大豆种子维生素E含量的QTL和eQTL分析及精细定位研究

Soybeans are the important oil crops and food crops. The soybeans have abundant contents of vitamin E. Soybeans are the main resource of vitamin E. The natural vitamin E has the high market value. But people can’t synthesize it themselves. The vitamin E is obtained mainly from the plants. At present the contents of the vitamin E in the soybean varieties cannot satisfy the people’s need.In this study, genetic linkage map including 4407 SNP markers was constructed by simplified genome sequencing derived from a cross between Bayfield and Hefeng25 and 144 RILs. QTLs of vitamin E metabolism were obtained. Analysis the eQTL of five key genes in the vitamin E synthesis and find the hot regions of vitamin E in regulating metabolism of related gene expression in soybean. Clarify its is cis or trans regulation regulation. SNP markers and target gene regions associated with vitamin E could be obtained. Fine mapping of residual heterozygous lines was obtained combining with 28 QTLs and coseparation markers were obtained. The eQTL of five genes related with metabolism of vitamin E were obtained. And the new soybean germplasm with high content of vitamin E was obtained by the molecular marker assisted selection. The main effect QTL was defined by eQTL analysis and obtaining 28 QTL. The cosegregating markers and functional molecular markers were obtained by fine mapping of the major QTL using SNP marker screening residual heterozygous line. The new soybean germplasm of high vitamin E content was obtained by molecular marker assisted breeding.

大豆是重要的油料作物和粮食作物，大豆中富含维生素E，是天然维生素E的主要来源。天然维生素E具有较高的市场价值，人类自身无法合成，主要从植物中摄取。目前，现有的大豆品种中的维生素E含量远远不能满足人们的日常需求。本项目以“合丰25”和“OAC Bayfield”杂交衍生的重组自交系作为群体，利用简化基因组测序，构建包含4407个SNP标记的遗传连锁图谱，定位与维生素E代谢相关的QTL，对维生素E合成相关的关键基因进行eQTL分析，找到调节大豆维生素E代谢相关基因表达的热点区，并阐明是顺式还是反式调控。结合前期获得的28个QTL，以及eQTL分析结果，定义出稳定的主效QTL。利用SNP标记筛选剩余杂合系，对主效QTL进行精细定位，获得共分离标记和功能性分子标记，进而通过分子标记辅助育种准确选择出高维生素E含量的大豆新种质。

天然维生素E具有较高的市场价值，人类自身无法合成，主要从植物中摄取。大豆是重要的油料作物和粮食作物，大豆中富含维生素E，是天然维生素E的主要来源。本研究以155份大豆种质资源、144份重组自交系和剩余杂合系群体为试验材料，利用高效液相色谱检测大豆籽粒中总维生素E及其各组分含量，对总维生素E与α-、γ-、δ-生育酚之间以及α-、γ-、δ-生育酚之间的相关性进行分析，并对其进行变异分析以评价大豆维生素E及组分的稳定性。另外，利用全基因组的36981个单核苷酸多态性SNP，结合155份大豆种质资源的表型数据，通过混合线性模型进行关联分析。同时，对合丰25和Bayfield杂交衍生的144份重组自交系群体和剩余杂合系进行遗传图谱的加密，定位了维生素E含量及其组分含量相关QTL，同时对维生素E合成过程中关键基因的表达模式进行分析，利用复合区间作图法进行eQTL分析，定位与维生素E合成相关的eQTL位点，对大豆种质资源维生素E含量及各组分含量的全基因组进行关联，共定位到190个显著关联的QTN，对重组自交系群体的eQTL中共定位出7个eQTL，与MPBQ-MT基因转录丰度相关的eQTL有2个，与HPT基因转录丰度相关的eQTL有5个，与2个及2个以上性状同时相关的位点有1个；全基因组关联分析、QTL以及eQTL重叠的区域内共定位出8个候选基因，并在F7世代决选出4个高维生素E大豆新种质。为培育高维生素E的大豆新品种做了很好铺垫。