An easy hardening off method for micropropagated Guarianthe skinneri (Orchidaceae) plantlets

Abstract

This study reports an easy protocol for hardening off plantlets of the tropical orchid Guarianthe skinneri, which is a culturally relevant plant species in several countries of the Central American region. In order to increase the post vitro survival rate of micropropagated plants, we included a “preparation step” before transferring the plants from the laboratory to the greenhouse. This preparation step (two weeks of duration in Dalla Rosa and Laneri or KO7 medium) consisted in the ventilation of the culture vessel. Results showed that, in comparison with the control treatment, ventilation of the culture vessel (aperture of 88 mm2) yielded the greatest survival (90%) and best appearance (3.4 on a hedonic scale of 0.0 to 4.0) of plants. Results are explained with base in the hydric relations of the plants with their microenvironment.