Crescimento in vitro de Cattleya nobilior Rchb.f.: meios de cultura, sistema de micropropagação e irradiância

Abstract

This work was developed with the objective of evaluating the addition of banana pulp and peel in the culture medium formulation, the micropropagation 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, two light conditions and two sealing systems, with six replicates of one flask each. The culture medium used was Murashige and Skoog supplemented or not with banana pulp or peel. The flasks containing each culture medium were divided into two sets and submitted to two micropropagation systems, with the cultures being allocated under two irradiations provided by LEDs 3000K: 43 µmol m-2 s-1 or 86 µmol m-2 s-1, in an environment with controlled temperature and photoperiod (25±2 °C; 16 h). After 90 days of the subculture, the plants were removed from the flasks, washed and evaluated for leaf number, plant height, diameter of largest pseudobulb, number of shoots, number of roots, length of largest root, length of largest leaf and mass fresh. Both the use of the banana pulp and the banana peel as additives in the formulation of the culture media promoted the growth of C. nobilior. The use of the natural ventilation system promoted the increase in height, diameter and length of C. nobilior, while the conventional system promoted tillering. The supply of light bulbs for LED 3000K, independent of the irradiance, positively influences in vitro growth of C. nobilior.