基于NAM群体的油菜产量及产量相关性状的联合连锁分析和全基因组关联分析

Crop yield and yield-related traits are mainly complex quantitative traits. Two strategies, genetic analysis based on bi-parental segregation populations and genome-wide association studies (GWAS) based on natural populations, are usually used to dissect the genetic bases of quantitative traits. Each strategy has its own advantages and disadvantages. Nested-association mapping (NAM) population derived from the cross of multiple parents not only has advantages of both bi-parental segregation population and natural population, but also overcomes their disadvantages. NAM population has been widely used to dissect the genetic bases of complex quantitative traits in maize. We selected the sequencing variety Zhongshuang 11 as the common parent and crossed to 15 representative diverse varieties. Recombinant inbred lines (RIL) were developed for each family by single seed descent, which comprised of the NAM population. In this study, we are planning to grow the NAM population and investigate the yield and yield-related traits in multiple locations and multiple years, genotype the population using genotyping-by-sequencing, and construct high-density genetic linkage maps for all RIL populations. We are going to dissect the genetic bases of the yield and yield-related traits using joint-linkage analysis and GWAS in order to identify the key genes controlling these traits and their underlying variations. We expect to decipher the functions of the target genes and reveal the underlying molecular mechanism of rapeseed yield and yield-related traits. We also expect that these results would be the foundation for the genetic improvement of yield and yield-related traits in oilseed rape.

作物的产量及产量相关性状是复杂的数量性状，解析数量性状的遗传基础有两种方法：基于双亲本分离群体的连锁分析和基于自然群体的全基因组关联分析，这两种方法各有优缺点。基于多亲本杂交的巢式关联分析（NAM）群体兼具双亲本分离群体和自然群体的优点，又克服了两种群体的不足，已广泛应用于玉米复杂数量性状的遗传基础解析。我们以油菜测序品种“中双11”为共同亲本，与具有广泛代表性的15个自交系分别杂交，经连续自交构建了由15个RIL群体组成、共2425个家系的NAM群体。本研究中，我们拟多年多点种植NAM群体，考察产量及产量相关性状，同时用简化基因组测序法分别构建各群体高密度遗传连锁图，并用联合连锁分析和全基因组关联分析相结合的策略解析油菜产量及产量相关性状的遗传基础，鉴定控制这些性状的关键基因及其遗传变异，深入研究基因功能，揭示油菜产量及产量相关性状形成的分子机理，为油菜品种遗传改良提供理论基础。

作物的产量及产量相关性状是复杂的数量性状，巢式关联分析（NAM）群体兼具双亲本分离群体和自然群体的优点，在玉米等作物中已广泛应用于复杂数量性状的遗传基础解析。本项目以油菜测序品种“中双11”为共同亲本、包含15个重组自交系RILs的油菜NAM群体为研究材料，通过简化基因组测序法进行基因分型并分别构建各群体高密度遗传连锁图，揭示了油菜NAM群体的群体结构、LD衰减等群体参数。考察了三年五点的产量和产量相关性状，结合联合连锁分析和全基因组关联分析的策略解析了油菜产量及产量相关性状的遗传基础，鉴定了100多个控制这些性状的关键基因和遗传变异，初步揭示了开花期、角果长和千粒重、株高等部分产量相关性状形成的分子机理，为油菜品种遗传改良提供目标基因和分子标记。