中文摘要：

以两种氮效率不同的油菜品种X-13和X-29为材料,在严格控制氮营养水平的砂培条件下,研究了不同施氮水平下两个品种油菜硝态氮累积量、硝酸还原酶活性、氮素吸收量、籽粒产量、氮效率等指标的差异特征.结果表明,与氮低效品种X-29相比,氮高效品种X-13的硝态氮累积量多,硝态氮再利用量大,叶片硝酸还原酶活性高,其氮素累积量也多,籽粒产量和氮效率也高,品种间差异显著.供氮水平提高,两品种的硝态氮累积量和再利用量都增大,叶片硝酸还原酶活性增强,氮素随着累积量增加,籽粒产量升高,而氮效率则下降.

英文摘要：

In this paper,two oilseed rape varieties named X-13 and X-29 were used as plant materials for sand culture with the different nitrogen （N） application levels to study the different effects of N application levels on accumulation amount of nitrate,nitrate reductase （NR） activity,absorption amount of N,seed yield and N efficiency in the two oilseed rape varieties.The results showed that compared with X-29,the nitrate N accumulation is higher,reutilization ratio of nitrate,the activity of NR in leaf,N accumulation,amount and seed yield are increased in the X-13 treatment.And the difference between the two varieties is significant.But the increasing of nitrogen application level,nitrate accumulation amount,reutilization ratio of nitrate,and the activity of NR in leaf increased and the N efficiency decreased in both oilseed rape varieties.