明，CH5389中包含有一对显性抗条锈病基因YrCH5389，进一步通过分子标记和比较基因组学分析将YrCH5389定位到小麦染色体3AL端部。