基于SNP芯片技术的小麦兰天26号抗条锈病基因定位及遗传图谱构建

Wheat stripe rust is a destructive disease which has seriously influence on the wheat production in China. Breeding resistant cultivars, knowing about the constitutes of resistance genes, knowing genetic characters and using of resistance cultivars reasonable is the key to control stripe rust. Lantian26 came from German Flanders with elite resistant genes, conferring adult plant resistance to current important races CYR34, CYR33 and mixed strains. It is effective resistance to wheat stripe rust many years in Longnan of Gansu. Lantian 26 is widely cultivated as a typical resistant variety in Gansu, but its resistance genes and the resistance mechanism haven’t been researched at present. The purpose of this study is to characterize the stripe rust resistance genes in Lantian26, identify tightly linked molecular markers and construct of genetic linkage map by SNP GeneChip, SSR and EST. A segregation population was derived from a cross between Lantian26 and susceptible cultivar Mingxian169. Major Chinese stripe rust races will be used to test Lantian26, Mingxian169 and the F1, F2 and F2:3 populations. The result is to be better reveal the molecular mechanisms of resistance disease and the functions of resistance genes. It will provide some scientific basis for breeding new resistance cultivars in the future.

小麦条锈病是严重影响我国小麦生产的毁灭性病害。选育抗病品种以及明确重要抗源材料中的抗病基因类型及其遗传规律是抗病品种合理布局的关键。兰天26号是源于国际持久抗条锈病品种Flanders的新抗源材料，成株期对强毒性CYR34、CYR33等生理小种及混合菌表现免疫，在甘肃陇南等条锈病常发易变区多年种植持续高抗条锈病，是甘肃小麦条锈病控制基因布局中的代表品种，但目前对其抗病基因类型及抗病机理尚不明确。本研究以抗病品种兰天26号和感病材料铭贤169为亲本，建立F1、F2和F2:3代杂交群体，采用我国条绣菌当前主要流行小种和重要致病类型接种群体材料，研究兰天26号抗病基因类型及抗病遗传规律；利用SNP芯片技术并结合SSR、EST标记筛选与抗条锈病基因紧密连锁的的分子标记，构建遗传图谱，进行抗病基因定位，阐明抗病机制。本研究结果将为抗病基因资源合理布局和小麦抗条锈病遗传改良提供科学依据。

条锈病是严重影响我国小麦生产的重要病害。兰天26是高抗小麦条锈病的优良品种，为了明确其携带的抗病基因，本项目以兰天26与高感条锈病品种铭贤169杂交构建分离群体，采用条锈菌CYR32、CYR33和混合菌系进行苗期接种和田间成株期抗病性鉴定。抗性遗传分析表明，兰天26在苗期和成株期对条锈菌的抗性均1对主效基因控制。利用（Bulked Segregant Exome Capture Sequencing,BSE-Seq）技术分析确定苗期抗病基因位于1BS染色体的95～96Mb区段，成株期抗病基因位于7BL染色体750Mb区段。根据候选区段的差异SNP和Indel开发分子标记，采用多态性标记对F2和F2:3代鉴定群进行检测验证。初步发现苗期抗病基因包含Yr9，成株期抗病基因不同于已知基因，暂命名为YrLT26。利用新开发的7个STS标记和已知的2个SSR标记，将YrLT26定位于7BL染色体臂GY17和Xcafa2040标记之间，与GY17共分离，与Xcafa2040遗传距离为0.6cM。结合小麦基因组序列信息，通过与7BL染色体上的其他已知抗条锈病基因连锁的分子标记进行比较，发现YrLT26是不同于7BL末端其他抗条锈病基因的新基因。苗期和成株期抗病基因聚合是兰天26对条锈菌表现出高抗至免疫的遗传基础。本研究结果将为分子标记辅助选择、加速培育优良小麦抗病新种质提供科技支撑。