摘要： 为明确不同种植密度下玉米品种各生育时期群体叶面积指数（LAI）和籽粒灌浆之间的关系，揭示不同密度对群体LAI和灌浆特性的调控机制。选用冀中南地区3个高产玉米品种，研究了6种种植密度对不同生育时期群体LAI和灌浆特性的影响。结果表明：3个品种LAI在整个生育期内均呈先升高后下降的趋势，在吐丝期达到顶峰，吐丝期以后开始下降。3个品种各生育时期LAI均随密度的增加而升高，在相同的密度水平下，衡玉1182群体LAI要大于郑单958和先玉335，表现出较强的耐密性。玉米产量与LAI呈二次函数关系，郑单958、先玉335和衡玉1182最适LAI分别为3.252，3.193，4.125。3个品种吐丝期最大LAI与种植密度均呈极显著相关，最大LAI随密度增加而直线增加。3个品种玉米籽粒的百粒质量均随灌浆进程呈现出慢-快-慢"S"形变化，各品种籽粒灌浆速率在整个籽粒发育过程中呈单峰抛物线型变化，最大灌浆速率出现在授粉后30 d左右，不同品种各处理最大灌浆速率均表现为低密度 > 中密度 > 高密度，且低密度籽粒灌浆速率要高于中、高密度。在达到最大灌浆速率后，衡玉1182灌浆速率下降速度要快于郑单958和先玉335。各密度下群体籽粒灌浆过程均可用Logistic方程模拟，将各品种灌浆过程划分为粒重渐增期、线性灌浆期和缓增期，相同密度水平下，衡玉1182籽粒灌浆速率最高峰值（G_max）和籽粒灌浆速率平均值（G_mean）要大于郑单958和先玉335，活跃灌浆期（D）则小于郑单958和先玉335，3个品种不同灌浆时期平均灌浆速率表现为衡玉1182 > 先玉335 > 郑单958。3个品种随着种植密度的增加，穗长、穗粗、行粒数、穗行数和千粒质量均表现下降的趋势，秃尖呈现上升的趋势。衡玉1182是在82 500株/hm²时达到了产量的最大值，郑单958和先玉335种植密度是75 000株/hm²时产量最大，最大产量3个品种表现为衡玉1182 > 先玉335 > 郑单958。

关键词: 密度, 玉米, LAI, 灌浆特性

Abstract: Identifying the relationship between the leaf area index (LAI) and grain filling in different growth stages of new maize hybrids under different planting densities and to reveal the regulation mechanism of different density on population LAI and grain filling characteristics.In this study,3 high-yield hybrids in the Middle and South Area of Hebei Province were used as experimental materials,the effects of 6 planting densities on LAI and grain filling characteristics in different growth stages were studied.The results indicated that 3 hybrids of LAI were first increased and then decreased in the whole growth period,reached its peak in the silking stage,then decreased gradually post-silk. The LAI with each stage of 3 varieties were increased with the density increasing,the LAI of Hengyu 1182 groups was higher than Zhengdan 958 and Xianyu 335 under the same planting density,the density tolerance showed strong. The LAI and grain yield showed a quadratic function,and the optimum LAI of Zhengdan 958,Xianyu 335 and Hengyu 1182 were,3.252,3.193 and 4.125 respectively.3 varieties of silking stage maximum LAI and planting density were significantly related,while maximum LAI increased linearly with the increased of density. The 100-kernel weight of 3 varieties showed a slow-fast-slow "S" shape change with the filling process,and the grain filling rate of varieties showed a single peak parabolic curve in the whole growth process,the maximum grain filling rate appeared at 30 d after pollination,the maximum grain filling rate of different varieties with different treatments showed that low density > medium density > high density,and the grain filling rate of low density was higher than medium density and high density.After reaching the maximum grain filling rate,the descent speed of grain filling rate of Hengyu 1182 was faster than Zhengdan 958 and Xianyu 335.The grain-filling processes of maize hybrids with different treatments were analyzed by Logistic model,and the total filling period could be divided into early stage,middle stage and late stage. The Logistic model showed that the peak grain filling rate (G_max) and the average grain-filling rate (G_mean) were higher in Hengyu 1182 whose active grain filling stage(D) was shorter than other 2 varieties,the average filling rate of 3 maize varieties in different filling stage showed that Hengyu 1182 > Xianyu 335 > Zhengdan 958. The ear length,ear diameter,grains per row,rows per ear,and 1000-grain weight decreased with the increased of planting density in 3 varieties,but the barren ear tips was just the opposite.The maximum yield of 3 maize varieties was different,Hengyu 1182 was in the 82 500 plant/ha to achieve the maximum yield,Zhengdan 958 and Xianyu 335 was 75 000 plant/ha,the maximum yield of 3 maize varieties showed that Hengyu 1182 > Xianyu 335 > Zhengdan 958.

Key words: Density, Maize, Leaf area index, Grain filling characteristic

中图分类号: 

• S513.01