EFFECT OF LED-LIGHTS ON GROWTH AND SAPONIN ACCUMULATION OF CALLUS AND PLANTLETS OFPANAX VIETNAMENSIS HA ET GRUSHV. IN VITRO
In this study, callus and plantlets were cultured under six different lights: fluorescent lamp light (control), monochromatic blue LED (B), blue and red LED mixtures (B : R = 50 : 50, 30 : 70, 20 : 80) and monochromatic red LED (R) in orderto investigate the effects of LED-lights on callus induction and proliferation, plantlet growthand saponin accumulation of Panax vietnamensis Ha et Grushv. in vitro. Fresh weight, dry weight of callus were greatest (0.274 and 0.030 g, respectively) when leaf explants were cultured under the B:R = 50 : 50 blue and red LED light. Moreover, the B : R = 50 : 50 blue and red LED light enhanced proliferation of callus with highest fresh weight and dry weight (0.748 and 0.064 g, respectively). Fresh weight, dry weight, stem length and leaf area were highest in plantlets cultured under the B:R = 50:50 blue and red LED light. HPLC analysis results showed that different light sources had variable effects on saponin accumulation of callus and plantlets of Panax vietnamensis in vitro. The fluorescent light enhanced saponin accumulation of plantlets with highest saponin (0.2422 % Rb1 and 0.7081 % MR2) content.