Culture medium and agar substitutes for in vitro growth of orchids

Abstract

The in vitro culture is a technique that has allowed the spread of different species of orchids, but the slow growth of this group of plants, and the cost of the minerals and the gelling agent (agar) used in the culture media, can limit its application. The aim of this research was to understand the effect of the composition of the culture medium and the use of substrates as agar substitutes for in vitro growth of Laelia anceps Lindl. And Epidendrum sp. Adventitious buds of both species were cultured in vitro in different substrates mixtures (perlite, volcanic rock and coir) and agar with different concentrations of Murashige and Skoog basal salts (50 and 100%) and gibberellic acid (AG₃) (0 and 1 mg L^-1) to evaluate its length, number of leaves, number of roots and fresh weight in an experimental design with three factors and 15 repetitions, each repetition consisted in a flask with 5 adventitious shoots. The in vitro behavior was based on the genotype L. anceps Lindl. that responded better tan Epidendrum sp. Outbreaks grown on perlitevolcanic rock or coir-volcanic rock, and médiums with 50% salts and AG₃ showed no significant difference in terms of length, number of leaves, number of roots and fresh weight, with respect to those grown in agar, 100% salts without AG₃. The culture médium with diluted with salts without AG₃ and substrates as substitutes for agar, allowed the in vitro growth of L. plants anceps Lindl. And Epidendrum sp. plants with a significant 60% costs reduction.