Study on the Differences of Dry Matter Production and Yield Components in Rapeseed with Different Nitrogen Utilization Efficiency for Grain Production

[Objective]The research aimed to study the differences of dry matter production and yield components in rapeseed(Brassica napus L.) with different nitrogen utilization efficiency for grain production(NUEg).[Method] With B.napus cultivars as materials,through testing dry matter weight,the nitrogen content of different organs and yield components in mature period were measred.The tested rapeseed cultivars were classified into 6 types based on NUEg by the MinSSw method,so as to study their characteristics of dry matter nitrogen accumulation and distribution.[Result]The results indicated that differences of NUEg in different types varied significantly.With increasing of NUEg,seed yield,the ratio of dry matter weight of seed yield to total dry matter weight and number of pods increased,but the ratio of dry matter weight of stem and branches to total dry matter weight reduced.NUEg was highly significantly positive correlation with seed yield(r2007=0.684 0** and r2008=0.737 4** separately) and the ratio of dry matter weight of seed yield(r2007=0.570 3** and r2008=0.535 4** separately).[Conclusion] To improve NUEg in production,the variety with high yield and high number of pods was needed,and reasonable cultivation measures was also needed to make photosynthate translocate from stem and branches to pods to improve the ratio of dry matter weight of seeds.