芝麻含油量及脂肪酸含量QTL分析

本研究以较高含油量芝麻品种“中芝13”（56.31%）和低含油量芝麻材料ZZM2748（48.75%）为亲本构建包含548个株系的RIL群体，采用近红外法对群体在2个不同环境下的含油量、油酸、亚油酸、棕榈酸和硬脂酸含量进行分析，发现群体含油量及脂肪酸含量存在较大变异，其中含油量变化在42.43%~58.38%，其与油酸和亚油酸含量无显著相关关系，但与棕榈酸显著负相关；应用软件WinQTLCart2.5和ICIMapping3.0基于构建的遗传连锁图共定位到50个相关QTL，分布在芝麻11个连锁群上，贡献率变化在1.59%~40.62%。其中，有21个QTL被两个软件同时检测到，有7个QTL在2个环境下被重复检测到。位于连锁群LG10上的qSOC_10.3和位于连锁群LG11上的qSOC_11.1遗传贡献率较大，分别为34.38%和40.62%，为控制芝麻含油量的主效QTL，其中qSOC_11.1与定位到的油酸、亚油酸、棕榈酸和硬脂酸位点重合，表现一因多效特征。通过基因组注释和差异表达分析，在两个主效位点发掘出24个候选基因。研究发现的芝麻含油量及不同脂肪酸含量遗传变异特征和获得的QTL及候选基因对相关性状的遗传改良具有指导意义和应用价值。

Quantitative trait locus analysis for sesame oil and fatty acid contents

In this study, the oil content, oleic acid, linoleic acid, palmitic acid and stearic acid content variations of the RIL population, that generated from the high oil content sesame cultivar "Zhongzhi 13" (56.31%) and the low oil content sesame material ZZM2748 (48.75%) with 548 lines, were studied in two different environments by near infrared method, and the QTL were mapped using the two softwares WinQTLCart2.5 and ICIMapping3.0 based on a genetic linkage map. It was found that the oil content and fatty acid content of the population had great variation. The RIL oil contents varied from 42.43% to 58.38% in different environments, and it had no significant correlation with oleic acid and linoleic acid content but palmitic acid content. A total of 50 QTLs were mapped and distributed in 11 linkage groups of sesame, with the contribution rate varying from 1.59% to 40.62%. Among them, 21 QTLs were detected by the two software parallelly, and 7 QTL were repeatedly detected in the two environment. The two QTL qSOC_10.3 and qSOC_11.1contributed 34.38% and 40.62% to the phenotype variations respectively, and were the major loci for the oil content variation. Especially, qSOC_11.1 also exhibited pleiotropic for oleic acid, linoleic acid, palmitic acid and stearic acid. In combination with gene annotation and differential expression analysis, 24 candidate genes were found at the two major loci. The genetic variation characteristics of sesame oil content and different fatty acid content, QTL and candidate genes obtained in this study have guiding significance and application value for genetic improvement of related traits.