Lewis O A M, Leidi E O, Lips S H
Plant Adaptation Research Unit, The Jacob Blaustein Institute for Desert Research, Ben Gurion University of the Negev, Sede Boqer Campus, Israel 84993.
New Phytol. 1989 Feb;111(2):155-160. doi: 10.1111/j.1469-8137.1989.tb00676.x.
The effect of ammonium and nitrate nutrition on maize and wheat grown hydroponically and salinity stressed was assessed from measurements of growth rate and gas exchange. In both maize and wheat the ammonium-grown plains were much more sensitive to salinity toxicity than nitrate-grown plants particularly when exposed to 60-80 mM salinity. Shoot growth was retarded to a far greater extent than root growth in salinity-stressed plants of both wheat and maize with either nitrogen source. There was no significant decrease of photosynthetic rate in salinity-stressed plants of either species fed nitrate or ammonium, except in severely wilted plants of both species fed nitrate or ammonium at the highest (80 mM) salinity concentration. The same was true for stomatal conductance, transpiration rate and transpiration ratio (water use efficiency). In nitrate-fed wheat, raising the calcium concentration from 2 to 12 mM in the presence of 60 mM salinity produced an 11% increase in growth. This effect is ascribed to improved nitrate uptake due to calcium protection of the nitrate transporter and was not evident in ammonium-grown wheat. Possible reasons for the differential effects of ammonium and nitrate nutrition are discussed.
通过测量生长速率和气体交换，评估了铵态氮和硝态氮营养对水培种植且受盐分胁迫的玉米和小麦的影响。在玉米和小麦中，铵态氮培养的植株比硝态氮培养的植株对盐分毒害更为敏感，尤其是在暴露于60 - 80 mM盐分的情况下。无论是小麦还是玉米，在受盐分胁迫且以铵态氮或硝态氮为氮源的植株中，地上部生长的受抑制程度远大于根部生长。在以硝酸盐或铵盐为养分的两种植物的盐分胁迫植株中，除了在最高（80 mM）盐分浓度下以硝酸盐或铵盐为养分的两种植物的严重萎蔫植株外，光合速率均无显著下降。气孔导度、蒸腾速率和蒸腾比率（水分利用效率）也是如此。在以硝酸盐为养分的小麦中，在60 mM盐分存在的情况下将钙浓度从2 mM提高到12 mM，生长增加了11%。这种效应归因于钙对硝酸盐转运蛋白的保护从而改善了硝酸盐吸收，而在铵态氮培养的小麦中不明显。文中讨论了铵态氮和硝态氮营养产生不同效应的可能原因。
