Abstract
By monitoring the utilization of sugars by petiole segments of Begonia×hiemalis cultured in medium containing the plant grwoth regulators, kinetin (1 ppm), NAA (1 ppm), the optimum time for beginning the CO2 enrichment treatment was established.
The total sugar concentration in the medium decreased rapidly after 40 days of culturing. The cessation of sugar depletion by the tissues after 60 days is attributed to the onset of photosynthesis by the plantlets. CO2 administration at this time promoted leaf development, whereas CO2 enrichment 10 to 20 days earlier halted the development of adventitious shoots. These observations suggest that the optimum period to begin CO2 enrichment to promote shoot growth and to enhance photosynthesis is about 60 days after the culturing the petiole segments.
