水分胁迫对长柄扁桃叶片含水量及保护酶活性的影响

利用PEG-6000根际模拟土壤水分胁迫的方法,对长柄扁桃(Amygdalus pedunculata)幼苗进行了不同程度的水分胁迫处理,研究在不同水分胁迫下长柄扁桃叶片相对含水量及膜脂过氧化作用的变化。结果表明,随着胁迫时间的延长和胁迫强度的加大,叶片相对含水量持续下降,MDA和质膜透性逐渐增大,但在胁迫的前期,下降和上升幅度相对较小。POD活性在不同程度水分胁迫下表现出先降后升的趋势,CAT活性表现出先升后降的趋势,在轻、中度胁迫下SOD活性先升而后降低,在重度胁迫下呈现出降、升、降的变化。三种酶活性在胁迫结束时除重度胁迫处理略低于对照外,其余各处理均高于对照,表明长柄扁桃对干旱有较强的适应能力。

Effects of water stress on the system of defense enzymes and RWC of Amygdalus pedunculata leaves

Amygdalus pedunculata seedlings were treated with PEG- 6000 solutions of different concentrations to imitate drought stress. The changes of relative water content and the membrane lipid peroxidation of leaves were studied. The results showed that the RWC decreased, whereas both the MDA content and the permeability of plasma membrane increased with the increase of PEG concentration. But in the early period of the treatment the changes were not obvious. POD activity showed decreasing first and then increasing. CAT activity increased at first and then decreased. SOD activity showed the same as POD under the light and middle concentration of the PEG drought stress. But it decreased at last under the stronger drought stress. The activities of the SOD .POD and CAT were all higher than that of the CK treatments except the stronger drought stress. All this suggested that the Amygdalus pedunculata has strong ability to fight a drought.