关键词: 平邑甜茶, 小金海棠, 缺锌胁迫, 抗氧化能力, 植物激素

Abstract: The antioxidative capability and plant hormone level of two apple rootstocks under zinc-deficiency stress were investigated for exploring the difference of endurance and sensitivity to zinc-deficiency stress between two apple rootstocks. The seedlings of two apple rootstocks cultivars（Malus hupehensis Rehd. and M. xiaojinensis Cheng et Jiang）grown hydroponically under zinc- deficiency stress were tested. The changes in the antioxidant enzyme activity of superoxide dismutase（SOD），peroxidase（POD）and catalase（CAT），membrane lipid peroxidation level and the endogenous hormones content of indole-3-acetic acid（IAA），gibberellin（GA3），zeatin riboside（ZR）and abscisic acid（ABA）in plant leaves and roots were studied. The results showed decreased SOD activity，increase activities of POD and CAT and the content of MDA in response to zinc-deficiency stress. Comparing with the M. hupehensis Rehd.，the decrease of SOD activity of the M. xiaojinensis Cheng et Jiang was smaller，the increase of activities of POD and CAT were bigger，and the accumulation content of MDA in the seedling was less. After 45 days grown in a zinc-deficiency solution，the content of IAA and GA3 of the two apple rootstocks cultivars were both increased dramatically，and more increase were found in M. xiaojinensis Cheng et Jiang. On the contrary，the content of ZR and ABA of two cultivars roots were decreased under zinc-deficiency condition. The sensitivity and endurance of the two apple rootstocks seedlings to zinc-deficiency stress were different. The M. hupehensis Rehd. was more sensitive and its membrane lipid peroxidation level was higher under zinc-deficiency stress，while M. xiaojinensis Cheng et Jiang presented more potent antioxidant effect，had more plant hormones that promotes plant growth and had better endurance and resistance to the zinc-deficiency stress.