施氮对夏玉米顶部籽粒早期发育及产量的影响

以夏玉米杂交种郑单958为材料，对不同施氮水平下顶部籽粒的早期发育状况及产量进行了研究。结果表明，施氮明显促进关键酶活性的增强，促进顶部籽粒的早期发育。当施氮量为180 kg/hm²时，顶部籽粒的酸性蔗糖转化酶（AI）、中性蔗糖转化酶（NI）、蔗糖合成酶（SS）、腺苷二磷酸葡萄糖焦磷酸化酶（ADPGase）、淀粉

Effect of Nitrogen Supply on Early Kernel Development and Yield in Summer Maize (Zea mays L.)

Maize grain yield is closely associated with kernel number at maturity,and kernel number is affected by apical kernel abortion mainly occurred at early kernel filling stage.Improving apical kernel development and reducing apical kernel abortion can contribute to increment of kernels per ear.The objectives of this work were to evaluate the effect of nitrogen supply on early kernel development and grain yield in maize.In field condition,early development of apical kernel in summer maize hybrid Zhengdan 958 and its grain yield under different nitrogen supplies(0,120,180 and 240 kg/ha) and the activities of enzymes related to kernel development such as acid sucrose invertase(AI),neutral sucrose invertase (NI),sucrose synthase(SS),ADPGase and starch synthase were determined.The results showed that suitable nitrogen supply obviously increased the activities of enzymes above and promoted apical kernel development.At 520 days after pollination(DAP),higher activities of AI,NI,SS,ADPGase and starch synthase in apical kernel were obtained under nitrogen supply of 180 kg/ha,indicating the sucrose utilization and starch synthesis were improved.The fresh weight,size,dry weigh,the contents of soluble sugar,nitrogen and starch in apical kernel in 520 DAP were higher under nitrogen supply of 180 kg/ha than under other nitrogen rates.With increasing supply of nitrogen ranging from 0 to 180 kg/ha,the kernel development were promoted and the kernel abortion were reduced which resulted in more kernels per ear and higher yield.Nitrogen deficiency or excessiveness affected apical kernel development,which resulted in higher kernel abortion and lower grain yield.