1989 年 27 巻 1 号 p. 9-13
The measurements of CO2 and O2 concentration of in vitro atmosphere of cultured Caladium bicolor (C3 plant), Phalaenopsis hybrid (CAM plant) and Dendrobium phalaenopsis (CAM plant) were conducted under different day-lengths (continuous lighting, 16 hours and 8 hours) .
At the continuous lighting, the CO2 concentration in the vessel remained below 0.01%, that was at the level of CO2 deficiency for the cultured plants. And the O2 level ranged around 21.1%.
In the vessel of Caladium bicolor cultured under 16 hours or 8 hours day-length, the CO2 level continued to increase during the dark period and decreased immediately after lighting. Finally it attained to the level of the CO2compensation point of 0.005% a few hours after lighting.
In Phalaenopsis hybrid and Dendrobium phalaenopsis, CO2 uptake was observed in the middle of the dark period, but the CO2 level in the vessel increased again at the end of dark. These results indicate that the pools of organic acids had not developed and that the in vitro cultured CAM plants showed a little CAM activity.
On the other hand, the O2 level gradually decreased during dark period and increased during light period both in the C3 plant and in the CAM plants.