作　　者： ; ; ; ;

机构地区： 上海植物园

出　　处： 《生态环境学报》 2010年第4期908-912,共5页

摘　　要： 桂花Osmanthus fragrans是我国城市园林建设中的重要树种,在上海居住区绿化中应用频度高达98.88%。目前对桂花的研究主要集中在栽培、种植和养护方面,但对其光合和蒸腾特性的研究较少。在自然条件下使用LICOR-6400光合测定仪测量了冬季和夏季桂花的净光合速率[Pn/(μmol.m-2.s-1)],以及蒸腾速率[T/(mmol.m-2.s-1)]、胞间CO2浓度[Ci/(μmol.L-1)]、气孔导度[GS/(mol.m-2.s-1)]等生理因子,以及气温(t/℃)、相对湿度(RH/%)、光合有效辐射[PAR/(μmol.m-2.s-1)]等环境因子的日变化。对桂花净光合作用与各种生理因子和环境因子的关系进行了分析,对桂花冬季和夏季净光合速率以及对高低温的适应策略进行了探讨。结果表明,随着气孔导度和蒸腾速率的增大,净光合速率也逐渐升高,但由于气孔调节的局限,净光合速率在达到最高值后又有所下降。冬季,桂花的光合作用效率降低,但其通过扩大对光适应范围,充分利用正午最适的光温条件来维持一定的净光合速率和固碳量。夏季,桂花通过午休现象和大量的蒸发降温来避免高温高光带来的伤害。冬季和夏季桂花的光合固碳能力相差不大,但夏季的桂花的水分利用效率远低于冬季。 As an important species of plant used in urban landscape construction in China,Osmanthus fragrans is deployed in up to 98.88% in the greening of Shanghai residential areas.Present studies of Osmanthus fragrans are focused on its planting,cultivation and conservation,but that on photosynthesis and transpiration is sparse.Diurnal Variation of Net photosynthetic rate of Osmanthus fragrans under natural condition was measured by using LICOR-6400XT portable photosynthesis system in winter and in summer.And transpiration,intercellular CO2 concentration,stomatal conductance,air temperature,relative humidity,and photosynthetically active radiation were also measured at the same time.The paper analyzed the relation among net photosynthetic rate,physiological factors and environmental factors,and discussed the difference of net photosynthetic rate between in winter and in summer and the adaptive strategies to air temperature.The results were as follows.With the increased of T and GS,Pn increased gradually.And when it got the limitation of stomata regulation,Pn got the maximum and then deduced slightly.Efficiency of photosynthesis was lower in winter than in summer.By enlarging the adaptation range of light and fully using the optimum temperature and light at noon,Pn and fixed carbon content maintained at a high level.The hurt of High temperature and high light was avoided by Midday depression of photosynthesis and high transpiration in summer.The ability of carbon fixation had few differences between that in winter and in summer,and the water use efficiency in summer was much lower than that in winter.

关 键 词： 净光合速率 蒸腾速率 胞间 浓度 气孔导度 固碳

领　　域： [生物学]