Abstract: By using the method of nutrient solution culture and simulated water stress with PEG6000, the effects of different nitrogen forms (NO₃^--N, NH₄⁺-N and the mixture of NO₃^--N and NH₄⁺-N) and water statuses (non-water stress and water stress conditions) on P distribution in the different parts of rice plants at the seedling-tillering stage were studied. Under water stress, P content in the different parts of NH₄⁺-N supplied rice plants was higher than that of the other two nitrogen forms supplied ones, meanwhile, P content in NO₃^--N supplied rice plants under non-water stress was higher than that under water stress, whereas water stress had no significant effect on P content in the rice plants supplied with NH₄⁺-N and the mixture of NO₃^--N and NH₄⁺-N. Regardless of water conditions, from the early tillering stage to the middle tillering stage, the ratio of P distributed to leaves and roots supplied with NH₄⁺-N singly and the mixture of NO₃^--N and NH₄⁺-N was reduced, while NO₃^-N nutrition only reduced the rate of P distributed to leaves at this stage. Furthermore, the increased rate of P accumulated in rice plants was higher under NH₄⁺-N supplied plus water stress than other treatments in this period.

Key words: nitrogen form, water stress, phosphorus, distribution, rice

摘要： 为探讨不同形态氮素营养对干旱条件下水稻P吸收与分配的影响， 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，在分蘖期设置3种供氮形态（NH4+N、NO3-N以及NO3-N和NH4+N相同浓度下等体积混合）和两种水分条件（非水分胁迫及水分胁迫）的耦合处理进行研究。结果表明： 1）在水分胁迫条件下，水稻植株及各部位含P量均是全NH4+N营养明显高于全NO3-N营养；同时，在分蘖期，全NO3-N营养水稻植株含P量明显低于非水分胁迫条件下的相应处理，但水分胁迫对全NH4+N以及NO3-N和NH4+N混合营养水稻含P量影响不大；2）在两种水分条件下，全NH4+N以及NO3-N和NH4+N混合营养均相对降低了水稻对吸收进入体内的P向叶片和根系的运输比例；而全NO3-N营养则只相对降低了水稻体内的P向叶片的运输比例。此外，由分蘖初期到中期，在水分胁迫条件下，全NH4+N营养水稻积累的P素增加比例最高。

关键词: 氮素形态, 水分胁迫, 磷, 分配, 水稻