EFFECTS OF CO₂ ENRICHMENT ON THE GROWTH AND THE PHOTOSYNTHETIC RATE OF IN VITRO CAULIFLOWER PLANTLETS

The effects of ventilation and CO₂ supply on the growth and photosynthetic rate of mixotrophic plantlets of cauliflower (Brassica oleracea L.) were investigated.
The in vitro plantlets were established in airtight vessels (C) and ventilative vessels with a gas permeable film (V) and grown for 15 days under 16 h photoperiod with fluorescent lamps (130 μmol· m^-2· s^-1) and 25°C air temperature.
High CO₂ concentration surrounding vessels (about 1200 μl· l^-1, Vco₂) was applied through experiments.
No difference was measured in shoot and root dry weight, total leaf area, and CO₂ and light saturated rate of photosynthesis between plantlets in treatments V and Vco₂ grown in the ventilative vessels.
Total dry weight, total leaf area, and maximum photosynthesis of the in vitro plantlets grown in V increased up to about 4, 2, and 2 times, respectively, greater than those grown in C. Also there were significant increases in both chlorophyll and total soluble protein contents in leaves of the plantlets in treatment V compared with the plantlets in treatment C with positive correlations between maximum photosynthesis and both chlorophyll and total soluble protein contents.
Promoting growth of the in vitro plantlets under ventilative conditions may be result of the enhanced photosynthesis rate in photoautotrophy because of the relieved CO₂ starvation for the in vitro plantlets during photoperiod.
Cauliflower mixotrophic plantlets in vitro grew rapidly and enhanced photosynthetic rate under ventilative culture conditions and these improvements of growth and photosynthesis were due to the increase in CO₂ concentration surrounding vessels.

Environmental Effects and their Control in Plant Tissue Culture

M. Abe, M. Kanechi, N. Inagaki, M. Taniguchi, S. Maekawa

Cauliflower, CO₂ enrichment, growth, photosynthesis, tissue culture

https://doi.org/10.17660/ActaHortic.1995.393.17