| 摘要: |
| 【目的】研究干旱胁迫对光核桃幼苗光合生理特性的影响，为其栽植地点选择和水分管理提供理论依据。【方法】以野生种子培育的3年生盆栽光核桃实生苗为供试材料，采用自然干燥法研究土壤含水量分别为26.2%～32.3%（T1阶段）,18.2%～20.6%（T2阶段），10.1%～12.7%（T3阶段）和5.1%～7.7%（T4阶段）时，光核桃幼苗光合特性及保护酶活性的变化。【结果】随着干旱胁迫的加剧，光核桃幼苗的净光合速率逐渐下降，在T3和T4阶段下降幅度较大，主要限制因子为气孔导度；在干旱胁迫的T3和T4阶段,水分利用效率（WUE）均值显著高于T1和T2阶段；在水分胁迫的T3阶段，光核桃幼苗的SOD、POD和CAT活性均显著低于T1阶段，且MDA含量显著升高。【结论】一定程度的干旱胁迫能提高光核桃幼苗的WUE；土壤含水量为10.1%～12.7%时，光核桃幼苗表现为受干旱胁迫显著，这可为光核桃栽植地点的选择和水分管理提供参考。 |
| 关键词: 光核桃 光合特性 保护酶 干旱胁迫 |
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| 基金项目:国家科技支撑计划项目(2006BAC01A04,2007BAC06B02）；西藏自治区2009基金课题“西藏雅鲁藏布江流域河谷半干旱区乡土植物抗旱性研究”资助 |
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| Photosynthetic characteristics and protective enzyme activities of Prunus mira seedlings to drought stress |
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| Abstract: |
| 【Objective】Study on the photosynthetic and physiological characterstics of Prunus mira was done to provide theoretical basis for locational selection and their water supply during growing.【Method】Using the three-year-old wild P.mira wild seedlings as experiment materials，the change of photosynthetic characteristics and the protective enzymes activities in P.mira to natural drying conditions（the treatments of soil moisture T1,T2,T3,T4 were 26.2%-32.3%,18.2%-20.6%，10.1%-12.7%，5.1%-7.7% in field capacity） were studied.【Result】The results were as follows：the net photosynthetic rate decreased with the aggravation of drought stress because the main factor of the stomatal conductance declined.The value of WUE under T3 and T4 was above that of under T1 and T2 significantly.Under treatment T3，the activities of SOD，POD，CAT were significantly lower than those during treatment T1，but MAD significantly increased；Keeping the soil moisture to 10.1%-12.7% in this experiment，P.mira was subject to increase.【Conclusion】The WUE of P.mira could be increased significantly after experiencing certain drought stress.This is the reference for the planting location and the irrigation arrangements during the period of P.mira growing |
| Key words: Prunus mira photosynthetic characteristic protective enzyme drought stress |
