中文摘要：

叶片和树皮绿色组织是杨树两类重要的光合组织,分析其光合特征对温度升高的响应能够全面了解这一植物在适应气候变暖过程中的光合生理变化。本研究设置3个温度梯度（白天温度/夜间温度）23℃/18℃,28℃/23℃及33℃/28℃,分别从光合作用、叶绿素荧光特性等方面研究杨树（Populus alba×Populus berolinensis）叶片与树皮绿色组织对温度升高的响应及二者存在的差异。研究结果表明,随着温度升高,树皮绿色组织和叶片叶绿素含量没有发生明显变化,但树皮绿色组织叶绿素a/b的值随着温度升高明显降低。温度升高对叶片和树皮绿色组织的光合作用产生重要影响,叶片净光合速率（P_n）、光合效率（PE）、叶片气孔导度（G_s）及蒸腾速率（T_r）随着温度升高显著增强,但水分利用效率（WUE）却显著下降。树皮绿色组织净光合速率和光合效率具有和叶片相一致的反应,随着温度升高明显增强,但其它光合气体交换指标未发生显著变化。叶片和树皮绿色组织叶绿素荧光参数对温度升高响应基本一致,光系统Ⅱ实际光化学效率（Φ_（PSⅡ））、光化学淬灭（qP）、电子传递速率（ETR）及非光化学淬灭（NPQ）在33℃处理均表现为明显地降低,但二者光系统Ⅱ最大荧光效率（F_v/F_m）随着温度升高没有发生降低现象。本研究的研究结果表明气孔因素是导致杨树树皮绿色组织和叶片P_n随着温度升高而增大的主要原因。

英文摘要：

Leaf and bark chlorenchyma are two kinds of important photosynthetic tissues for poplar.Their responses to elevated temperature in photosynthetic parameters will be useful for photosynthetic physiological changes of poplar during global warming.We studied the changes of photosynthesis and chlorophyll florescence in leaf and bark chlorenchyma of poplar with three temperature treatments of 23℃/18℃,28℃/23℃ and 33℃/28℃（light/dark period）.The chlorophyll content of bark chlorenchyma and leaf were hardly affected in different temperature treatments.However,the values of chlorophyll a/b in the bark chlorenchyma decreased significantly by increasing the temperature up to 33 ℃.The rising temperature produced important influences on photosynthesis in leaf and bark chlorenchyma.The net photosynthetic rate（P_n）,photosynthetic efficiency（PE）,stomata conductance（G_s） and transpiration rate（T_r） of leaf and bark chlorenchyma significantly enhanced,but water use efficiency obviously declined with rising temperature.Leaf and bark chlorenchyma chlorophyll fluorescence showed similar response to elevated temperature.Except for the maximum photochemical efficiency（F_v/F_m）,actual photochemical efficiency（Φ_（PSⅡ））,photochemical quenching（qP）,non-photochemical quenching（NPQ） and photosynthetic electron transport rate（ETR） obviously decreased.Our results showed that stomatal factors mainly resulted in Pn increase of poplar bark chlorenchyma and leaf with elevated temperature.