A hydroponic experiment was conducted to study the effect of partial replacement of NO-3-N by NH4+-N on the seedling growth and organic acid content of tomato (Lycopersicon esculentum Mill.). A completely randomized d...A hydroponic experiment was conducted to study the effect of partial replacement of NO-3-N by NH4+-N on the seedling growth and organic acid content of tomato (Lycopersicon esculentum Mill.). A completely randomized design was established with three replications and five treatments, i.e., NO-3-N/NH4+-N of 100/0, 75/25, 50/50, 25/75 and 0/100. Results showed that 25% replacement of NO3--N by NH4+-N significantly (P = 0.05) improved fresh and dry weight, revealing that a proper percentage of NH4+-N was important for tomato nitrogen nutrition. This could increase the plant growth even though tomato was a crop that preferred nitrate nutrition. Also an increase in the proportion of NH4+-N in the nutrient solution led to a significant decrease (P = 0.05) in malate, citrate and fumarate. However, the 25% NH4+-N plus 75% NO3--N treatment had no significant effect (P = 0.05) on the 2-ketoglutarate, succinate or oxalic acid content, showing that only some organic acids in tomato plants were affected. Only pyruvate increased significantly (P = 0.05), and it only increased for 25% and 50% replacement of NO3--N by NH4+-N. Metabolism of these organic acids, especially malate, citrate and fumarate, should be further studied at the molecular level in vegetables applied with different nitrogen forms.展开更多
温室气体 ,特别是 CO2 的排放和减排问题已经引起了国际社会的极大关注。分析并借鉴化肥生产工艺 ,用氨水喷淋火电站锅炉排烟烟气来吸收 CO2 ,不仅可以达到 CO2 减排的目的 ,还可以获得优质化肥。由于在高于 60℃的环境温度下碳酸氢铵...温室气体 ,特别是 CO2 的排放和减排问题已经引起了国际社会的极大关注。分析并借鉴化肥生产工艺 ,用氨水喷淋火电站锅炉排烟烟气来吸收 CO2 ,不仅可以达到 CO2 减排的目的 ,还可以获得优质化肥。由于在高于 60℃的环境温度下碳酸氢铵会分解为 NH+4和 HCO- 3 ,研究 HCO- 3 中重新返回大气的二氧化碳量是非常必要的 ,进而可以评估这种减排方法的应用价值。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 30270790) and National Post-doctoral Foundation of China (No. 2003033494).
文摘A hydroponic experiment was conducted to study the effect of partial replacement of NO-3-N by NH4+-N on the seedling growth and organic acid content of tomato (Lycopersicon esculentum Mill.). A completely randomized design was established with three replications and five treatments, i.e., NO-3-N/NH4+-N of 100/0, 75/25, 50/50, 25/75 and 0/100. Results showed that 25% replacement of NO3--N by NH4+-N significantly (P = 0.05) improved fresh and dry weight, revealing that a proper percentage of NH4+-N was important for tomato nitrogen nutrition. This could increase the plant growth even though tomato was a crop that preferred nitrate nutrition. Also an increase in the proportion of NH4+-N in the nutrient solution led to a significant decrease (P = 0.05) in malate, citrate and fumarate. However, the 25% NH4+-N plus 75% NO3--N treatment had no significant effect (P = 0.05) on the 2-ketoglutarate, succinate or oxalic acid content, showing that only some organic acids in tomato plants were affected. Only pyruvate increased significantly (P = 0.05), and it only increased for 25% and 50% replacement of NO3--N by NH4+-N. Metabolism of these organic acids, especially malate, citrate and fumarate, should be further studied at the molecular level in vegetables applied with different nitrogen forms.
