In vitro growth of Cattleya nobilior Rchb. f.: culture media, sealing systems and irradiance

Some factors may influence the in vitro culture of native orchids, especially the culture medium, sealing system and light condition. This study aimed to evaluate the addition of banana pulp and peel in the formulation of culture media, sealing system and irradiance, in the in vitro growth of Cattleya nobilior Rchb. f. A completely randomized design was used in a factorial scheme with five culture media [Murashige & Skoog supplemented or not with banana pulp or peel (100 or 200g L-1)], two light conditions [3,000 K LED lamps (43 μmol m-2 s-1 or 86 μmol m-2 s-1)] and two sealing systems (natural and conventional ventilation), with six replicates of one vial each. The plant height, diameter of the largest pseudobulb, length of the largest root and of the largest leaf, fresh weight and number of leaves, roots and shoots were evaluated. The use of both the banana pulp and peel as additives in the culture medium formulation promoted the C. nobilior growth. The natural ventilation system increased the plant height, pseudobulb diameter and leaf length, while the conventional system promoted tillering