小麦-四倍体长穗偃麦草易位系的分离、鉴定及优异基因发掘

小麦条锈病和白粉病是我国小麦生产中最重要的病害，发掘新的抗病基因、培育抗病品种是最有效的防治方法。四倍体长穗偃麦草提供了优异的抗源，为发掘和利用其优异基因，我们利用染色体工程方法创制了一个高抗条锈病和白粉病的小麦-四倍体长穗偃麦草3E/3D代换系材料。本项目旨在：（1）利用电离辐照、GISH、FISH方法分离鉴定一批小麦-四倍体长穗偃麦草3E染色体易位系材料；（2）采用GBS技术，开发不同大小易位片段特异的PCR标记，构建3E染色体物理图谱；（3）结合条锈病和白粉病抗性数据，物理定位外源片段携带的抗病基因；（4）将抗条锈病和白粉病基因转入小麦推广品种，结合PCR标记，获得具有外源抗性基因且综合农艺性状优良的小麦育种新材料。本研究结果将为四倍体长穗偃麦草优异基因在小麦改良中的利用及分子标记辅助选择奠定基础。

The stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) and powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) are most devastating diseases to wheat production in China. New disease-resistant genes and cultivars are the most effective means of reducing the amounts of fungicides applied to combat these diseases. tetraploid Thinopyrum elongatum (2n=4x=28, EEEE) is a potentially useful germplasm of resistance for wheat improvement. In order to transfer desirable genes from tetraploid Th. elongatum into wheat, we successfully produced a wheat-tetraploid Th. elongatum 3E/3D substitution line with high resistance to stripe rust and powdery mildew. Our aims in this program are: (1) to develop and characterize the wheat-tetraploid Th. elongatum 3E chromosome translocation lines using 60Co-γray irradiation, GISH and FISH techniques; (2) develop PCR markers that are specific to different chromosomal translocated segments using GBS analysis, futher construct the physical map of tetraploid Th. elongatum 3E chromosome; (3) map the novel stripe rust and powdery mildew resistance gene(s) to specific 3E chromosomal bins by combing the diseases resistance observation; (4) to transfer resistance genes into wheat cultivals using PCR markers, and develop the new wheat breeding materials with good agronomic traits and disease resistance. These works will lay a foundation for the utilization of tetraploid Th. elongatum elite genes in wheat improvement and marker-assisted selection.