试验以陕单609、榆玉3号、先玉335、郑单958、秋润100、陕单636为供试品种，在67 500株/hm²和82 500株/hm²两种种植密度下，研究增密对不同玉米品种子粒产量和营养品质的影响。结果表明，随着密度的增加，子粒产量、收获穗数、群体干重和LAI显著增加，穗粒数、百粒重和子粒蛋白质含量呈下降趋势，淀粉含量和粗脂肪含量不同品种间呈现不规律变化。密植条件下，品种间子粒产量差异更为明显，陕单609、先玉335和榆玉3号的产量显著高于其他品种，分别较郑单958增产1.98%、11.26%和2.37%。陕单636增密后影响产量的主要因素是粒重，先玉335和郑单958增密后影响产量的主要因素是穗粒数，陕单609、榆玉3号和秋润100增密后影响产量的因素是穗粒数和粒重。因此，选择优良品种，适当增加玉米种植密度，加强田间管理，保证穗粒数和粒重稳定，是实现玉米密植高产优质的重要途径。

In order to investigate the influence of planting density on grain yield and quality traits of different maize varieties, six varieties (Shandan609, Yuyu 3, Xianyu335, Zhengdan958, Qiurun100 and Shandan636) were selected and planted in two densities (67 500 and 82 500 plants/ha). The results indicated that grain yield increase significantly with the addition of plant density, so did the number of panicles, the LAI, and the above-ground dry material accumulation, while the 100-kernels weight and protein content of the grain showed a downward trend, the starch content and crude fat content showed irregular changes among different varieties. The difference in grain yield between varieties was more pronounced under high density, the yields of Shandan609, Xianyu335, and Yuyu 3 were significantly higher than other varieties, and they increased by 1.98%, 11.26%, and 2.37%, respectively, compared with Zhengdan 958. With the addition of the plant density, the main factor affecting yield of Shandan636 was grain weight, the main factor affecting the yield of Xianyu335 and Zhengdan958 was the number of grains per ear, while the factors that affect the yield of Shandan609, Yuyu 3 and Qiurun100 were grain number and grain weight. Therefore, selecting excellent varieties, increasing planting density appropriately, and strengthening field management are important ways to achieve high yield and quality of maize.

S513.047

国家自然科学基金项目（31771724）、陕西省科技攻关项目（2018NY-031）