小麦成株期抗叶锈病新基因Lr16G216的精细定位和候选基因克隆

小麦叶锈病是危害小麦生产的重要病害之一，挖掘和鉴定抗病基因是培育抗病品种的关键。前期以成株抗叶锈病亲本‘扬16G216’和感叶锈病亲本‘扬16M6393’杂交并构建了RIL群体，基于“55K SNP芯片-BSA”策略，在6B染色体长臂末端(712.3～714.6 Mb)定位到一个新的小麦成株期抗叶锈病主效基因Lr16G216。本研究拟通过构建次级F2大规模群体，利用660K SNP芯片、外显子捕获及‘中国春’参考基因组序列，开发靶区间多态性标记，构建高密度连锁图谱，实现对Lr16G216的精细物理定位，挖掘候选基因；通过EMS诱变创制感病突变体，对目标区域进行捕获测序，通过与野生型基因序列比对和筛选高频SNP基因座，推定候选基因；利用VIGS基因沉默、CRISPR基因敲除及转基因技术进一步验证候选基因功能。本项目成果将为小麦抗叶锈病品种选育提供重要基因资源、实用标记和优异种质。

Wheat leaf rust is one of the most devastating diseases of wheat. Discovery and identification of new resistance genes is essential to develop disease-resistant cultivars. In the previous studies, a recombinant inbred line (RIL) population from the cross between ‘Yang16G216’ conferring adult plant resistance (APR) to leaf rust and susceptible cultivar ‘Yang16M6393’ was constructed. A new major APR gene, Lr16G216, was then mapped to a distal interval (712.3 ~ 714.6 Mb) on chromosome 6BL, based on the "55K SNP array-BSA" strategy. In the present project, a large secondary F2 population will be constructed, and the 660K SNP array, exome capture sequencing, and Chinese Spring reference genome sequence will be used to develop molecular markers spanning the target interval. A high-density linkage map covering Lr16G216 will be constructed to finely map Lr16G216 and predict candidate genes. Mutagenesis via EMS will be conducted to create susceptible mutants. Putative candidates will be confirmed by screening of high frequency SNP gene loci based on sequence alignments. Virus induced gene silencing (VIGS), gene knockout by CRISPR/Cas9, and transgenic technologies will be carried out to verify the function of candidate genes. Results of this project will provide an efficient leaf rust resistance gene, breeder-friendly molecular markers, and elite germplasm to wheat resistance breeding.