The influence of different concentrations of activated charcoal in the in vitro growth and rooting of Cattleya pumila Hook

Abstract

Cattleya pumila, a small ornamental endemic species in Brazil, is an orchid with easy in vitro germination but low rooting rates. Current analysis investigates the effects of the absence of activated charcoal and the presence of two concentrations of the same in the Kyoto culture medium on the species’s growth and rooting. Plants derived from tissue culture were inoculated in thirty 250 mL flasks with 50 mL of the culture medium, with 10 flasks for each treatment. They were evaluated randomly after 35, 50, 65 and 80 days of in vitro culture and in 50% of the samples. Results related to growth of roots, leaves, whole plants and weight of fresh matter were employed for the calculations of linear regressions. Results showed that the culture medium supplemented by 1 g L-1 of activated charcoal had the greatest increase for the variable root length, whereas the culture medium supplemented by 3 g L-1 had the best results for the other variables analyzed.