油菜籽半必需氨基酸含量的种子胚和母体植株QTL定位与分析

QTL Mapping and Analysis Based on Embryo and Maternal Genetic Systems for Semi-Essential Amino Acid Contents in Rapeseed(Brassica napus L.)

菜籽饼是重要的饲料蛋白质来源,氨基酸组成与饲料营养品质有着密切关系,其中丝氨酸、胱氨酸和酪氨酸为多数动物的半必需氨基酸。本研究利用甘蓝型油菜双单倍体(DH)群体分别与双亲Tapidor和Ningyou 7回交构建的2套BC1F1群体,采用新创建的双子叶作物种子品质性状遗传体系QTL定位软件和作图方法,对油菜籽丝氨酸、胱氨酸和酪氨酸含量进行了种子胚和母体植株2套遗传体系的QTL定位分析。结果表明,在A1、A4、A7、A8、A9、C2、C3和C9染色体上检测到5个丝氨酸含量QTL、2个胱氨酸含量QTL和5个酪氨酸含量QTL,分别解释59.34%、29.66%和59.26%的表型变异。其中5个QTL属于主效QTL,均能解释10%以上的表型变异。全部QTL均具极显著的胚和母体加性主效应,其中3个QTL具显著或极显著的环境互作效应。在A4染色体上发现1个QTL簇,该区域存在3个控制丝氨酸、胱氨酸和酪氨酸含量的QTL。一些重要QTL以及与之紧密连锁的分子标记在今后图位克隆和分子标记辅助选择育种中具有重要的利用价值。

Rapeseed meal is an important feed protein source, and the amino acid composition has a close relationship with the processing quality of feed, of which serine, cystine and tyrosine are the semi-essential amino acids for most animals. By using newly developed two-genetic-system QTL mapping software and method for analyzing seed quality traits of dicotyledonous plants, two backcross populations from a set of doubled haploid（DH） lines derived from an elite hybrid cross between Tapidor and Ningyou 7 were used to detect the QTLs simultaneously located in the amphidiploid embryo and maternal plant nuclear genomes for the semi-essential amino acid contents of rapeseed across environments. The results showed that five QTLs for serine content, two QTLs for cystine content and five QTLs for tyrosine content were identified, which were subsequently mapped on chromosomes A1, A4, A7, A8, A9, C2, C3, or C9 and could respectively explain 59.34%, 29.66%, and 59.26% of phenotypic variation in total. Five QTLs were major effect QTLs which could explain more than 10% of phenotypic variation for each. All of these QTLs had both notable embryo and maternal additive main effects, among which three QTLs were also found to have significant QE interaction effects. One QTL cluster on chromosome A4 was discovered to contain three QTLs related to serine, cystine and tyrosine contents. Some important QTLs and the tightly linked markers will have an important application value in the later map-based cloning and marker-assisted selection.