中文摘要：

在池栽条件下，比较了不同供氮水平下玉米细胞质雄性不育系（CMS）及其同型可育系碳氮代谢的差异。结果表明，两种供氮水平下，CMS玉米子粒产量和收获指数均高于其同型可育系（P〈0．05），生物产量差异不显著（P〉0．05），根量较多，根／冠比高于其可育系（P〈0．05）。CMS玉米保绿性好，净同化率高，果穗叶光合速率生育后期优势明显。果穗叶硝酸还原酶（NRase）、谷氨酰胺合成酶（GS）和谷氨酸脱氢酶（GDH）活性均具有较高活性，两种供氮水平下都表现出相对优势；其叶片、茎秆和根中氮百分含量和氮积累量都表现出花后0～20d较高，生育后期较低的特点。CMS玉米的氮素转运多，贡献率和氮利用效率高，且不施氮水平下优势更为明显。说明雄性不育植株光合碳生产和果穗叶氮代谢能力强，促进了植株对氮素的转运和利用，有利于子粒灌浆充实和产量提高。

英文摘要：

Cytoplasmic male sterility （CMS） plays an important role in maize （Zea mays L. ） breeding for increasing yield and reducing costs. To investigate the effects of nitrogen rates after anthesis on carbon and nitrogen metabolism traits, we conducted a pool experiment by two nitrogen treatment in 2004-2005 with two inbred lines, cytoplasmic male sterility （478CMS and Qi319CMS） and homotype fertile lines（478 and Qi319）. The result showed that compared with their homotype lines （the maintainer lines）, CMS lines had higher grain yield and harvest index under two nitrogen levels （P 〈 0.05）, no significant difference existed in above-ground dry weight （P 〉 0.05）, maintained larger root amount and higher root/shoot ratio at nitrogen deficiency （ P 〈 0.05）. CMS lines had green-maintaining character and higher net assimilation rate, photosynthetic rate （Pn） of ear leave at late growth stage. Also, CMS lines maintained higher nitrate reductase （NR）, glutamate synthetase（GS）and glutamate dehydrogennase（GDH）activities of ear leaf under two nitrogen levels （ P 〈 0.05）. The nitrogen content and nitrogen assimilation amount of leave, stalk and root of CMS lines showed great advantages at former stage（0-20 d） after anthesis, whereas uptake and accumulation ability were not strong at late growth stage, but CMS lines had higher nitrogen translocation rate, nitrogen contribution rate and nitrogen utilization rate than those of their homotype lines, especially at nitrogen deficiency. These suggested that CMS lines had strong photosynthetic carbon production and nitrogen metabolization, improved nitrogen translocation and uitilization efficiency, thus, increased the grain filling ability and yields.