The aim of this study was to evaluate the effect of different concentrations of activated charcoal in ½ MS (half concentration of macronutrients) culture medium under two light spectra on the in vitro growth of Cattleya loddigesii seedlings. Plantlets with approximately 90 days were subcultured under eight treatments, consisting of different active charcoal concentrations (0; 0.5; 1.0 and 2.0g L-1) in ½ MS medium combined with white and red light spectra. After 180 days of germination, biometric data, fresh weight, and the level of photosynthetic pigments were evaluated. Plantlets acclimatized in a greenhouse were evaluated for survival after 120 days. Total chlorophyll, chlorophyll a, and carotenoid concentrations were higher in treatments under white light, while red light promoted greater chlorophyll b, plantlets with fewer and shorter roots, and high ex vitro mortality. The addition of 2.0g L-1 of active charcoal to the culture medium and the use of white light provided greater development efficiency both on in vitro culture and ex vitro plant survival.
In vitro germination; luminosity; kinds of light; orchid; plantlets and ex vitro survival
