Effect of Elevated CO2 Concentration on Leaf Photosynthesis in Sanjiang-Deyeuxia angustifolia

Abstract

Deyeuxia angustifolia were grown under three different levels of CO2concentration conditions, 370μmol mol-1(ambient CO2), 550μmol mol-1(elevated CO2) and 700μmol mol-1(elevated CO2) respectively. We investigated the responses of photosynthesis and growth ofD.angustifoliaunder different CO2concentration conditions. Leaf photosynthesis and chlorophyll content were checked. The results showed that the values of net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2concentration (Ci), transpiration (E), chlorophyll content were influenced by the elevated CO2concentrations. The photosynthetic parameters changed in parallel with CO2enrichment. CO2enrichment in short term improved the photosynthetic ability of leaves, whereas the capacity was weakened under long-term elevated CO2concentration condition. The leaves ofD.angustifoliagrown under elevated CO2concentrations at the end of growth, had lower Pn, Gs, Ci, E and chlorophyll content than those grown and measuered under ambient CO2concentration. The results indicated thatD.angustifoliaappeared photosynthetic acclimation.