关键词: 杧果, 增强UV-B辐射, 损伤, 抗氧化

Abstract: In order to research the effects of the enhanced UV-B radiation on the injuries and the antioxidation responses of adult mango trees，the adult‘Jinhuang’mango trees in the field were treated with the enhanced UV-B radiation from 24 to 120 kJ ? m-2 ? d-1 in gradient of 24 kJ ? m-2 ? d-1，and those in the natural sunlight were used as the control. The yield of single tree，the qualities of fruits and the tendencies of the physiological and biochemical indicators related to the injuries and the antioxidation of leaves were detected during the period of the experimental treatments. With the increases of the intensities of the enhanced UV-B radiation over 48 kJ ? m-2 ? d-1，the yield of single tree，the size of fruit and the flavor and nutrient qualities decreased more and more. With the increase of the intensities of the enhanced UV-B radiation，the content of chlorophyll and the level of Pn decreased more and more，and the content of MDA and the relative conductivity increased more and more. The activities of SOD of the control were lower than those of the treatments below 72 kJ ? m-2 ? d-1 and higher than those of the treatments over 96 kJ ? m-2 ? d-1. The activities of POD of the control were lower than those of the treatments below 72 kJ ? m-2 ? d-1 and higher than those of the treatment 120 kJ ? m-2 ? d-1 all the time and the treatment 96 kJ ? m-2 ? d-1 during the late period. The activities of CAT of the control were lower than those of all the treatments all the time. All the treatments decreased the content of vitamin C and increased the contents of the components such as reduced GSH，flavonoid and polyphenol. In sum，the enhanced UV-B radiation over 48 kJ ? m-2 ? d-1 injured the trees，reduced the yield and made the fruits qualities getting worse with dosage effects，and the damage in trees appeared accumulation effects. The treatments below 72 kJ ? m-2 ? d-1 intensified the activities of antioxidative enzymes，and increased the substances accumulations of antioxidant and absorption of UV-B radiation，and consumed more vitamin C，which reinforced free radicals scavenging abilities and dissipation of enhanced UV-B radiation as far as possible，then minimized UV-B radiation damage. The treatments over 96 kJ ? m-2 ? d-1 inhibited the activities of SOD and POD and reduced the substances accumulations of antioxidant and absorption of UV-B radiation during the experiment，which resulted in cumulating more free radicals and strengthening the stress of the enhanced UV-B radiation，then led to more serious injury to plants.

Key words: mango, enhanced UV-B radiation, injury, antioxidation