Genome-wide association study dissects the genetic architecture of oil biosynthesis in maize kernels

Maize kernel oil is a valuable source of nutrition. Here we extensively examine the genetic architecture of maize oil biosynthesis in a genome-wide association study using 1.03 million SNPs characterized in 368 maize inbred lines, including 'high-oil' lines. We identified 74 loci significantly associated with kernel oil concentration and fatty acid composition (P < 1.8 x 10(-6)), which we subsequently examined using expression quantitative trait loci (QTL) mapping, linkage mapping and coexpression analysis. More than half of the identified loci localized in mapped QTL intervals, and one-third of the candidate genes were annotated as enzymes in the oil metabolic pathway. The 26 loci associated with oil concentration could explain up to 83% of the phenotypic variation using a simple additive model. Our results provide insights into the genetic basis of oil biosynthesis in maize kernels and may facilitate marker-based breeding for oil quantity and quality.

玉米油是一种有价值的营养来源。在此，我们在一项全基因组关联研究中，对368个玉米自交系（包括“高油”系）中已鉴定的103万个单核苷酸多态性（SNP）进行了广泛研究，以探究玉米油生物合成的遗传结构。我们确定了74个与籽粒含油率以及脂肪酸组成显著相关的位点（P < 1.8×10⁻⁶），随后利用表达数量性状基因座（QTL）定位、连锁定位和共表达分析对其进行了研究。超过一半的已鉴定位点位于已定位的QTL区间内，并且三分之一的候选基因被注释为油脂代谢途径中的酶。利用一个简单的加性模型，与含油率相关的26个位点能够解释高达83%的表型变异。我们的研究结果为玉米油生物合成的遗传基础提供了见解，并可能促进基于标记的油脂数量和品质的育种。