| 摘要: |
| [目的]探讨氮素形态对玉米幼苗体内水分状态、蒸腾速率、光合特性以及硝酸还原酶活性的影响.[方法]在沙培条件下分别供应铵态氮(NH4--N)、硝态氮(NO3--N)及1:1(质量比)的铵态氮和硝态氮(NH4--N +NO3--N)营养液,研究不同氮素形态对玉米幼苗根系、叶片硝酸还原酶活性、硝态氮含量、膜透性以及玉米叶片光合强度,气孔导度、蒸腾速率的影响,同时研究不同氮素形态对玉米幼苗水分状态供给和根系氧化还原活力的影响.[结果]单独供NO3--N时,玉米根系膜相对透性最小,叶片NR活性最高;供给NH4--N +NO3--N时,玉米植株NO3--N含量最高;单独供给NO3--N,玉米叶片气孔导度、光合强度、胞间CO2浓度及蒸腾速率最大,其次是NH4--N +NO3--N处理,而单独供给NH4--N时最小;单独供给NO3--N时,根系、叶片自由水与束缚水比值最高.单独供应NO3--N时玉米生物量最高.[结论]NO3--N对玉米幼苗最适宜. |
| 关键词: 氮素形态 玉米幼苗 气孔导度 蒸腾速率 自由水含量 光合强度 |
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| 基金项目:国家自然科学基金项目（30230230） |
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| Effect of N form on physiological mechanism and biomass in corn seedlings |
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| Abstract: |
| 【Objective】 The aim of this paper is to study the effect of N form on the water statues,transpiration rate,photosynthesis rate and nitrate reductase activities of corn seedlings.【Method】 Sand culture experiment was conducted in glasshouse at Northwest A & F University using maize (Zea mays L,var.Hudan) as an indicating crop.The N form was ammonium,1∶1 amonium/nitrate,nitrate supplied as the nutrient solution.【Result】 The results showed that the supply of amonia-N resulted in highest membrane penetrability in roots,the supply of the nitrate-N resulted in highest NR activity in leaf,and the stomata conductance and transpiration rate were all higher than either the ammonium-N treatment or the ammonium together with nitrate N mixed treatment.The ratio of free water to bound water was also higher for the nitrate N treatment.【Conclusion】 NO3--N is most suitable for corn seedlings. |
| Key words: N form maize (Zea mays L) seedling water status transpiration rate free water content stomata conductance |
