Photosynthetic pigments and gas exchange of in vitro grown tobacco plants as affected by CO2 supply

Contents and functioning of photosynthetic pigments and gas exchange of Nic otiana tabacum L. leaves were studied in platlets cultivated in vitro under different CO2 supply. The plantlets were grown for six weeks either in gla ss vessels tightly closed with aluminium foil (G-plants) or in polycarbonat e Magenta GA-7 vessels covered with closures with microporous vents (M-plan ts). M-plants (better supplied with CO2) had higher contents of chlorophyll (Chl) a, Chl b, and beta-carotene, higher photochemical activities of phot osystem 2 and whole electron transport chain, and lower contents of xanthop hyll cycle pigments. Differences in Chi a fluorescence kinetic parameters b etween G-plants and M-plants were not statistically significant. M-plants h ad higher net photosynthetic rate, and lower transpiration rate and stomata l conductance than G-plants.