基于CUBIC群体剖析玉米南方锈病抗性的遗传结构

玉米南方锈病是玉米生产上普遍发生的真菌性病害，解析病害抗性的遗传基础，分离主效抗病位点，对玉米抗病育种和解析抗病分子机制都有重要的意义。已有研究表明抗南方锈病的主效位点均集中在玉米第十号染色体短臂bin10.00/01上，然而在生产上该位点的抗性易丧失，因此需要鉴定新的抗病位点，并全面的解析南方锈病抗性的遗传结构。为此，本研究采用1404份家系构成的多亲本高世代互交群体（CUBIC），构建高密度的分子标记图谱，并完成多年多点的群体南方锈病抗性的鉴定。本研究拟通过关联分析在全基因组范围鉴定与抗性相关联的位点，剖析南方锈病抗性的遗传结构。本项目拟采用生物信息学和分子生物学等手段挖掘和验证2-3个主效抗病基因，并开发功能分子标记，筛选群体中高抗材料，分析抗病位点聚合特点，获得最佳的抗病位点聚合类型，为玉米抗病分子育种提供理论依据和实践指导。

Southern corn rust (SCR) is one of the devastating and widespread fungal diseases in corn production area. Genetic dissection of resistance to SCR and isolation of the resistance genes will play an importance role in understanding the mechanism of disease resistance and utilization in maize breeding program. It has been reported that all major QTLs resistance to SCR located in bin 10.00/01 at chromosome 10. However, the resistance of this locus has a tendency to lose in application process. It is necessary to identify new resistant loci and systematically dissect genetic architecture of resistance to SCR. Therefore, we used multiple inbred lines to developed a new genetic population, Complete-diallel plus Unbalanced Breeding-like Inter-Cross (CUBIC), which contained 1404 lines. This population were genotyped by high-density SNP markers and phenotyped in multiple environments. We will comprehensively dissect the genetic architecture of resistance to SCR by association analysis. Further, based on the detected QTLs, we will pick out 2-3 major QTLs to isolate the candidate genes and develop functional markers through bioinformatic analysis and molecular biological methods. This project plans to screen the high resistance lines and analyze the characteristics of pyramiding multiple resistant genes to obtain the best type of pyramiding genes, which provide practical guidance and lay a foundation for molecular breeding on maize disease resistance.