3种七叶树属植物叶片气体交换特征和叶绿素荧光特性比较

Comparison of Leaf Gas Exchange and Chlorophyll Fluorescence Parameters in Three Species of Aesculus Linn.

在自然条件下,测定了中华七叶树(Aesculus chinensis)、黄花七叶树(A.octandra)和大花七叶树(A.hybrida)植物叶片的气体交换参数和叶绿素荧光参数,并对其进行比较。结果表明,3种植物的光补偿点差异较大,其中中华七叶树最低,为12.53μmol.m-2.s-1、明显低于其它2个种(分别为36.11和46.41μmol.m-2.s-1);3种植物的光饱和点也存在较大差异,其中中华七叶树为1 475μmol.m-2.s-1;明显高于其它2个种(分别为1 366.67和1 025μmol.m-2.s-1);3种植物的最大净光合速率同样存在显著性差异,其中中华七叶树为9.47μmol CO2.m-2.s-1,显著高于其它2个种(分别为5.91和2.30μmol CO2.m-2.s-1),说明了中华七叶树具有较强的光合能力。中华七叶树的表观电子传递速率(ETR)为55.800,分别是黄花七叶树和大花七叶树的1.33、1.44倍;中华七叶树的PSⅡ总的光化学量子产额(Y ield)为0.470,分别是黄花七叶树和大花七叶树的1.21、1.15倍;中华七叶树的光化学淬灭(qP)为0.975,分别是黄花七叶树和大花七叶树的1.10、1.10倍。3项荧光指标在不同树种之间差异性达显著水平,说明中华七叶树具有较高的电子传递活性和光能转化效率。

The gas exchange and chlorophyll fluorescence parameters in leaves of three broadleaved tree species including Aesculus chinensis, A. octandra, A. hybrida were determined under field conditions. The results showed that light compensation point is different in three speciec, light compensation point in A. chinensis is lower （12.53 μmol·m^-2·s^-1） than other two speciec （respectively 12.53, 36. 11, 46.41μmol·m^-2·s^-1） ; Light saturation point is different in three speciec, Light saturation point in A. chinensis is highter （1 475 μmol·m^-2·s^-1） than other two speciec （respectively 1 366.67,1 025 -1μmol·m^-2·s^-1 ） ; Maximum net photosynthetic rate is different too, Maximum net photosynthetic rate in A. chinensis is higher （9.47 μmolCO2·m^-2·s^-1 ） than other two speciec （respectively 5.91,2.30 μmolCO2·m^-2·s^-1）. indicating that A. chinensis had higher photosynthetic capacity and stronger utilization ability for light energy. The electron transport rate（ETR）, PS Ⅱefficiency（Yield） photochemical quenching （qP） in the leaf were much higher in A. chinensis than in A. octandra and A. hybrida. These results indicated that the quantum yield of PS Ⅱ electron transport and the efficiency of primary conversion of light energy of PS Ⅱ.