Study on nitrogen accumulation in Rapeseed (Brassica napus. L) with different nitrogen utilization efficiency for grain production

In this study, 98 conventional rapeseed (Brassica napus. L) cultivars were cultured in 2007-2008 under different nitrogen application levels. Through testing dry matter weight and content of nitrogen, the tested rapeseed cultivars were classified into 6 types based on their nitrogen use efficiency for grain production (NUEg) level by the MinSSw method, to study their characteristics of nitrogen accumulation. Results showed that differences of NUEg in the cultivars used in this study were significant. The yield increased with the increase of NUEg. Differences of total amount of nitrogen accumulation was slight in different types. As NUEg increased, the amount of nitrogen accumulation of stem and shell decreased, and the amount of nitrogen accumulation of seed increased. The correlation analysis showed that NUEg had extremely significantly positive correlation with amounts of nitrogen in stems and shells at ripening stage, but it had extremely significantly negative correlation with the amount of nitrogen in seeds. The study of path analysis indicated that it was most important for NUEg to decrease nitrogen accumulation of vegetative organs, and secondary was to increasing nitrogen accumulation of seeds.