培育利用抗病新品种是防治小麦白粉病危害最经济有效的途径。发掘利用亲缘种属抗病基因是培育抗病品种，保障小麦安全生产的迫切需求。本申请人鉴定到高大山羊草6Sl#3染色体携带广谱抗白粉病新基因Pm6Sl，抗全国26个白粉菌优势菌株中的24个。在此基础上，本项目拟：(1)利用诱发部分同源染色体高频重组基因(ph1b)诱导小麦-高大山羊草6Sl#3小片段易位系，创制抗白粉病新种质；(2)利用小麦-高大山羊草抗病6Sl#3与感病6Sl#2附加系杂交构建作图群体，基于6Sl#3/6Sl#2同源染色体重组对Pm6Sl进行精细定位；(3)通过基因图位克隆和Pm6Sl感病突变体的抗病基因富集测序(RenSeq)双重途径分离Pm6Sl候选基因，并用基因沉默和转基因互补表达验证功能。项目完成后可获得自主产权新基因，为下一步克隆Pm6Sl基因，解析其抗白粉病的分子机理奠定基础，并为小麦改良提供抗白粉病新种质。

Development of new varieties with disease resistance is considered a most economic and environment-friend approach to protect wheat plants from damages caused by Blumeria graminis f. sp. tritici (Bgt). So, exploration and utilization of alien resistant resources from wild relatives of wheat is in urgent need to breed disease resistant varieties, and guarantee wheat production safety. We have recently identified a novel gene conferring broad-spectrum resistance against powdery mildew located on chromosome 6Sl from Aegilops longissima and temperately designated it as Pm6Sl. It is resistant to 24 out of 26 Bgt dominant strains collected from different areas in China. Here we propose this project for the transfer of Pm6Sl into wheat based on homoeologous recombination induced by ph1b gene which can significantly promote homoeologous chromosome pairing and recombination in wheat cells. Fine mapping of Pm6Sl will be conducted based on homologous recombination between 6Sl#3 and 6Sl#2 chromosome by using genetic mapping population derived from the cross between resistant 6Sl#3 addition line and susceptible 6Sl#2 addition line. Meanwhile we plan to isolate Pm6Sl gene candidates by both map-based cloning and mutagenesis and R-gene enrichment sequencing (MutRenSeq) based on EMS-induced mutants with loss of resistance to powdery mildew. Then function of candidate genes of Pm6Sl will be verified based on virus-induced gene silencing and complementary expression in transgenic plants. The accomplishment of the project will obtain novel resistant genes with independent intellectual property, lay the foundation for further cloning of Pm6Sl and understanding of the molecular mechanism of resistance to powdery mildew initiated by Pm6Sl gene in wheat, and provide novel powdery mildew-resistant germplasm for wheat improvement.