ABSTRACT:
The objective of this paper was to evaluate the effects of different honey concentrations in culture media, in comparison to sucrose medium, for the in vitro development of the epiphytic Encyclea cordigera orchid, in order to improve the process of propagation of the species. The in vitro germination was prepared on a reduced Murashige & Skoog (MS) medium. After 90 days, the seedlings were divided into different treatments, where they remained for another 90 days. Six treatments were set up (30g L-1 of sucrose; 15, 30, 45, and 60g L-1 of honey; and absence of any carbohydrates) in a completely randomized design. Plants were removed from the vials 270 days after the start of the experiment, and the number of roots, length of the largest leaf, length of the longest root, number of leaves, and fresh and dry masses were evaluated. Data concerning the number of leaves and roots were (x+1)1/2 transformed and subjected to an analysis of variance (ANOVA); the means were compared by a Tukey's test set at 5% probability. Medium containing 60g L-1 of honey proved to be superior to the sucrose medium traditionally used, favoring the in vitro growth and development of Encyclea cordigera. This medium can therefore be recommended for the propagation of this species, which is usually cultivated as an ornamental plant.
Key words:
Brazilian orchid; in vitro propagation; carbohydrate source
