不同氮效率玉米干物质形成及氮素营养特性差异研究

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%～97.6%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。

Dry matter formation and nitrogen uptake in two maize cultivars differing in nitrogen use efficiency

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,...