以华北地区主栽的8个玉米杂交种和中国农业大学自育的2个杂交组合为试验材料，在不同供氮水平（0、240 kg/hm²）下对玉米子粒产量及其构成因素和根拔拉力进行研究。结果表明，百粒重在不同氮处理间差异显著，平均产量、穗粒数及根拔拉力差异极显著，穗长、穗粗及穗行数没有显著差异。不同玉米基因型产量下降的主要原因是穗粒数的降低。低氮处理下根拔拉力显著降低，其降低幅度与产量的减产幅度显著相关，可作为氮高效品种筛选的指标之一。

The relationship between yield and root-pulling resistance were investigated at two nitrogen levels(0 and 240 kg/ha) by using 8 commercial maize hybrids and 2 unreleased hybrids. The results showed that there were significant decreases for both vertical root-pulling resistance and yield under lower nitrogen supply. Yield decrease was mainly resulted from the reduction of kernel number. Furthermore, a significant positive correlation for the falling range between vertical root-pulling resistance and yield was further observed, which might be used as one of the indicators for screening nitrogen efficient varieties.

公益性行业科研专项（200803030）