Studies on the effects of different nitrogen forms on enzyme activity in flag leaves in wheat and protein and yield of grain for specialized end-uses

To understand reasonable utilization of nitrogen of end-use-specific cultivars,effects of different forms of nitrogen on activity of GS and GOGAT in flag leaves and grain yield and protein in wheat were studied under pot experiments.The results showed that NH4+-N increased activities of GS and GOGAT in flag leaves of strong-gluten cultivar,Yumai 34 and a medium-gluten cultivar,Yumai 49;while NO3——N increased activities of GS and GOGAT in flag leaves of a weak-gluten cultivar,Yumai 50.NH4+-N and NH2-N were beneficial but NO3——N was unfavorable to enhancement of grain protein content in all the three gluten types of cultivars.A positive correlation was found between grain protein content and GS activity in flag leaves.NO3——N increased grain yield of strong-gluten and weak-gluten cultivars while NH2-N increased grain yield of medium-gluten cultivars.