两种耐水湿树种光合作用及其影响因子初探

Study on Photosynthesis and Its Influencing factors of Two Types of Water Resistant Plants

利用Li-6400光合仪测定了水紫树、枫杨的光合特征参数,探讨了两个树种光合日变化规律,并对净光合速率与生理生态因子进行回归分析和通径分析,找出影响两个树种净光合速率的主要因子。结果表明:水紫树、枫杨的净光合速率日变化均呈单峰曲线,峰值均出现在11:00时;气孔导度值7:00时最高,后逐渐降低;胞间CO2浓度的日变化表现为早晚高午间低;气孔限制值呈单峰模型。经过回归和通径分析可知,水紫树影响光合速率的主要因子是气孔导度、胞间CO2浓度、大气水汽压亏缺和光合有效辐射,影响枫杨净光合速率的主要因子是气孔导度、蒸腾速率、大气水汽压亏缺和光合有效辐射,且各因子对光合速率的影响程度不同。

By using Li--6400 photosynthesis system, the photosynthetic characteristic parameters of two types of water resistant plants including Nyssa aquatica and Pterocarya stenoptera were measured. The daily change of photosynthetic rate, the net photosynthetic rate and the eco physiological factors were discussed, the regression analysis and the path analysis were also conducted. The results showed that： the curves of net photosynthetic rate （Pn） of one peak, which appeared at 11：00, the curves of stomatal conductance gradually reduced, the highest at 7：00. The curves of stomatal limiting value of one peak. According to regression and path analysis, it could be concluded that the impact factor and its extent about two willow species net photosynthetic rate showed significant differences, the Pn influencing factors for Nyssa aquatica were Cond, Ci, Vbdl and PAR;while for Pterocarya stenoptera were Cond, Tr, Vbdl and PAR.