不同氮效率玉米品种灌浆期氮素转运特性和产量对氮素形态的响应

研究不同氮效率玉米品种登海605(DH605)和鲁单981(LD981)的产量、氮素吸收和氮素利用效率对氮素形态的响应及其生理机制。结果表明,在2015年和2016年,与LD981相比,DH605的平均产量分别提高17.2%和20.3%,成熟期植株氮素积累量提高8.5%和10.3%,氮素利用效率提高6.7%和8.5%,而且不受年份(除植株氮素积累量)、氮素形态及其交互作用的影响。结果表明,正常施氮条件下,LD981为低产氮低效品种,DH605为高产氮高效品种,主要表现为花后具有较高的抗氧化能力,延缓叶片衰老,维持花后较高的氮代谢酶活性,保证花后较强的氮素吸收和同化能力,获得高产同时引起子粒氮浓度下降。

Characteristics of Nitrogen Translocation during the Grain-Filling Period and Grain Yield of Different Maize Cultivars with Varied Nitrogen Efficiencies in Response to Different Nitrogen Forms

This study aimed to investigate the grain yield, shoot N accumulation and N utilization efficiency of maize cultivars Denghai605(DH605) and Ludan981(LD981) with varied N efficiencies in response to different N forms and further to reveal the related physiological mechanisms.The results showed that in 2015 and 2016, compared with LD981, the average yield of DH605 was increased by 17.2% and 20.3%, the shoot N accumulation at maturity increased by 8.5% and 10.3%, N use efficiency increased by 6.7% and 8.5%, respectively. The years, N forms and their interactions had no significant effects on the above parameters with the exception of a significant effect of the year on the shoot N accumulation at maturity. The results suggested that at a normal N application rate, LD981 had both lower yield and N efficiency but DH605 had both higher yield and N efficiency, the latter showing higher antioxidative ability to delay senescence, to maintain higher activities of key enzymes related with N metabolism, to improve N uptake and assimilation, and finally to gain higher yield but to decrease grain N concentration.