沙棘耐干旱胁迫的生理生化响应研究

摘要

Hippophae rhamnoides Linn.is commonly used as ecological and economic tree species for vegetation restoration and ecological reconstruction in arid and semi-arid areas in China.The paper studies the changes of physiological and biochemical indexes under drought stress condition and the response characteristics and laws to drought stress in leaves of Hippophae rhamnoides Linn,which can provide experiment basis for afforestation and ecological restoration of ecological species in the arid areas.The changes of physiological and biochemical indexes such as the chlorophyll (Chl)content and protective enzyme activity,and the correlation of physiological indexes are analyzed in seven soil moisture gradients, the response characteristics and laws to soil drought stress of the main physiological and biochemical indexes are illustrated in potted H.rhamnoides leaves by water controlled test.The results show that with the decrease of the relative water content (RWC)of soil, leaf relative water content (LRWC)and the chlorophyll (Chl)content decrease,the cell membrane permeability and the content of MDA increase gradually,and the activity of superoxide dismutase (SOD)and peroxidase (POD)increases first and then decreases,the soluble sugar (Ss)content and the proline (Pro)content increase.There were higher correlation coefficients between the LRWC and the cell membrane permeability,and between the Chl content and Pro.%沙棘是我国干旱半干旱地区植被修复和生态重建中常用的生态与经济树种，研究其在干旱胁迫条件下的叶片生理生化指标的变化，深入了解沙棘对对干旱胁迫的响应特征和规律，可为干旱区生态树种的造林绿化与生态修复研究提供试验依据。文章采用盆栽控水试验，研究了沙棘苗木叶片在7个土壤水分梯度下的叶绿素含量、保护酶活性等生理生化指标的变化，分析了各生理指标的相关性。结果表明：随着土壤相对含水量（RWC）的降低，叶片含水量（LRWC）及叶绿素（Chl）含量逐渐降低，细胞膜透性逐渐增大，MDA 含量逐渐增加；超氧化物歧化酶（SOD）与过氧化物酶（POD）两种抗氧化酶活性先升高后降低，可溶性糖（Ss）含量与脯氨酸（Pro）含量增加；叶片相对含水量与细胞膜相对透性之间、细胞膜相对透性与叶绿素含量、细胞膜相对透性与渗透调节物质之间均存在极显著的正相关关系。