干旱胁迫对酸枣幼苗生理特性的影响

以1年生酸枣幼苗为试验材料，选用盆栽控水试验法，研究土壤含水量80%(适宜水分，CK)、60%（轻度胁迫，L）、40%(中度干旱，M)和20%(重度干旱，S)4种不同强度干旱胁迫对酸枣幼苗相对含水率、过氧化产物含量、抗氧化酶活性和叶绿素荧光参数等生理特性的影响。结果表明：随着干旱胁迫程度的增加，酸枣幼苗的叶片相对含水率呈现总体下降的趋势；干旱胁迫引发膜脂过氧化，酸枣幼苗体内丙二醛（malondiadehyde，MDA）含量增加；干旱胁迫导致叶片渗透调节物质游离脯游氨酸（proline，Pro）的含量增加；随着干旱胁迫程度升高，超氧化物歧化酶（superoxide dismutase，SOD）、过氧化物酶（peroxidase，POD）和过氧化氢酶（catalase，CAT）的活性逐渐增强；干旱胁迫对酸枣幼苗的光合荧光特性影响显著，初始荧光（Fo）和非光化学猝灭系数（qN）显著增加，而最大荧光（Fm）、光化学猝灭系数（qP）、PSⅡ最大光化学效率 (Fv/Fm)和实际光化学效率(ΦPSⅡ)显著降低。综上，干旱胁迫对酸枣幼苗叶片的各生理指标均有一定影响，酸枣幼苗通过调节自身抗氧化酶活性和渗透调节物质等生理指标来适应逆境条件。

Effects of Drought Stress on Physiological Characteristics of Ziziphus jujuba var. spinosa Seedlings

One year seedlings of Ziziphus jujuba var. spinosa were used as test material, the pot water control method was used, and 4 treatments including 80% (suitable water, CK), 60% (light stress, L), 40% (moderate drought, M), and 20% (severe drought, S) soil moisture content were set up to simulate different levels of drought stress. The relative water content, peroxidation product content, antioxidant enzymes activities and chlorophyll fluorescence parameters and other physiological characteristics of Z. jujuba var. spinosa seedlings under different drought stresses were investigated. The results showed that with the increase of drought stress level, the relative water content of leaves of Z. jujuba var. spinosa seedlings generally showed a decreasing trend; the malondialdehyde (MDA) content of Z. jujuba var. spinosa seedlings showed an increased trend; the free proline (Pro) content increased, as well as the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT). The photosynthetic fluorescence characteristics of Z. jujuba var. spinosa seedlings were influenced by drought stress significantly. Under the drought stress, the initial fluorescence (Fo) and non-photochemical quenching coefficient (qN) increased significantly, while the maximum fluorescence (Fm), photochemical quenching coefficient (qP), maximum photochemical efficiency PSII (Fv/Fm) and actual photochemical efficiency (ΦPSII) were significantly reduced. Drought stress had significant effects on the physiological indexes of Z. jujuba var. spinosa seedlings. The physiological indexes including activities of antioxidant enzymes and osmotic adjustment substances content of Z. jujuba var. spinosa seedlings were regulated in response to the drought stress.