Difference Of Nitrogen Absorption And Utilization Between Hybrid Varieties And Their Parents In Rapeseed

Through testing the biomass and the content of N of each organ in hybrid varieties and their parents of rapeseed under different nitrogen application at bolting, beginning of flower and maturing stages to study the difference of nitrogen absorption and utilization between hybrid varieties and their parents, the main results were as follows:1. The seed yield in hybrid varieties was significantly higher than that of their parents. The main reason was that pods per plant and seeds per pod in hybrid varieties were significantly higher than that of their parents when applying the N fertilizer at the lower and medium level, while the three yield components were a little higher than that of their parents at the higher nitrogen application level .2. Before flowering, the content of N of each organ in hybrid varieties was lower than that of their parents at different N fertilizer application, but the difference was not significant. The difference of the amount of nitrogen in whole plant between hybrid varieties and their parents was very little at different N fertilization treatments, but the amount of nitrogen in leaves and its proportion contributing to the whole plant were all higher than that of their parents and in stem and branches contrary.3. At maturing stage, the content of N of each organ in hybrid varieties was lower than that of their parents, but the difference was not significant in seeds at all N fertilizer application level, and in pod shells, stem and branches and whole plant at lower nitrogen fertilizer application, while the difference was significant in pod shells, stem and branches and whole plant when applying the N fertilizer at the medium and high level. The amount of nitrogen in whole plant and pod shells in hybrid varieties was all obviously higher than that of their parents in lower nitrogen application level, but close to their parents in medium and higher nitrogen application level. And the amount of nitrogen in stem and branches in hybrid varieties was close to their parents in lower nitrogen, but obviously lower than that of their parent in medium and high level. Moreover, the amount of nitrogen in seeds and its proportion contributing to the whole plant were all significantly higher than that of their parents.4. Both the NUEp (nitrogen use efficiency for plant biomass) and NUEg (nitrogen use efficiency for grain production) in hybrid varieties had no significantly difference with their parents at the lower nitrogen fertilizer application level, while significantly higher than that of their parents at higher nitrogen fertilizer application level. The NHI (nitrogen harvest index) of hybrid varieties was significantly higher than that of their parents.5. The hybrid varieties of rapeseed had obvious predominance to absorb and utilize nitrogen. They absorbed more nitrogen at lower soil fertility and had higher nitrogen use efficiency under higher N fertilizer application.