Difference of nitrogen use efficiency and characters of nitrate accumulation and utilization between oilseed rape varieties under different N application levels

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.