Analysis of Nitrogen Metabolism in Roots and Uptake Characteristic of Wheat Cultivars with Different Nitrogen Efficiency at Seedling Stage
In order to clarify the physiological mechanisms of higher nitrogen use efficiency of wheat,the difference of nitrogen metabolism in roots and uptake characteristics of wheat cultivars with different nitrogen efficiency were investigated.Under hydroponic conditions,the nitrogen metabolism in roots and uptake kinetics to NO3-and NH4+ of N high efficiency wheat variety Luomai 18 and N low efficiency wheat variety Xinong 509 were studied.The results showed that the GS activity,NR activity,free amino acids concentration and soluble protein concentration in root of Luomai 18 were higher than those of Xinong 509.But the nitrate concentration and ammonium concentration in root of Xinong 509 were higher than those of Luomai 18.The maximum absorption rate(Vmax) to NO3-and NH4+ of Luomai 18 were higher than those of Xinong 509.But the affinity(1/Km) of Xinong 509 was higher than that of Luomai 18.In conclusion,the root absorptive capacity to NO3-and NH4+ and assimilative capacity of Luomai 18 was significantly higher than that of Xinong 509.There is a mutually reinforcing relationship between wheat roots absorption and assimilation to NO3-and NH4+.