中文摘要：

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3种供氮形态（NH4^＋/NO3^-比为100/0,50/50和0/100）和2种水分条件（非水分胁迫及水分胁迫）下,研究了水稻苗期-分蘖期的生长及其水分利用效率.结果表明,苗期-分蘖期水稻在非水分胁迫条件下,NH4^＋/NO3^-比为50/50处理（NH4^＋、NO3^-混合处理）的生物量最大,比单一供NH4^＋-N和单一供NO3^--N的处理分别高49.63%和63.25%.而在水分胁迫条件下,单一供NH4^＋-N的处理生物量最大,比NH4^＋、NO3^-混合处理和单一供NO3^--N的处理分别高5.76%和484.0%;单一供NH4^＋-N其水分利用效率也最高,比NH4^＋、NO3^-混合处理和单一供NO3^--N的处理分别高11.36%和81.63%,而比非水分胁迫条件下的相应处理高12.39%.此外,单一供NH4^＋-N较单一供NO3^--N的处理水稻有较强的抗旱性,主要与其能保持相对较高的叶绿素含量、叶面积、分蘖数和净光合速率有关.

英文摘要：

By using nutrient solution culture and simulated water stress by PEG（6000）, 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 ） on water use efficiency （WUE） and the biological characteristics of rice plants at seedling-tillering stage were studied. The results showed that, under non-water stress, the biomass of rice plants were about 49.63 % and 63.25 % higher under the supply of mixture of NO3^- -N and NH4^＋ -N than either sole supply of NO3^- -N or NH4^＋ -N, respectively. However, under water stress, the biomass of rice plants were about 5.76% and 484.01% higher under sole ammonium supply than the other two treatments, WUE of rice plants were also 11.36% and 81.63% higher than the two treatments, while 12.39% higher than the same nitrogen form supply under non-water stress. Furthermore, rice plants grown with ammonium nutrition showed a stronger tolerance to water stress, due to their higher chlorophyll content, leaves area, tillers, and net photosynthetic rate et al. compared with those grown with nitrate nutrition.