Nitrogen Accumulation and Distribution in Rapeseed (Brassica napus L.) with Different Nitrogen Utilization Efficiencies for Grain Production

In this study, 98 conventional rapeseed (Brassica napus L.) varieties were grown with N0 treatment (0 kg N ha-1) and N1 treatment (60 kg N ha-1) in 2007-2008. Dry matter weight and content of nitrogen were tested at maturing stage. The rapeseed varieties were classified into six types based on their nitrogen use efficiency for grain production (NUEg) by the MinSSw method. The results showed that differences of NUEg in the varieties used in this study were significant. As NUEg increased, yield increased. The correlation analysis showed that NUEg was not significantly correlated with total amount nitrogen accumulation (rN0= -0.0245, rN1= -0.1131). NUEg had extremely significantly positive correlation with nitrogen distribution ratios in stems (rN0= -0.5941**, rN1= -0.4141**) and shells (rN0= -0.6007**, rN1= -0.5374**), but extremely significantly negative correlation with the amount of nitrogen in seeds (rN0=0.7954**, rN1=0.7239**). NUEg had extremely significantly positive correlation with total number of seeds also (rN0=0.5945**, rN1=0.5412**). NUEg and total amount of nitrogen accumulation influenced yield significantly. Cultivar breeding should be based on a certain total amount of nitrogen accumulation, and promote nitrogen to transport from vegetative organs to seeds, so as to achieve high yield and high nitrogen efficiency in rapeseed production.