低氮胁迫对不同基因型夏玉米源库性状和灌浆特性的影响

2007和2008年连续2年在低氮（105 kg·hm^-2）和正常施氮（337.5 kg·hm^-2）两种施肥水平下，分析了6个不同基因型玉米品种的群体源库关系及籽粒灌浆特性间的差异.结果表明：低氮胁迫对不同基因型玉米品种的群体产量、叶面积指数（LAI）、群体源库性状和籽粒灌浆特性影响明显，在低氮胁迫下，先玉335、郑单958等耐低氮能力较好品种的籽粒活跃灌浆期较长、最大灌浆速率高、最大叶面积指数持续期较长，群体库源关系比较协调；陕单902和豫玉22等耐低氮能力较差品种吐丝后的籽粒活跃灌浆时数、最大灌浆速率、灌浆速率最大时的生长量及LAI较低，源的供应能力显著下降；低氮胁迫明显加剧了不同基因型玉米品种间的产量差异.

Effects of low nitrogen stress on source-sink characters and grain-filling traits of different genotypes summer maize

This paper studied the source-sink characters and grain-filling traits of six genotype summer maize varieties under 2 years (from 2007 to 2008) application of low dosage (105 kg·hm^-2) and normal dosage (337.5 kg·hm^-2) fertilizer nitrogen. Under low nitrogen stress, the population yield, leaf area index (LAI), source sink characters, and grain-filling traits of test varieties differed significantly. The varieties tolerant to low nitrogen, e.g., Xianyu 335 and Zhengdan 958, had longer active grain-filling stage, higher maximum filling rate, longer duration of maximum LAI, and more harmonious sink-source relation; while less tolerant species,e.g., Shaandan 902 and Yuyu 22, had shorter active grain-filling hours, lower maximum filling rate, lower mass increment and LAI under maximum grain-filling rate after silking, and significantly decreased source supply capacity. Low nitrogen stress increased the yield difference among the test varieties significantly.