不同氮效率玉米自交系对氮素供应的反应

以对氮反应有典型差异的玉米自交系自330和陈94—11为材料，研究了不同供氮水平对其生物量和氮素吸收、利用的基因型差异。结果表明，植株的株高、叶片数、氮浓度、含氮量以及地上部生物量随着供氮水平的降低而降低，但根系的生物量、根冠比和氮素的根冠比却呈上升趋势。自330在氮素胁迫的条件下，具有较高的耐低氮能力。两个基因型玉米自交系吸氮量表现出的差异不是由于其氮含量造成的，而是由于根系生物量的差异造成的。

Responses of Maize Inbred Lines with Contrasting N Efficiency to Different Nitrogen Supplies

Two maize inbred lines (Zi330 and Chen94-11) which were significantly different in N efficiency were grown in solutions supplied with different nitrogen to study the differences in N uptake and utilization by maize plants. The results showed that dry weight of shoot, N content decreased for both Zi330 and Chen94-11 as the N supplying decreased, but dry weight of root and root/shoot ratio increased. Zi330 with a higher N efficiency than Chen94-11 had a great tolerance to low N stress. The dry weights of both shoot and root for Zi330 were higher than for Chen94-11 when they were in low N condition. The variation of N use efficiency for the two maize inbred lines was due to the difference in root biomass, rather than N concentration in root.