典型玉米自交系氮素吸收利用特点的研究

在大田条件下，对8个代表性的玉米自交系在不同施氮水平下的氮素吸收与利用特点及与氮效率相关的一些性状进行了研究。结果表明：玉米自交系在产量、生物量和氮累积量上存在显著的差异。通过玉米自交系各性状与氮效率的关系的分析表明，低氮胁迫下，应选择抽丝期穗位叶叶绿素含量高、穗位叶叶面积大、籽粒含氮量高和氮收获指数大的自交系，高氮处理条件下，应选择抽丝期生物量大和成熟期生物量大的自交系。通径分析表明，氮吸收和氮利用效率对氮效率的作用均是直接作用大于间接作用。3个施氮水平条件下，对氮效率的直接作用是氮吸收效率大于氮利用效率。在低氮条件下，氮吸收效率的直接作用更强，而氮利用效率对氮效率的直接作用是随着施氮量的增加逐渐增强。在氮2、氮3处理中，吸收效率和利用效率的共同影响导致了产量差异，并且是吸收效率的影响较大；高氮处理则主要是吸收效率的影响。

Research on the Nitrogen Absorption and Utilization of Typical Maize Inbreds

The nitrogen (N) absorption, N utilization and some characters relationship with N use efficiency was studied on eight maize inbreds. The results were as follows: significant difference existed among inbred lines in yield, biomass and N accumulation amount. Correlation between NUE and characters of inbred lines were analyzed. The resulted showed that in choosing inbred lines, the following traits should be included, higher chlorophyll content and big area of ear leaf at heading period, higher N content of grain and harvest index at low N, and the big biomass at heading period and maturity at high N. Path analysis showed that the direct effect of N uptake and N utilization contributed to NUE was bigger than indirect effect of that. The direct effect of N uptake efficiency was bigger than the direct effect of N utilization efficiency at three applications N and uptake was more effectively at low N. The direct of utilization to NUE was gradually strengthened along with increasing N fertilizer. Both N uptake and utilization efficiency affected the inbred variations for grain yields at N2 and N3 treatment, and N uptake was the main influencing factor. While only N uptake was the mail-influencing factor at high N (N4) treatment.