UV-B辐射对光核桃光合作用和内源激素水平的影响

为了研究UV-B辐射对光核桃的生长发育及生理生化的影响，以光核桃(Prunus mira Koehne)实生苗为材料，模拟西藏地区的UV-B辐射环境，对其进行不同时间、不同强度的UV-B辐射(280~320 nm)处理，观测其生物学和生理学各项指标的变化。结果表明，UV-B辐射能抑制光核桃实生苗新叶生长、加速老叶脱落并促使叶片叶绿素含量降低；处理9天后，光核桃实生苗的净光合速率及气孔导度都有所降低。UV-B辐射处理期间，光核桃实生苗叶片ZR、GA含量升高，并随处理时间延长呈持续上升趋势；IAA含量从第3天开始呈持续下降趋势；叶片ABA含量从第3天开始上升，第9天达到最高值后小幅下降。

Influence of Ultraviolet Radiation on Photosynthesis and Hormone Levels in Prunus mira Koehne

In order to investigate effect of ultraviolet radiation on the growth,development,physiology and biochemistry of Prunus mira Koehne,which was used as the material in this experiment and cultured in the specially Tibet ultraviolet environment,treated with ultraviolet （280-320 nm） by different intensity at different time.During the period of experiment,the author checked these parameters：such as leaf number,chlorophyll,net photosynthetic rate,stomata conductance and the change of plant hormones.The results showed that,ultraviolet treatment could restrain the growth trend of Prunus mira,such as inhibited the new leaves growing,enhance the falling rate of old leaves and also reduce the content of chlorophyll.In the later period of treatment,net photosynthetic rate and stomata conductance was reduced,during the ultraviolet treatment,the contents of ZR,GA in Prunus mira leaves was increased,accompany with the treatment period,the trend was continued,from the third day,contents of IAA decreased continually for the whole treatment period,the contents of ABA had a great growth from the third day to ninth day and reached culmination,after that decrease for a little