对河南省 1988～ 2 0 0 0年早熟组夏玉米区试中不同产量水平下玉米杂交种主要农艺性状变化 ,以及对 72 15kg/hm2 以上产量水平进行相关及通径分析 ,结果表明 :选育 75 2 0kg/hm2 以下玉米杂交种时 ,必须重视千粒重、穗长和行粒数的选择 ;选育 75 2 0kg/hm2 以上玉米杂交种时 ,应在稳定提高穗粗和穗行数基础上 ,主攻千粒重、穗长和行粒数 ,同时注意生育期和株高要适中 ,把杂交种的各农艺性状协调到最佳程度 ,选育出性状优良的高产杂交种 The main agronomic traits of maize hybrids under different yield levels in 1988 ~ 2000 early maturing summer maize regional trial and correlation analysis and path analysis of yield above 72 15kg / hm2 showed that: breeding 75 2 0kg / hm2 maize hybrids, we must attach importance to the 1000-grain weight, spike length and row grain number selection; breeding more than 75 2 0kg / hm2 above maize hybrids should be based on the stable increase ear diameter and ear number, The main attack grain weight, spike length and grain number, pay attention to the growth period and plant height should be moderate, the agronomic traits of hybrids coordinated to the best level, bred high-yielding hybrids with good traits