三叶青1年生实生苗和6年生扦插苗光合效应比较

Comparison of Photosynthetic Effects of One-year Seedlings and Six-year Cuttings of Tetrastigma hemsleyanum Diels et Gilg

为了解怀玉山三叶青1年生实生苗和6年生扦插苗二者之间光合效率的差异,采用Li-6400光合仪和SPAD-502Plus便携式叶绿素测定仪对怀玉山三叶青1年生实生苗和6年生扦插苗二者之间的叶绿素含量、光合特性和叶绿素荧光参数进行测定。结果表明,怀玉山三叶青1年生实生苗和6年生扦插苗的叶绿素含量间无显著差异;1年生实生苗和6年生扦插苗净光合速率(Pn)、气孔导度(Gs)、胞间CO_(2)浓度(Ci)和气孔限制值(Ls)间差异显著,而二者的蒸腾速率(Tr)、水分利用效率(WUE)和瞬时羧化速率(CUE)间无显著差异;在光照条件下,1年生实生苗与6年生扦插苗的PSⅡ最大量子产量(F_(v)/F_(m))差异极显著,而饱和脉冲激发最大荧光值(F_(m)’)、最小荧光值(Fo’)以及捕获激发能效率(F_(v)’/F_(m)’)无显著差异;在遮光条件下,1年生实生苗与6年生扦插苗的F_(v)/F_(m)和PSⅡ潜在活性(F_(v)/Fo)差异显著,而初始荧光(Fo)和暗时最大荧光(F_(m))间无显著差异。怀玉山三叶青6年生扦插苗光合效率强于1年生实生苗,且光合效率与Gs、Ci、Ls、F_(v)/F_(m)、F_(v)/Fo相关。

To understand the difference in photosynthetic efficiency between one-year seedlings and six-year cuttings of Tetrastigma hemsleyanum Diels et Gilg from Huaiyu Mountain,in this study,the chlorophyll contents,photosynthetic characteristics and chlorophyll fluorescence parameters of one-year seedlings and six-year cuttings of Tetrastigma hemsleyanum Diels et Gilg from Huaiyu Mountain were measured by Li-6400 photosynthetic instrument and SPAD-502 plus portable chlorophyll meter.The results showed that there was no significant difference in chlorophyll contents between one-year seedlings and six-year cuttings of Tetrastigma hemsleyanum Diels et Gilg from Huaiyu Mountain;there were significant differences in net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2)concentration(Ci)and stomatal limitation(Ls)between one-year seedlings and six-year cuttings,but there were no significant differences in transpiration rate(Tr),water use efficiency(WUE)and instantaneous carboxylation rate(CUE).Under the condition of light,the difference in maximum quantum yield of PSⅡ(F_(v)/F_(m))between one-year seedlings and six-year cuttings was extremely significant,but there were no significant differences in saturation pulse excitation maximum fluorescence value(F_(m)’),minimum fluorescence value(Fo’)and capture excitation energy efficiency(F_(v)’/F_(m)’).Under the condition of shading,there were significant differences in F_(v)/F_(m)and PSⅡpotential activity(F_(v)/Fo)between one-year seedlings and six-year cuttings,but there were no significant differences in Fo and F_(m).The photosynthetic efficiency of six-year-old cuttings was stronger than that of one-year seedlings,and photosynthetic efficiency was related to Gs,Ci,Ls,F_(v)/F_(m)and F_(v)/Fo.