供氮形态和水分胁迫对水稻生长及氮素积累和分配的影响

为探讨不同形态氮素营养对水分胁迫条件下水稻生长及氮素积累和分配的影响,采用室内营养液培养及聚乙二醇(PEG6000)模拟水分胁迫处理的方法,在苗期设置5种供氮形态(NH_4~+/NO_3~-比为0/100,25/75,50/50,75/25,100/0)和2种水分条件(非水分胁迫和水分胁迫)的组合处理进行研究.结果表明,在水分胁迫条件下,NH_4~+/NO_3~-比为25/75处理的株高和叶面积最大,达到100/0处理的1.5和1.3倍.2种水分条件下,NH_4~+/NO_3~-为25/75处理的根长均为最大,其在非水分胁迫和水分胁迫下分别为100/0处理的6.8倍和3.3倍;非水分胁迫条件下植株不同部位氮积累量均高于水分胁迫条件.2种水分条件下,根系氮积累量均以0/100处理最大,茎部氮积累量以100/0处理最大,0/100处理最小;在非水分胁迫条件下,叶片的氮积累以100/0处理最大,水分胁迫下则是以75/25处理最大.在水分胁迫条件下,单一供应NO_3~--N可以提高水稻根系中氮素的积累,同时供应NH_4~+和NO_3~-( 75/25配比)可以促进氮在水稻叶片和茎中的积累和分配.

Effects of Nitrogen Forms and Water Stress on Growth and Nitrogen Accumulation and Distribution of Rice Plants

By using the method of nutrient solution culture and simulated water stress with PEG6000,the effects of different nitrogen forms(NO_3~--N,NH_4~+-N and the mixture of NO_3~--N and NH_4~+-N)and water statuses(non-water stress and water stress condition)on growth and N accumulation and distribution of rice plant were studied.The results obtained were as follows:The plant height and leaf area of treatment 25/75( NH_4~+/NO_3~-)was the maximal among treatments,which was 1.5 and 1.3 times of treatment 100/0 respectively,under water stress condition.Root lengh of treatment 25/75 was all the maximal among treatments under either non-water stress or water stress condition,which was 6.8 times of treatment 100/0 under non-water stress,and 3.3 times under water stress.N accumulation in different part of plant under non-water stress were all higher than that under water stress.Under two water condition,N accumulation in root of treatment 0/100 were all the maximal,and treatment 100/0 had the maximal N accumulation in stem,the lowest was treatment 0/100.Under non-water stress,leaf N accumulation of treatment 100/0 was the maximal,under water stress,leaf N accumulation of treatment 75/25 was the maximal.Under water stress,supply of single NO_3~--N might increase N accumulation in root,supply of mixture of NO_3~--N and NH_4~+-N could promote N accumulation and distribution in stem and leaf of rice plant.