香茶菜和大萼香茶菜光合和叶绿素荧光特征的比较

Comparative Investigations of Photosynthetic and Chlorophyll Fluorescence Characteristics of Isodon amethystoides and I. sodon macrocalyx

香茶菜属(Isodon)植物多数含有二萜类化合物,具有重要的药用价值。香茶菜(Isodon amethystoides)和大萼香茶菜(I.macrocalyx)又是该属中常见的二种植物,本文比较了这两种香茶菜的光合和叶绿素荧光特性。结果表明:大萼香茶菜的最大净光合速率为11.50±0.09μmol CO2m-2s-1,光补偿点为17.25μmol.m-2.s-1,光饱和点约为1728μmol.m-2.s-1;香茶菜的最大净光合速率为9.59±0.19μmol CO2m-2s-1,光补偿点为7.65μmol.m-2.s-1,光饱和点约为1700μmol.m-2.s-1;香茶菜和大萼香茶菜均有比较明显的"光午休"现象,但是香茶菜的更为明显。两种香茶菜均属于耐阴植物,但是香茶菜,比大萼香茶菜更耐阴。经充分暗适应后的叶片叶绿素最大荧光产量(Fm)、最大光化学量子产量(Fv/Fm)、PSⅡ的潜在活性(Fv/Fo),大萼香茶菜的要大于香茶菜;叶绿素荧光参数与光强变化的关系分析表明,大萼香茶菜的PSⅡ实际的光化学反应量子效率(фpsII)、非循环电子传递速率(ETR)、非光化学猝灭系数和光化学猝灭系数要大于香茶菜,因此,香茶菜有相对较高的光能利用效率。

Most species of the genus Isodon are of important medical values. The species, Isodon amethystoides and I. macrocalyx, are widely distributed in Eastern China. In the present paper, their photosynthetic and chlorophyll fluorescence characteristics are comparatively investigated using LCA -4 portable photosynthesis and transpiration system （ADC, England） and Minor PAM （Waltz, German）. The main results are as follows （1） the actual maximal net photosynthetic rate, light saturation point and light compensation point of I. macrocalyx are 11.50 ± 0.09μ mol CO2 · m^-2 · s^-1, 1728 μmol m^-2 · s^-1, and 17. 25 μmol m^-2· s^-1 , respectively. While those of I. amethystoides are 9. 59 ±0. 19 μmol CO2 · m^-2 · s^-1 , 1700 μmol m^-2 . s , and 7. 65 μmol m ^ s , respectively （2） after sufficiently adapting to darkness, the chlorophyll fluorescence indices including Fv/Fo, andFv/Fm of I. maerocalyx are higher than those of I. amethystoides. The analyses on the relationships of chlorophyll fluorescence indices with light intensities show that the ФpsII, ETR, NPQ and qP of I. maeroealyx are all higher than those of I. amethystoides. Therefore, Isodon macrocalyx is relatively higher in light utilization efficiency in photosynthesis than I. amethystoides.