[Recovery of bromeliad photosynthesis after exposure to elevated CO2].

After exposed to elevated CO2 [T1: (600 +/- 40) micromol x mol(-1) and T2: (900 +/- 40) micromol x mol(-1)] for 150 days, Guzmania 'Luna' and Guzmania 'Denise' were transferred to ambient CO2 for 30 days to investigate the recovery of their photosynthesis and their key photosynthetic enzyme activities. The results showed that compared with that in CK, the net photosynthetic rate (Pn) of Guzmania 'Luna' in treatments T1 and T2 was decreased by 7.41% and 13.33%, respectively. The Pn of Guzmania 'Denise' in T1 was approached to CK, and that in T2 was higher than CK. After 30 days recovery, the accumulation of soluble sugar and starch in test bromeliads leaves decreased obviously, with the contents being close to those of CK. The rubisco and glycolate oxidase activities in treatments T1 and T2 had a decreased difference with CK, but were still lower than those of CK.