簇毛麦4VS染色体结构变异系创制及抗小麦黄花叶病基因Wss1的染色体区段定位

栽培品种遗传基础日趋狭窄已成为小麦育种取得突破性进展的主要瓶颈。小麦近缘种属蕴藏丰富的基因资源，将其中的优良基因导入普通小麦，是拓宽小麦遗传基础、推进小麦育种取得突破性进展的有效途径。诱导创制外源染色体结构变异，既可促进外源优异基因有效利用，系列结构变异体也是外源基因定位、克隆和比较基因组学研究的重要材料。本项目前期研究中发现携带4VS染色体的小麦-簇毛麦异染色体系高抗小麦黄花叶病，将该基因定名为Wss1。本研究将利用抗病的4V（4D）代换系和T4VSo4DL易位系，综合利用ph1b突变体和电离辐射技术，高效诱致和精确鉴定涉及4VS不同区段和片段大小不同的结构变异体，对结构变异体进行黄花叶病抗性鉴定，更精确地定位Wss1基因。研究成果不仅为Wss1基因的克隆奠定材料基础，也可为小麦抗黄花叶病育种提供新的基因资源。

The genetic variability within cultivated wheat has been gradually eroded, which has become a major bottleneck for wheat breeding. The wild relatives of cultivated wheat represent a rich pool of genetic variation that has great potential for wheat improvement. These species exhibit huge diversity in phenotype and adaptation to a wide range of environments, desirable traits such as resistance or tolerance to biotic and abiotic stresses. The transfer of useful genes from wild species through wide hybridization and the development of alien chromosome lines will enrich the genetic diversity of crop breeding. The induced series of chromosome structural aberrants will provide useful genetic resources not only for wheat improvement, but also for fine mapping and cloning the interest genes located on alien chromosome as well as comparative genomics research.Wheat yellow mosaic virus(WYMV) disease has become one of the most serious diseases affecting wheat production in China. In our previous research, a WYMV resistance gene, Wss1, has been located on the short arm of 4V chromosome of Haynaldia villosa. In this proposal, using wheat-H.villosa disomic substitution line DS4V(4D) and T4VSo4DL translocation line developed in our lab, chromosome structural aberrants involving different region of chromosome 4VS will be induced through a combination of technique of both homoeologous chromosome pairing system (ph1b gene mutant) and ionizing-irradiation. These lines will be characterized for their chromosome constitution by FISH and marker analysis and evaluated for their resistance to WYMV. Wss1 gene will be further mapped to a smaller fragment regions of chromosome 4VS. The outcomes of this research will lay solid foundation for the utilization of Wss1 gene in breeding program as well as the cloning the target gene.