兼抗小麦条锈和叶锈病成株抗性新位点QYr.cim-1BL.2/QLr.cim-1BL.2候选基因挖掘及功能解析

有效利用兼抗条锈病和叶锈病成株抗性基因是培育小麦持久抗性品种的重要途径。申请人所在课题组前期在Apav#1/Ableu#1重组自交系群体中鉴定到一个兼抗两种病害成株抗性的新位点QYr.cim-1BL.2/QLr.cim-1BL.2，对应于中国春1.1版本基因组上1B染色体678.7-680.2 Mb区间，包含16个注释基因，其中8个与抗病相关。基于单标记分析将筛选到的仅含有目标抗性位点的单基因系AA1409分别与感病亲本Apav#1和感病家系AA1449杂交构建遗传群体。基于此，本项目拟以F2:3、F3:4和F4:5次生群体及目标基因的EMS突变体为材料进行该位点的精细定位，通过比较候选基因在抗感亲本间和突变体间的序列差异，分析表达模式，确定最终候选基因，并通过转基因过表达和基因编辑等技术对其进行功能验证，为培育持久兼抗条锈病和叶锈病小麦新品种提供新基因资源。

Utilization of the pleiotropic adult plant resistance (PAPR) gene is a main strategy to develop durable resistant wheat varieties to both stripe rust and leaf rust. Previously, our research group mapped one new PAPR locus, tentatively designated as QYr.cim-1BL.2/QLr.cim-1BL.2, on wheat chromosome 1BL from an RIL population of Apav#1/Ableu#1. The physical position of this locus was located at the interval of 678.7-680.2 Mb, including 16 putative protein coding genes, in which 8 genes showed association with disease resistance based on the gene annotation of wheat reference genomes. In this proposal, we are going to phenotype the QYr.cim-1BL.2/QLr.cim-1BL.2 single gene segregating populations of F2:3, F3:4 and F4:5 derived from the crosses of Apav#1/AA1409 and AA1449/AA1409, respectively, as well as the EMS-induced mutants of the single gene resistant line AA1409. BSR-Seq approach and wheat 1BL genome sequences will be used to develop the closely linked or co-segregated molecular markers for QYr.cim-1BL.2/QLr.cim-1BL.2. Based on the fine mapping results, sequence variations and gene expression patterns of the predicted genes in the physical mapping interval will be compared between the susceptible parent Apav#1, single gene resistant line AA1409, and EMS-induced susceptible mutants to determine the candidate genes. Finally, functional validation of the candidate gene will be verified by transgenic overexpression and CRISPR/Cas 9 genome editing technologies. This research will provide a new gene for molecular mechanism characterization of PAPR and functional molecular markers for wheat breeders to develop durable pleiotropic resistant wheat varieties.