【摘要】 在ＰＥＧ诱导的水分胁迫下，ＳＯＤ活力在不同抗旱性的玉米品种或杂交组合中均呈现下降─回升─下降的变化趋势；ＣＡＴ活力在抗旱性强的品种中先升（或基本不变）后降，而在抗旱性弱的品种中一直降低；ＰＯＤ活力在所有品种均呈明显降低。同时，叶片质膜透性增大，叶绿体和线粒体超微结构受损，抗旱性强的品种受损程度较轻。ＳＯＤ和ＣＡＴ活力与质膜、叶绿体和线粒体膜系统结构的损伤程度呈负相关，与品种抗旱性呈正相关，可作为玉米抗旱鉴定的生化指标；而ＰＯＤ活力与上述膜系统的损伤程度及品种抗旱性相关不大。更多还原

【Abstract】 When exposed to water stress induced by PEG, the activity of SOD in the maize seedlings with different drought-resistance lowered at the beginning and then increased and then lowered again; the activity of CAT went up (or almost did not change) at the beginning and then lowered in the strong drought-resistance genotypes but lowered straight in the weak droughtresistance genotypes; the activity of POD lowered apparently in all genotypes. At the sametime, the permeability of plasma membrane increased; the super-microstructures of chloroplasts and mitochondria in the leaves were damaged, and the damaged degree was lighter in the strong drought-resistance genotypes than that in the weak drought-resistance genotypes. The activities of SOD and CAT were negatively related to the damaged degree of plasmalemrna and chloroplasts and mitochondria membrane systems, but positively related to the drought-resistant properties of the genotypes, thus may be used as the biochernical appraisal indexes of drought-resistance of matte. However, the correlation between POD activity and the damaged degree of the membrane systems and the correlation between POD activity and the drought-resistant properties of the genotypes were not apparent.更多还原