Optimization of photoautotrophic micropropagation conditions for sweetpotato (Ipomoea batatas (L.) Lam.) plantlets

Growth and net photosynthetic rate of sweetpotato (Ipomoea batatas (L.) Lam.) 'Beniazuma' plantlet in vitro were studied under photoautotrophic micropropagation conditions (without sugar in the medium and under 100 μmol m^-2 s^-1 PPFD and enriched CO₂ concentrations) with high number of air exchange of the vessel. The photoautotrophic growth under these conditions was enhanced as compared with that of the plantlets cultured under conventional conditions (with sugar in the medium and under 50 μmol m^-2 s^-1 PPFD and no CO₂ enrichment). The growth of the plantlets in a large vessel was greater with medium of hydroponic nutrient solution and vermiculite support under photoautotrophic conditions than with agar gelled medium under conventional conditions.