锂离子束诱变创制小麦突变体中茎秆发育调控基因qd1的精细定位与育种可利用性研究

基于核辐射诱变技术的作物种质资源和基因资源创新是拓宽遗传基础、深化理论研究和加强优良品种培育的重要基础和保障。申请者针对7Li离子束诱变创制的小麦茎秆发育突变体，完成了表型精准鉴定，明确了赤霉素对茎秆发育表型的调控基础，初步定位了突变基因（命名为qd1），开发了205个初定位区间内的多态性分子标记。在此基础上，本项目将围绕qd1在基础理论创新和育种可利用性两方面的价值评估，开展以下研究：1）利用分离大群体进行qd1的精细定位；2）利用已有高代回交群体构建qd1基因近等基因系；3）明确qd1与Rht-1/Rht-2的遗传互作关系并解析Rht-1存在条件下qd1促进小麦茎秆伸长的作用机制；4）评价在不同生态类型条件下qd1对重要农艺性状的影响，初步阐明该基因的育种可利用价值。本项目研究结果将为我国以茎秆改良为目标的小麦育种实践提供新的基因资源，并为进一步解析小麦茎秆发育调控机理提供理论依据。

Crop germplasm and gene innovation based on radiation induced mutation provide important support for extending genetic base, deepening basic theoretical studies, and promoting new elite varieties cultivation. Using 7Li ion beam mutagenesis, the applicants of this project successfully screened the wheat quick development mutant. We have characterized the mutant phenotype in detail, demonstrated the gibberellins’ role in mutant stem development, localized the mutated gene (name qd1), and developed 205 polymorphism markers in qd1 locating region. Based on above results, this project will focus on evaluating the qd1 value for both theoretical innovation and breeding utilization. We will carry out the research in the following 4 aspects: 1) fine mapping the qd1 gene using big segregating population; 2) conducting near isogenic lines of qd1 using backcross lines; 3) dissecting the genetic interaction between qd1 and Rht-1/Rht-2, and the mechanism of promoting stem development by qd1 in the presence of Rht-1; 4) Preliminary demonstrating the breeding utilizing value of qd1 by testing the important agronomic traits in different ecological districts. Through this project, we will provide a new gene for wheat breeding program which aims to improve stem characteristics, and provide a solid theoretical basis for better understanding the stem development regulation.