Average maize yield per hectare has increased significantly because of the improvement in high‐density tolerance, but little attention has been paid to the genetic mechanism of grain yield response to high planting density. Here, we used a population of 301 recombinant inbred lines (RILs) derived from the cross YE478 × 08–641 to detect quantitative trait loci (QTLs) for 16 yield‐related traits under two planting densities (57,000 and 114,000 plants per ha) across four environments. These yield‐related traits responded differently to high‐density stress. A total of 110 QTLs were observed for these traits: 33 QTLs only under low planting density, 50 QTLs under high planting density and 27 QTLs across both densities. Only two major QTLs, qCD6 and qWKEL2‐2, were identified across low‐ and high‐density treatments. Seven environmentally stable QTLs were also observed containing qED6, qWKEL3, qRN3‐3, qRN7‐2, qRN9‐2 and qRN10 across both densities, as well as qRN9‐1 under low density. In addition, 16 and eight pairs of loci with epistasis interaction (EPI) were detected under low and high planting densities, respectively. Additionally, nine and 17 loci showed QTL × environment interaction (QEI) under low‐ and high‐density conditions, respectively. These interactions are of lesser importance than the main QTL effects. We also observed 26 pleiotropic QTL clusters, and the hotspot region 3.08 concentrated nine QTLs, suggesting its great importance for maize yield. These findings suggested that multiple minor QTLs, loci with EPI and QEI, pleiotropy and the complex network of “crosstalk” among them for yield‐related traits were greatly influenced by plant density, which increases our understanding of the genetic mechanism of yield‐related traits for high‐density tolerance.

中文翻译：

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玉米低密度和高密度下产量相关性状的数量性状基因座图谱

由于高密度耐性的提高，每公顷玉米平均单产显着提高，但对高密度种植的谷物产量响应的遗传机制却很少受到关注。在这里，我们使用了由YE478×08–641杂交得到的301个重组自交系（RIL）种群，在两个种植密度下（每公顷57,000和114,000株），检测了16个产量相关性状的数量性状基因座（QTL）。四个环境。这些与产量相关的性状对高密度胁迫的反应不同。这些性状共观察到110个QTL：仅在低种植密度下有33个QTL，在高种植密度下有50个QTL，在两种密度下都有27个QTL。仅两个主要QTL，qCD6和qWKEL2-2在低密度和高密度处理中均被确定。还观察到七个环境稳定的QTL，包括两个密度的qED6，qWKEL3，qRN3-3，qRN7-2，qRN9-2和qRN10以及qRN9-1在低密度下。此外，分别在低种植密度和高种植密度下检测到16对和8对具有上位互作的位点。此外，在低密度和高密度条件下，分别有9个和17个基因座表现出QTL×环境相互作用（QEI）。这些相互作用的重要性不及主要QTL效应。我们还观察到26个多效QTL簇，而热点区域3.08集中了9个QTL，表明其对玉米产量非常重要。这些发现表明，与产量相关性状的多个次要QTL，与EPI和QEI的位点，多效性和复杂的“串扰”网络都受到植物密度的影响，这加深了我们对产量相关性状遗传机制的理解。高密度公差。