灌浆初期低温对春玉米产量构成的影响研究

旨在研究东北地区低温冷害对春玉米灌浆的影响,确定春玉米灌浆期间冷害影响农业气象指标。用人工气候室通过模拟自然低温（平均15℃、17℃、19℃）方法,对灌浆初期盆栽春玉米进行（3、5、7天）胁迫处理。结果表明：春玉米在灌浆初期经不同天数的低温处理后,穗粒数减少,穗粒重、百粒重和叶绿素降低,成熟期延迟,果穗秃尖长度和籽粒含水量增加,作物产量呈不同程度的下降。温度越低,持续时间越长,对玉米产量的影响越严重。其中在15℃低温下处理7天后,玉米产量下降最大,较对照穗粒重减少了32.4%,百粒重减少9.2%。可见,灌浆初期低温对春玉米产量结构影响最大的因素是结实率和籽粒干物质含量的双重降低。

Low Temperature in Early Grain Filling Period of Spring Maize: Effect on Yield Components

This study aims at studying the effect of low temperature injury on grain filling of spring maize and determining the agro-meteorological indexes of low temperature injury in the grain filling period in northeast China. Pot planted spring maize was subjected to different levels of low temperature (mean 15℃, 17℃ and 19℃) in early grain filling period for 3, 5 and 7 days in the artificial climate chamber. The results showed that low temperature treatments decreased the number of kernels per ear, the kernel weight per ear, 100-kernel weight and the chlorophyll content, postponed the maturing period and increased the length of ear bald tip and the water content of kernels. As a result, the yield was decreased in various degrees. The lower the temperature and the longer the duration of low temperature, the higher the yield reduction of maize was. The yield of maize decreased the most under the treatment of 7 days at 15℃ among all the treatments, and compared with the control treatment, the kernel weight per ear was reduced by 32.4% and the 100-kernel weight was reduced by 9.2%. Therefore, low temperature in the early kernel filling period could result in the double reduction of kernel setting rate and kernel dry matter content, which is the most important factor affecting the yield components of spring maize.