中文摘要：

以3 a生全球红葡萄（Vitis vinifera L. cv. Red Globe）为试材,用不同质量浓度的GA3在花前花后两次处理葡萄果穗后,研究其对葡萄果实成熟期叶片光合色素含量、光合及荧光特性的影响。结果表明,①GA3处理增加了葡萄叶片光合色素（PPC）的含量,20 mg.L-1GA3处理效果最显著,Chla、Chlb和Car含量分别较对照增加了13.2%、23.3%和38.6%（P〈0.05）,但由于Chla增加幅度小于Chlb,所以Chla/b降低;②GA3处理后叶片净光合速率（Pn）、光合有效辐射（PAR）、气孔导度（Gs）、胞间CO2摩尔分数（Ci）、蒸腾速率（Tr）和水分利用效率（WUE）都有不同程度的增加,但在一天当中发生改变的时间不同;③经不同质量浓度GA3处理,叶片初始荧光（Fo）、最大荧光（Fm）、光化学猝灭系数（qP）和PSⅡ实际光化学效率（ФPSⅡ）升高,暗适应下最大光化学效率（Fv/Fm）增大,但不明显。

英文摘要：

Experiment was conducted with 3-year-old Red Globe grape trees,the effect of GA3 on the photosynthetic characteristics and chlorophyll fluorescence were studied after spraying the GA3 on the fruit before and after blossoming.The results revealed that：①The content of photosynthetic pigment content increased after treated by GA3,the difference between the control and 20 mg·L-1 GA3 treatment was the most significant.Compared with the control,the chlorophyll a,chlorophyll b,and carotenoids increased by 13.2%,23.3% and 38.6%,respectively（P0.05）.The increase of chlorophyll a was much less than that of chlorophyll b,so that the ratio of chlorophyll a/b reduced;②The net photosynthetic rate（Pn）,stomatal conductance（Gs）,transpiration rate（Tr）,photosynthetic active radiation（PAR）,intercellular CO2 concenrtation（Ci）,and water use efficiency（WUE） of leaves increased in some different degrees,and their changing time varied in a day;③Minimal initial fluorescence（Fo）,maximal fluorescence（Fm）,photochemical quenching（qP）,and the quantum yield of electron transport PSⅡ（ФPSⅡ） increased,photochemical efficiency of PSⅡ（Fv/Fm） increased after treated by different concentration of GA3,but not remarkable.