中文摘要：

通过田间小区试验,开展了两个氮素供应水平（N0和N180）下,两个不同氮效率玉米品种[氮高效品种先玉335（V1）低效品种吉单535（V2）]干物质形成与氮素营养特性差异研究。结果表明,在氮素胁迫条件下,氮高效品种先玉335具有较高的耐低氮能力,表现为N0处理其干物质量及吸氮量均显著高于氮低效品种吉单535的N180处理。成熟期,先玉335的子粒干物质量和吸氮量均显著高于吉单535,且N180处理显著高于N0处理 品种和氮素处理间的交互作用达极显著水平,表现为N180处理先玉335子粒干物质量和吸氮素最高。另外,两品种子粒中85.6%9~7.6%的碳来源于粒重形成阶段叶片的光合作用,仅2.4%~14.1%源于抽雄前营养体的碳素转移。先玉335子粒氮素来源更多依赖于生育后期根系对氮素的吸收和转移,N0和N180处理中,根系氮素吸收转移量对子粒的贡献分别为45.4%和59.3% 而吉单535子粒的氮素来源则以生育前期地上部营养体的氮素转移为主,N0和N180处理中,转移量对子粒贡献分别为65.5%和67.9%。先玉335的氮肥回收利用率、氮肥农学效率及氮肥偏生产力均高于吉单535。

英文摘要：

Field experiment was conducted to investigate dry matter accumulation and N uptake under two N levels（N0 and N180） in two maize cultivars with contrasting N use efficiency.The results indicated that Xianyu 335 with high N efficiency had great tolerance to N stress.The dry matter weight and N absorption of Xianyu 335 in N0 treatment were both higher than those of Jindan 535 in N180 treatment.In maturity stage,the dry matter weight and N absorption of grain in Xianyu 335 was significant higher than Jidan 535,and those in N180 treatment was higher than N0 treatment.Moreover,the interaction between variety and N application reached extremely significant level.The dry matter weight and N absorption of grain was highest in Xianyu 335 with 180 kg/ha N application.In addition,a majority of grain carbon（85.6%-97.6%） relied on photosynthesis in the stage of grain formation,only a minority of grain carbon（2.4%-14.1%） relied on carbon translocation from vegetative organs. For Xianyu 335,nitrogen in grain mainly relied on N uptake by root at reproductive stage,which accounted for 45.4% and 59.3% of total N of grain in N0 and N180 treatment respectively;but for Jidan 535,N in grain mainly relied on N translocation from vegetative 335 the nitrogen recovery use efficiency（NRUE）,nitrogen agronomic efficiency（NAE） and nitrogen partial factor productivity organs,which accounted for 65.5% and 67.9% of total N grain in N0 and N180 treatment respectively.In Xianyu（NPFP） were all higher than Jidan 535.