CO2浓度对冬小麦氮代谢的影响

 采用全硝态氮霍格兰营养液为培养基质，在自然光与遮光条件下分别对冬小麦植株进行增加CO2浓度处理，分期测定其体内NO3--N、NH4+-N、全氮量、吸氮量及硝酸还原酶活性（NRA），研究CO2对小麦氮代谢的影响。结果表明，无论遮光与否，增加CO2浓度均增强了植株对NO3--N的吸收、同化能力。但对地上部与根部的影响不同，施加CO2，地上部硝态氮、铵态氮浓度及NRA均有所降低，而植株由溶液中吸收的硝态氮及吸氮总量增加；与地上部相比，CO2对根部硝态氮、铵态氮浓度影响较小，趋势相似；培养期间，施CO2极显著的提高根部NRA，增强根部对硝态氮的同化能力。

Effect of CO2 Concentration on Nitrogen Metabolism of Winter Wheat

Hoagland's solution of water culture medium was used to study the effect of CO2 elevated on nitrate metabolism of wheat under normally natural light and light-shaded conditions. NO3--N, NH4+-N, nitrate reductase activity, total uptake N by wheat plants during solution cultural period and total N in plants were determined for comprehensive evaluation of the effect. Results showed that under both natural light and light-shaded conditions, addition of CO2 increased NO3--N uptake and its assimilative capabilities by plants. However, there were some difference between shoots and roots. With increase of CO2 concentration, the concentration of NO3--N and NH4+-N as well as nitrate reductase activity all decreased in shoots while the difference was not so distinct in roots, and the nitrate reductase activity did not decrease, but increase. Since NO3--N uptake by plants from the solution and the total N in plants were much enhanced by CO2 addition, it may be concluded that addition of CO2 has resulted in rise of nitrate absorption, assimilation and metabolism of wheat.