RESUMO
We used an OTC (open top chamber) system to study the effects of elevated CO2 concentration (atmospheric CO2 concentration + 200 #x03BC;mol·mol-1) on the growth and photosynthetic physiology of Hylotelephium erythrostictum. Elevated CO2 concentration decreased the leaf stomatal density of the upper and lower epidermis of H. erythrostictum by 16.1% and 16.7%, respectively. Elevated CO2 concentration increased the vascular bundle in leaves and the cell volume near the upper epidermis. Elevated CO2 concentration significantly increased the photosynthetic pigments content, net photosynthetic rate, stomatal conductance and transpiration rate of H. erythrostictum at night. In the evening of initial flowering stage, elevated CO2 concentration significantly reduced the malic acid content by 64.0%, while increased cellulose content by 20.8%. In the morning of full flowering stage, elevated CO2 concentration significantly increased the malic acid content by 27.0%, but had no effect on carbohydrate content. Elevated CO2 concentration increased the number of branches per plant, stem mass and total biomass of H. erythrostictum. Elevated CO2 concentration was beneficial to the growth of H. erythrostictum.
