GA_3对葡萄果实成熟期叶片光合及荧光特性的影响

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%(P0.05),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。

Effects of GA3 on the Characteristics of Photosynthesis and Chlorophyll Fluorescence of Grape Leaves during the Maturation Stage

Experiment was conducted with 3-year-old Red Globe grape trees,the effect of GA_3 on the photosynthetic characteristics and chlorophyll fluorescence were studied after spraying the GA_3 on the fruit before and after blossoming. The results revealed that:①The content of photosynthetic pigment content increased after treated by GA_3,the difference between the control and 20 mg·L~(-1) GA_3 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 (P<0.05).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(P_n),stomatal conductance(G_s),transpiration rate(T_r),photosynthetic active radiation(PAR),intercellular CO_2 concenrtation (C_i),and water use efficiency(WUE) of leaves increased in some different degrees,and their changing time varied in a day; ③Minimal initial fluorescence (F_o),maximal fluorescence (F_m),photochemical quenching (qP),and the quantum yield of electron transport PSⅡ (ФPSⅡ) increased,photochemical efficiency of PSⅡ(F_v/F_m) increased after treated by different concentration of GA_3,but not remarkable.