UV-B辐射增强影响芒果成年树栽培表现和光合作用的生理生化机制研究

大气臭氧层变薄导致到达地面的UV-B辐射增强，热带地区紫外辐射强烈，UV-B辐射增强会影响芒果的栽培表现和光合作用。通过人工模拟不同强度梯度的UV-B辐射增强处理芒果成年树，观测树体栽培表现、叶片和果实活性氧代谢变化，探讨芒果苷积累与UV-B辐射增强强度变化的关系及其在活性氧代谢中的作用，从而确定促进和抑制芒果生长发育的UV-B辐射增强强度范围。再通过合理的低和高强度的UV-B辐射增强处理芒果成年树，调查栽培表现差异，观察叶片显微和超微结构改变，检测叶片光合作用一系列重要生理生化指标和芒果苷含量的变化，探讨芒果苷在芒果光合作用对UV-B辐射增强响应中的作用，确定UV-B辐射增强影响芒果光合作用的特征，总结出低和高强度UV-B辐射增强分别促进和抑制芒果果实生长发育和叶片光合作用的生理生化机制。本研究可发展果树光合作用和抗光照逆境生理理论，指导制定芒果适应UV-B辐射增强环境的合理栽培技术。

Reductions of ozone layer have led to a substantial increase in UV-B radiation on the surface of earth. The intensive UV radiation in the tropical region can influence the photosynthesis of the tropical fruit trees and their field performances. In this study, Some mango adult trees will firstly be treated with various doses of enhanced UV-B radiation, and then the growth and yield changes of the trees,as well as the metabolites of reactive oxygen species in leaves and fruits will be detected, at the same time, the mangiferin accumulation in leaves and fruits after UV-B radiation as well as its effects on the metabolism of reactive oxygen species will be analyzed too. From the experiments,the ranges of the UV-B radiation of improving and inhibitting the growth and development of mango trees will be determined.The other mango adult trees then will be treated accordingly, and the differences in the field performances, the microstructures and the ultrastructures of leaves, the content of magiferin in leaves, and the physiological and biochemical parameters related to photosynthesis will be compared in different treatments, from these data, the effects of mangiferin on the responses of mango trees photosynthesis to the enhanced UV-B radiation will be understood, and the physiological and biochemical responses of mango trees photosynthesis to the UV-B radiation will be determined.The physiological and biochemical mechanisms of UV-B radiation on the growth and development of mango fruits will be formulated. The results of this study will improve the theories of fruit tree's photosynthesis and the resistence in light stress, and provide the theoretical basis to improve the adaptability of mango trees to the enhanced UV-B radiation.