The results indicated that
CO2 enrichment was proper on the second day after transplantation. Petunia plantlets were used to conduct experiments
under PPFD of 80 lmol m2 s
1
, and CO2 concentrations of 350 ± 50 ll l1
, 650 ± 50 ll l1 and 950 ± 50 ll l1 as well
as medium moisture contents of 60%, 70% and 80%, with the result that plantlets grew better under CO2 concentration
of 650 ± 50 ll l1 than under the other two concentrations with all the different media water contents. Three