Effects of medium moisture on leaf lipid peroxidation and protective enzyme activities in grafted cucumber seedlings | 基质湿度对黄瓜嫁接苗叶片膜脂过氧化及保护酶活性的影响

chinois. 以嫁接黄瓜幼苗为试材,在人工控制条件下,研究了基质湿度对黄瓜/黑籽南瓜嫁接苗和黄瓜自接苗叶片细胞质膜透性、丙二醛（MDA）含量及超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性的影响.结果表明：黄瓜嫁接苗和自接苗的细胞膜相对透性和MDA含量随干旱胁迫时间延长和胁迫强度加大而增加;SOD、CAT、APX活性均随胁迫进程呈先升后降的趋势,而POD活性则持续下降;黄瓜嫁接苗的细胞膜相对透性和MDA含量始终小于自接苗,保护酶活性始终高于自接苗.2种种植方式间比较,黄瓜嫁接苗在间作中,除细胞膜透性和MDA含量外,其它酶活性均高于单作,而自接苗的变化趋势与嫁接苗相反,说明黄瓜嫁接苗的大根系对适度干旱胁迫具有较强的适应性,在土壤水分竞争中占有优势.[著者文摘]

anglais. The effects of medium moisture on leaf MDA content, membrane permeability, superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT） and ascorbate ted seedlings （Cucurbita ficifolia as root stock）were investigated. T pe he roxidase （APX） activities in grafresults showed that MDA content and membrane permeability of grafted cucumber seedlings increased as medium moisture reduced. The activity of SOD, POD, CAT and APX of grafted cucumber seedlings and self-grafted cucumber seedlings in- Creased temporally and then decreased during water stress, while POD activity decreased continuously.MDA content and membrane permeability were higher and the enzyme activities were lower in self-grafted seedlings than in grafted ones under the same moisture gradient. The MDA content and membrane permeability of grafted seedlings were lower in intercropping than in single-standing. The results indicated that the big root volume of grafted seedlings brought about stronger adaptability to moderate drought, the grafted seedlings with larger roots showed advantages over self-grafted ones in water competition.