Effects of Elevated CO2 on the Growth and Photosynthesis of Anthurium andraeanum

Abstract:

A nthurium andraeanum cv. Arizona was potted in three plastic greenhouses with top open. In each of the greenhouse, CO₂ was adjusted respectively to 360±30 μmol CO₂ mol^-1 （Control）, 700±100 μmol CO₂ mol^-1 （T1）,and 1 000±100 μmol CO₂ mol^-1 （T2）. Plant growth, net photosynthetic rate, activity of photosynthetic enzyme, and other physiological and biochemical characteristics were determined. The results showed that the plants grown under treatment T1 for 30 days increased in plant height, leaf area, and fresh weight by 12.8%, 2.39%, and 29.2%, respectively, and by 8.7%, 1.81% and 27.2% for treatment T2, respectively, compared to the Control. However, net photosynthetic rate （Pn） in treatments T1 and T2 measured under treatment conditions at that time were 27.0% and 33.8% higher, respectively, than those grown under the Control. Pn in T1 and T2 treatment measured in Control condition were also higher than that of the Control. Elevated CO₂ caused a marked increase in soluble sugar and starch accumulations in leaves, but significantly reduced their stomatal conductance and transpiratory rate, there is no evident difference in chlorophyll content between the Control and the treatment. In addition, elevated CO₂ had positive effect on Rubisco activity, and glycolate oxidase activity apparently decreased in leaves.