CO2倍增对鼓槌石斛光合作用特性的影响

研究高浓度CO2对鼓槌石斛光合作用的影响,对鼓槌石斛野生资源保护和开发利用具有重要的科学意义。CO2加倍处理后(30 d),利用气体交换技术和叶绿素荧光技术测定鼓槌石斛净光合速率、蒸腾速率、水分利用效率和叶绿素荧光等参数。结果表明:高浓度CO2使鼓槌石斛净光合效率(Pn)、胞间CO2浓度(Ci)和水分利用率(WUE)升高,而气孔导度(Cond)和蒸腾效率(Tr)降低;通过慢速荧光诱导动力学曲线得出鼓槌石斛最大光化学效率(Fv/Fm)变化不显著,实际光化学效率(Yield)和电子传递速率(ETR)升高,光化学淬灭系数(qP)显著上升,而非光化学淬灭系数(qN)显著下降。表明鼓槌石斛在未来高CO2和干旱环境条件下将具有良好的适应能力和生长优势。

Effects of doubled atmospheric CO2 concentration on photosynthesis of Dendrobium chrysotoxum

The purpose of this study is to research the photosynthetic response of Dendrobium.chrysotoxum to doubled CO2 concentration,which is important scientific significance to the protection and utilization of D.chrysotoxum.Leaf gas exchange and chlorophyll fluorescence paramters were measured with the treatment of doubled atmospheric CO2 concentration(30 days).The paramters of leaf gas exchange showed that net photosynthesis rate(Pn),intercellular CO2 concentration(Ci),water utilization efficiency(WUE) increased,and the stomatal conductance(Cond) and transpiration(Tr) decreased with the treatment of doubled CO2 concentration.The results of chlorophyll fluorescence paramters showed that the maximal photochemical efficiency(Fv/Fm) didn’t vary significantly,actual PSⅡ efficiency(Yield) and relative rate of electron transport(ETR)decreased,photochemical fluorescence quenching coefficient(qP) increased significantly and non-photochemical quenching coefficient(qN) decreased remarkably.These suggest that D.chrysotoxum is of great adaptability and growth advantage to drought and elevated CO2 concentration of the climat environment in the future.