施氮对夏玉米碳氮代谢及穗粒形成的影响  

Effect of nitrogen supply on carbon-nitrogen metabolism and kernel set in summer maize

作　　者：申丽霞[1] 王璞[2] 兰林旺[2] 孙西欢[1] 

机构地区：[1]太原理工大学水利科学与工程学院,山西太原030024 [2]中国农业大学农学与生物技术学院,北京100094

出　　处：《植物营养与肥料学报》2007年第6期1074-1079,共6页Journal of Plant Nutrition and Fertilizers

基　　金：国家高技术研究发展计划(863计划)节水重大专项资助

摘　　要：以夏玉米杂交种郑单958为材料,对不同施氮水平下玉米产量、产量构成、粒数形成关键期植株体的碳氮代谢及碳氮代谢的关键酶进行了研究。结果表明,氮肥对玉米产量的影响主要体现在对穗粒数、穗粒重的影响上。施氮量为180 kg/hm2时,显著促进玉米穗粒数、穗粒重的增加;施氮量增加至240 kg/hm2时,促进作用下降。施氮明显促进大喇叭口期至灌浆期植株体的碳氮代谢,使碳氮代谢的关键酶硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和蔗糖磷酸合成酶(SPS)活性提高,增强光合产物的积累和运输,从而满足生殖生长的需求,促进穗粒数的形成,提高产量。在抽丝前供氮充足的前提下,抽丝期施氮对增产意义不大。Kernel number was the main factor affecting maize yield. Nitrogen supply affected carbon-nitrogen （C-N） metabolism in maize, then affected kernel number and yield. The objectives of this work were： 1 ） to evaluate the effect of nitrogen on yield and its components, and to determine the relationship between yield and kernel number; 2）to analyze C - N metabolism in maize, and explore the possible reasons affecting kernel set. A field experiment with summer maize （Zea mays L. ） hybrid Zhengdan 958 was carried out at Wuqiao experiment station of China Agricultural University in 2004. The plant density was 67500 plant/ha. Four basic nitrogen rates （0, 120, 180, 240 kg/ha） and two top dressing rates （240,300 kg/ha） in silk stage were set up. Grain yield and its components, the content of soluble sugar and nitrogen, the main enzymes that affected C - N metabolism such as nitrate reductase （NR）, grutamine synthetase （GS）, and sucrose phosphate synthetase （SPS） in maize were studied. The results showed that nitrogen affected maize yield mainly through affecting kernel number. Nitrogen supply could evidently improve the activities of enzymes NR, GS, and SPS in ear leaves, accelerate C - N metabolism during kernel set stage, promote assimilate accumulation and distribution, and increase kernel number and yield. The results suggested that the nitrogen supply rate 180 kg/ha showed the best result on kernel number and yield in maize, while the nitrogen supply rate 240 kg/ha had negative effect. Under the prerequisite of nitrogen adequate supplied before silk stage, top dressing nitrogen in silk stage had negligible effects on yield.

关 键 词：玉米 氮肥 碳氮代谢 产量 穗粒数 

分 类 号：S513[农业科学—作物学]