小麦-中间偃麦草异代换系/易位系筛选和抗条锈病遗传基础研究

The relative species of wheat has the extraordinary rich genetic diversity and excellent genes,so it is very important meaning for wheat production and breeding to strengthen, identify and utilizate the research of the cross between wheat and the relative species.Total 12 alien substitution of common wheat - Thinopyrum intermedium with good agronomic characters and resistance to wheat stripe rust, which were obtained by crossing and backcrossing, are taken as the research material in this study. The types of substitution lines: single substitution lines and double substitution are identified through cytology and hybridization. 3-4 alien substitutions or translocation lines were selected and bred. In order to clarify the characteristics of genetic resistance to stripe rust, alien substitution and translocation lines are choosen respectively and crossed with Ming xian 169 to obtain the generations of F1, F2, F3 and BC1, which are inoculated by pathogen of wheat stripe rust in the field for genetic analysis. Meantime molecular markers such as AFLP and SSR are applied for location of resistance gene. That will be help to know the number of resistance genes to stripe rust in alien substitution or translocation lines, discover 1-2 new genes/QTLs, and stock material for resistance breeding to wheat stripe rust.

小麦近缘属种存在着极为丰富的遗传多样性和优异基因，加强小麦与其近缘属种的杂交、鉴定和利用研究，对小麦生产和育种具有重要意义。本研究以杂交和回交培育的农艺性状良好且抗小麦条锈病的12个普通小麦-中间偃麦草异代换系为研究材料，通过细胞学检测和原位杂交鉴定，明确异代换系的类型：单体代换系和二体代换系，选育异代换系或易位系3-4个；分别选择异代换系和易位系与铭贤169杂交，获得的F1、F2 、F3及BC1 代，田间接种小麦条锈菌进行遗传分析，明确其抗条锈性遗传特点；同时应用AFLP和SSR等分子标记技术进行抗病基因定位。以明确异代换系/易位系抗条锈病基因数目，发掘抗条锈病异源新基因/QTLs 1-2个，为小麦条锈病抗病育种贮备材料。

中国是世界上小麦条锈病(Puccinia striiformis Westend f.sp.tritici) 最大的流行区，利用抗病品种是控制该病害最经济、安全、有效的方法。小麦近缘种中间偃麦草是小麦遗传改良的重要基因源，对条锈病菌具有很好的抗病性。本项目以杂交和回交培育的农艺性状良好且抗小麦条锈病的12个普通小麦-中间偃麦草异代换系为研究材料，采用抗病性鉴定等方法，通过细胞学和原位杂交检测，鉴定和筛选到了7个普通小麦－中间偃麦草的抗条锈病异代换系或易位系P6，14，30，38，58，69，71；对其与感病亲本Taichung 29进行杂交，获得的F1、F2及BC1代，田间接种小麦条锈菌CYR32,明确了其中P58抗条锈性由一对显性基因控制，该基因来源于中间偃麦草，利用小麦染色体上的SSR引物对一套中国春缺体-四体系、P58、Taichung 29、ph1b、中间偃麦草进行PCR扩增，表明P58的抗病基因来源于中间偃麦草。获得的普通小麦—中间偃麦草抗病材料可作为小麦条锈病抗源在育种中应用。