Effects of different nitrogen form and water status on biological characteristics of rice plants at seedling-tillering stage: Effects on the partitioning of N and assimilates to different parts

摘要

By using the method of nutrient solution culture and simulated drought stress by PEG(6000, polyethyleneglycol), the effects of different nitrogen (N) form (NO_3~- -N, NH_4~+-N and the mixture of NO_3~- -N and NH_4~+-N) and water status (non water stress and 5% PEG osmotic stress) on assimilates and N distribution in rice plants at tillering stage were studied. NO_3~- and the mixture of NO_3~- and NH_4~+ increased dry matter accumulation in roots in drought treatments, while NH_4~+ nutrition resultedin the tendency of more assimilates partitioning to shoots. Less N was absorbed by NH_4~+-N supplied plants under non-water stress, neither did NOs_3~- -N supplied plants under osmotic stress. On the contrary, more N was absorbed by NH_4~+-N supplied rice plants under osmotic stress.