Starch is a major component of cereals, comprising over 70% of dry weight. It serves as a primary carbon source for humans and animals. In addition, starch is an indispensable industrial raw material. While maize (Zea mays) is a key crop and the primary source of starch, the genetic basis for starch content in maize kernels remains poorly understood. In this study, using an enlarged panel, we conducted a genome-wide association study (GWAS) based on best linear unbiased prediction (BLUP) value for starch content of 261 inbred lines across three environments. Compared with previous study, we identified 14 additional significant quantitative trait loci (QTL), encompassed a total of 42 genes, and indicated that increased marker density contributes to improved statistical power. By integrating gene expression profiling, Gene Ontology (GO) enrichment and haplotype analysis, several potential target genes that may play a role in regulating starch content in maize kernels have been identified. Notably, we found that ZmAPC4, associated with the significant SNP chr4.S_175584318, which encodes a WD40 repeat-like superfamily protein and is highly expressed in maize endosperm, might be a crucial regulator of maize kernel starch synthesis. Out of the 261 inbred lines analyzed, they were categorized into four haplotypes. Remarkably, it was observed that the inbred lines harboring hap4 demonstrated the highest starch content compared to the other haplotypes. Additionally, as a significant achievement, we have developed molecular markers that effectively differentiate maize inbred lines based on their starch content. Overall, our study provides valuable insights into the genetic basis of starch content and the molecular markers can be useful in breeding programs aimed at developing maize varieties with high starch content, thereby improving breeding efficiency.

淀粉是谷物的主要成分，占干重的 70% 以上。它是人类和动物的主要碳源。此外，淀粉还是不可缺少的工业原料。虽然玉米 ( Zea mays ) 是一种重要作物和淀粉的主要来源，但人们对玉米粒中淀粉含量的遗传基础仍然知之甚少。在本研究中，我们使用扩大的面板，基于三个环境中 261 个自交系淀粉含量的最佳线性无偏预测 (BLUP) 值进行了全基因组关联研究 (GWAS)。与之前的研究相比，我们确定了 14 个额外的显着数量性状位点 (QTL)，总共包含 42 个基因，并表明标记密度的增加有助于提高统计功效。通过整合基因表达谱、基因本体（GO）富集和单倍型分析，已经鉴定出可能在调节玉米籽粒淀粉含量中发挥作用的几个潜在靶基因。值得注意的是，我们发现ZmAPC4与重要的 SNP chr4.S_175584318 相关，该 SNP chr4.S_175584318 编码 WD40 重复超家族蛋白，并在玉米胚乳中高表达，可能是玉米籽粒淀粉合成的关键调节因子。在分析的 261 个近交系中，它们被分为四种单倍型。值得注意的是，据观察，与其他单倍型相比，携带 hap4 的自交系表现出最高的淀粉含量。此外，作为一项重大成就，我们开发了分子标记，可以根据淀粉含量有效区分玉米自交系。总的来说，我们的研究为淀粉含量的遗传基础提供了有价值的见解，分子标记可用于旨在开发高淀粉含量玉米品种的育种计划，从而提高育种效率。