济南市校园6个绿化树种光合荧光特征比较初探

利用GFS-3000便携式光合仪、Mini-PAM便携式调制叶绿素荧光仪，研究了6种济南市校园绿化树种的光合荧光特征. 结果表明，龙爪槐和日本樱花净光合速率日变化曲线为单峰型，其他4种为双峰型曲线，双峰型曲线的光合午休由非气孔限制因素引起；龙爪槐和日本樱花单峰型的净光合速率对应着双峰型的气孔导度和蒸腾速率，在减少水分丧失的同时不降低同化能力. 随光照的增强，6个树种的最大荧光产量、有效量子产量均下降，非光化学淬灭上升，但物种间各参数变幅不同. 对电子传递速率的光响应曲线进行拟合，分析6个树种对光能的适应和利用能力，结果显示，贴梗海棠与金钟花能适应高光，但光能利用率较低；木兰、日本樱花和紫荆对高光敏感，但适宜光强下光能利用率较高；龙爪槐对光能的适应和利用能力居中. 6个树种主要光合荧光参数与环境因子的相关分析表明，环境因子与光合荧光参数间存在相关关系，但不同物种间存在差异.

Photosynthetic fluorescence characteristics of six greening tree species on university campuses in the city of Jinan

Photosynthetic fluorescence characteristics of six typical greening tree species on the university campuses in the city of Jinan were studied by utilizing the GFS-3000 portable gas exchange fluorescence system, Mini-PAM photosynthesis yield analyzer and CI-203 laser area meter under natural condition. The results show that diurnal courses of net photosynthetic rate of Sophora japonica var. and Prunus yedoensis display a single-peak pattern, whereas the four others show a two-peak pattern. Midday depressions of photosynthesis of these four species are caused by non-stomatal limitation. Diurnal courses of stomatal conductance and transpiration rate are a two-peak pattern for the first two species, which can lower the water loss without lessening the unisonous ability. All Fm-and ΦPSII are reduced, while qN and NPQ are raised with the PAR enhancement in the six species. The parameter ranges are different between these species. The photo response curve of ETR to PAR is fitted to analyze the adaptation and utilization abilities to light energy. The results show that Chaenomeles speciosa and Forsythia viridissima can adapt to high irradiance while their photosynthetic efficiency is low. Conversely, Magnolia liliflora, Prunus yedoensis and Cercis chinensis are sensitive to high irradiance while their photosynthetic efficiency is higher under the appropriate irradiances. The adaptation and utilization abilities to the light energy are moderate in Sophora japonica var. Based on the analysis of the photosynthetic fluorescence parameters and the environmental factors of these six tree species, the correlated relationship between them was obtained with the differences that exist between different species.