In vitro multiplication of Oncidium leucochilum (Orchidaceae) in different culture system

Abstract

The objective of this work was to compare different systems on in vitro multiplication of Oncidium leucochilum. The treatments were two types of bioreactors: RITA® and BIB®, both with temporary immersion (30 min each 2 h) and the conventional culture in liquid medium. Culture medium was MS supplemented with 1 mg.L-1 BAP, 0.25 mg.L-1 NAA and 5 μL.L-1 Tween® 20, the pH was adjusted to 5.8. Cultures were kept in a growth room with 25±2°C, under cool white light (35 µM.m-2.s-1), with 16 hours of photoperiod. The experimental design was complete randomized with 3 replicates of 20 explants. After 45 days of in vitro culture was observed that explants cultivated in bioreactor BIB® showed higher shoot number per explant (6.56), higher fresh mass increment (5.7g), larger dry mass (0.59g) and aerial part height (1.87cm) compared to explants cultured at bioreactor RITA® and conventional culture. The bioreactor BIB® is a viable alternative, efficient and had lowest cost for in vitro multiplication of O. leucochilum.