基于多性状联合分析的甜高粱抗倒伏性状相关优异等位变异挖掘

Sweet sorghum (Sorghum bicolor (L.) Moench) is a crop that can be grown in the harsh natural conditions, it has wide range of uses, and has broad prospects for development in the Xinjiang region. Lodging is one of the main limitations for its high yield and stable yield. The identification and utilization of lodging resistance germplasm and the excellent gene carried in them were the main focuses on the sweet sorghum breeding in the future. In this study, five hundreds of domestic and foreign Sweet Sorghum Germplasms were the research object, the traits related to lodging resistance were accurately appraisaly in field, and The SSR molecular marker were designed used published sequenced varieties of whole genomic sequence, and then be used to genotype of the SSR molecular markers of Sweet Sorghum Germplasms; The full rank allele encoding method was used to construct allelic main effects of each locus, interaction effects of non alleles in the design matrix, phenotypic traits matrix was constructed using traits related to the lodging resistance as a whole . The scaning in sweet sorghum genome genome was performed using super-saturation models with multiple traits to identify important loci, and then allelic effects, non allelic interaction effects were estimated, ultimately the carrier of superior allelesl related to odging resistance were detected .This study is expected to lay a foundation for the molecular breeding of sweet sorghum lodging resistance.

甜高粱(Sorghum bicolor (L.) Moench)是一种可在恶劣自然条件下生长的作物，具有广泛用途，在新疆地区具有广阔的发展前景。倒伏是限制其高产、稳产的主要影响因素之一。抗倒伏种质鉴定及其携带优异等位基因的识别及利用是今后甜高粱遗传育种的主要研究方向。本研究拟以500份国内外甜高粱种质资源为研究对象，田间对其抗倒伏相关性状进行准确评价，利用公开发表及测序品种基因组序列设计SSR引物，对甜高粱种质资源进行分子标记的分型。以满秩的等位基因编码方法构建各座位等位基因主效应、非等位基因互作效应的设计矩阵，以各抗倒伏相关性状构建表型性状矩阵。应用本研究提出的多性状超饱和模型对甜高粱基因组进行基因组扫描，识别重要基因座位，并对各座位等位基因效应、非等位基因间的互作效应进行估计，最终识别优异抗倒伏等位基因载体材料，以期为甜高粱的抗倒伏分子育种奠定基础。

项目背景：倒伏影响作物的产量和品质，亦严重限制机械化作业，对于甜高粱尤其如此。对国家种质资源库中的甜高粱品种蕴含的抗倒伏品种的鉴定和抗倒伏基因的挖掘利用是我国种质资源工作的内容之一。本研究通过高密度的全基因组SNP标记和抗倒伏相关性状的表型数据，进行性状-标记关联研究，准确识别了一批与甜高粱抗倒伏相关的QTN，基于此，后续可根据该结果对其它甜高粱品种的抗倒伏性进行标记辅助选择，加快抗倒伏种质鉴定的准确性和稳定性，加快育种进程。.主要研究内容：①对401份国内外甜高粱种质抗倒伏相关性状（茎秆基部的抗压力、抗折力、抗穿刺力等）的表型分布进行研究。②对甜高粱抗倒伏相关的表型性状进行相关关系研究。③基于全基因组测序SNP的401份甜高粱种质的群体结构研究。④使用R中rMVP软件包的三种关联分析方法（GLM、MIM、FarmCPU）分别对抗倒伏相关性状如抗压力、抗折力、抗穿刺力、茎粗、基部1-4节长度和倒伏系数等进行全基因组关联分析。.重要结果：①获得了抗倒伏相关性状的表型分布。②获得了401份甜高粱基因型数据的主成分分析结果。③得到了标记密度全基因组分布结果。④获得了茎秆抗压力、抗折力、抗穿刺力、茎粗、基部1-4节长度和倒伏系数等相关性状全基因组关联分析结果，确定了一批显著的SNP标记，即QTNs，获得了包含标记所在的染色体、物理位置、P值，加性效应a、表型贡献率等关键数据。.关键数据：①401份甜高粱表型性状（抗压力、抗折力、抗穿刺力、穗粒重、株高、重心高度、茎粗、汁重、穗柄粗、茎秆鲜重、穗柄长、穗长、穗重、出汁率和锤度等性状）的测定数据。②401份甜高粱种质基于全基因组测序的SNP基因型数据。③全基因组关联分析结果中与甜高粱抗倒伏相关的显著的QTNs数据。.科学意义：.本项目通过性状-标记关联研究而准确识别到的一批与甜高粱抗倒伏相关的QTNs，可为甜高粱品种的倒伏性进行标记辅助选择提供依据，对于快速鉴定倒伏性加快育种进程，提高育种的预见性具有重要价值。