小麦秆锈病是一种世界性病害，其强毒新小种Ug99对我国小麦生产构成了巨大的潜在威胁。我国现有品种秆锈病抗源比较单一，特别是能抵抗Ug99的更少。簇毛麦6VL染色体上携有抗Ug99的Sr52基因，是拓宽小麦品种抗秆锈病遗传基础的新种质。本项目以创制的小麦-簇毛麦T6VL/6AS易位系为基础，借助染色体分拣和高通量测序相结合，开发簇毛麦6VL专化分子标记；对中国春ph1b突变体和电离辐射结合法诱致的簇毛麦6VL结构变异体进行分子标记鉴定，获得片段大小不同的易位系、缺失系和渐渗系；与肯尼亚国家农业研究院合作，在Ug99病发地进行抗病性的田间和温室鉴定；根据异染色体结构变异系的多年抗性鉴定结果，结合分子标记分析，将Sr52基因定位在6VL更小的染色体区段。本研究结果可为克隆Sr52基因提供新材料，还可为小麦Ug99抗病育种提供新种质。

Stem rust is one of the most devastating diseases of wheat crops globally. The emergence of a highly virulent Pgt race in Uganda in 1999, commonly known as Ug99, has become a threat to global wheat production. The cultivated wheat gene pool has a narrow genetic base for resistance to Ug99 and up to 90% of world’s wheat cultivars are considered Ug99 susceptible. Sr52, which confers resistance to Ug99, has been located on the long arm of 6V chromosome of Haynaldia villosa, the wild relative of cultivated wheat. This gene is a new source of resistance to Ug99 and may be useful in wheat improvement. In this proposal, a structural aberrant pool of chromosome 6VL involving different regions of chromosome 6VL including the translocations, deletions and introgressions will be induced through an integrated technique of homoeologous chromosome pairing system (ph1b gene mutant) and ionizing-irradiation. The 6VL genome sequences by flow sorting and next generation sequencing of the 6VL telosomic addition line will be used for the development of alien chromosome 6VL specific molecular markers. Seedling and adult plant resistance of these structural aberrants will be evaluated in the field and greenhouse in Kenya. The structural aberrants will be characterized for their chromosome constitution by marker analysis and for their stem rust resistance. The Sr52 gene will be further mapped to a smaller fragment region of chromosome 6VL. The outcomes of this research will lay solid foundation for the utilization of Sr52 gene in cloning the target gene as well as the wheat breeding program.