Physiological characteristics of shoot of oilseed rape cultivars with different nitrogen use efficiency at different nitrogen utilization levels

To provide a scientific foundation for breeding and application oilseed rape cultivars with high nitrogen efficiency,the relationshie between physiological characteristics such as chlorophyll contents,the activity of nitrate reductase(NRA),NO3-contents and its total amounts and re-transferring organic nitrogen in function leaves of 3 oilseed rape(742,Xiangyou 15,Huiyou 50) at different growing periods were studied by means of greenhouse experiments both under nitrogen application conditions and nitrogen-deficiency condition.The result indicated that nitrogen application had apparent effects on shoot physiological characteristics during the growing periods,all of them increased with the increasing ratio of nitrogen.Under nitrogen application conditions,chlorophyll contents,NRA in function leaves,NO3-contents and amounts,and re-transferring organic nitrogen in growing periods were closely related with oilseed rape cultivars Nitrogen Use Efficiency(NUE).All of them might be the factors to indicate the high NUE of varieties.Under nitrogen-deficiency condition,NRA in function leaves,NO3-amounts and re-transferring organic nitrogen were closely related with oilseed rape cultivars NUE,All of them might be the factors to indicate the high NUE of oilseed rape cultivars,while chlorophyll contents and NO3-contents was not.