九节龙光合速率与生态因子的日变化研究

利用Li-6400便携式光合作用测定系统对九节龙的光合速率的日变化进行了研究。结果表明:九节龙叶片净光合速率的日变化趋势表现为"双峰"曲线,其次高峰和最高峰分别出现在10:00和14:00,表现出有明显的"光合午休"现象,且导致其"光合午休"的主要原因为孔因素。相关分析和回归分析表明,九节龙光合速率的主要影响因子为气孔导度。此外,九节龙叶片光能利用率和水分利用效率与光合有效辐射呈极显著或显著负相关关系,即光合有效辐射越强,其叶片光能利用率和水分利用效率越低,说明九节龙叶片利用弱光的能力比较强。

Study on the diurnal variation of net photosynthetic rate and the eco-physiological factors of Ardisia pusilla

The diurnal variation of net photosynthetic rate of Ardisia pusilla and the correlation with its eco-physiological factors were investigated by using Li-6400 portable photosynthesis system. The results showed as following: the diurnal variation of net photosynthetic rate of A. pusilla in sunny day varied with double peak curve, showing obvious midday depression, and the peaks occurred at 10: 00 and 14: 00, respectively, and the first peak was lower than the second one. Correlation analysis and regression analysis showed that the dominantly influencing factor of net photosynthetic rate of A. pusilla was stomatal conductance.Light use efficiencyand water use efficiency were decreased with the increase of photosynthetically active radiation, which indicated that A. pusilla has rather greater potential to utilize poor light.