中文摘要：

在高氮和低氮条件下，对高产氮高效型、高产氮低效型、低产氮高效型、低产氮低效型四个类型玉米自交系氮效率筛选指标进行分析。结果表明，施用氮肥后，高产氮高效型和高产氮低效型根系氮素转移量增加，对子粒氮的贡献率提高。低氮下高产氮高效型根系氮转移量对子粒氮的贡献率高于高产氮低效型，高氮和低氮条件下两种基因型子粒氮主要来源于粒重形成阶段营养体的转移，而氮素不足时高产氮高效型后期根系氮素吸收能力比高产氮低效型更具有优势。无论高氮还是低氮条件下，对高产氮高效基因型的筛选，子粒吸氮量和吐丝期茎叶总氮量是重要的辅助筛选指标。

英文摘要：

The nutrient indices of four different N-efficiency maize inbred lines： high yield with high N efficiency, high yield with low N efficiency, low yield with high N efficiency and low yield with low N efficiency, were studied under high and low nitrogen fertilizer application rates. The results show that the N contents in stems and leaves and their transfer amount to grains are important indices for the screening of high yield with high N-efficiency genotype of maize, regardless of the N fertilizer application rates. The application of N fertilizer can increase the absorption and transfer of N from vegetative parts to grains. The contribution rate to grain N accumulation transferred from the vegetative parts are higher than from the roots at anthesis stage in all genotypes of maize under both high and low N application rates, but the N absorption amount and transfer rate from roots to grains are higher with high yield with high N-efficiency genotype when N is applied at low level. The contribution rate to grain N accumulation through the transfer from vegetative parts in high yield with high N efficiency type is higher than that in high yield with low N-efficiency type at both N application conditions. Therefore, both the N absorb amount and the total N content in the stem and leaf are important indices for the screening of high yield with high N-efficiency genotype of maize.