Effects of Elevated CO2 Concentration on the Growth and Photosynthetic Characteristics in Guzmania 'Danis'

Abstract:

Studies on the growth and photosynthetic characteristics in Guzmania‘Danis’ were conducted in plastic greenhouse with top covered by shading net under elevated CO₂ (1 000±100 μmol mol_-1) and ambient CO₂(360±30 μmol mol_-1) conditions. The results showed that the plant height, leaf area, fresh and dry weightsof plants under elevated CO₂ were 120.19%, 119.22%, 177.91% and 161.04% of those under ambient CO₂, respec-tively, as determined after 90 days of experiment. Under elevated CO₂ condition, the net photosynthetic rate increased to l36％-259％ and chlorophyll content decreased to 33.9l％ in comparison with those under ambient CO₂ during the experiments． Elevated CO₂ stimulated the accumulation of soluble sugar an d starch， but declined the activity of glycolate oxidase in leaves，however，the activity of RuBPCase increased only slightly.