Effects of Lighting Cycle on Caladium Plantlets Grown under Ventilated and Airtight Culture Vessels in Relation to Net Daily CO2 Uptakes.

Abstract

Caladium plantlets were cultured in vitro under a long lighting cycle (16 hr light/8 hr dark) and a short lighting cycle (2 hr light/1 hr dark). When gas exchange between the inside and outside of the culture vessel was allowed, the short lighting cycle enhanced growth, but when the culture vessel was airtight, the lighting cycle had no effect on growth. The estimated net daily CO2 uptake under the short lighting cycle is greater than that under the long lighting cycle only when gas exchange occurs between the inside and outside of the vessel. These results demonstrate that the enhancement of growth by the short lighting cycle is due to an increase in the amount of available CO2 resulting from the reduced escape of CO2 from the vessel.