大叶相思叶片对白粉菌感病性的生化测定结果表明,抗坏血酸氢化酶活性和过氧化物酶同功酶活性随三个树龄级而增加,老龄抗病叶比幼龄感病叶活性高。补充抗坏血酸可使感染白粉菌的叶片转绿,延缓侵染斑的扩展。处理24小时后,感病嫩叶的抗坏血酸氧化酶活性显著提高,我们认为,叶片两种酶的活性与植株的抗性有关。 The results of biochemical determination of the susceptibility to the powdery mildew of Acacia macrostachya showed that ascorbate hydrogenase activity and peroxidase isoenzyme activity increased with age of three trees, and that of the aged resistant leaf was higher than that of the young susceptible leaf. Ascorbate supplementation can turn leaves infected with powdery mildew to green, delaying the spread of infected plaque. After 24 hours of treatment, the ascorbic acid oxidase activity of the susceptible young leaves increased significantly. In our opinion, the activities of the two enzymes in the leaves are related to plant resistance.