BAP concentration and subcultive number in torch ginger multiplication

Abstract

The large ornamental potential of tropical flowers has stimulated the commercial cultivation of various species. Micropropagation is a viable alternate method of propagation, since it enables obtaining a higher number of seedlings with uniformity and pathogens free. The objective was to evaluate the in vitro multiplication rate of Etlingera elatior cv. Porcelana, using explants obtained from in vitro established seedling shoots, obtained from the 2nd subcultive. The explants were inoculated in MS culture medium containing different concentrations of BAP (0.0; 2.22; 4.44; 6.66; 8.88; and 11,10 μM), and the cultures maintained in a growth room with temperature 25.0 ± 2.0 °C under a photoperiod of 12 hours of light and light intensity of 30 μmol.m-2 s-1. The multiplication rate was monthly, according to the four subcultives, totaling 120 days. The experimental design was completely randomized, with four replications, analyzed in a factorial 4 x 6. The data were submitted to analysis of variance and regression. There were significant differences in subcultives and made for BAP concentrations used. For the first subcultive, the concentration of 2.22 μM of BAP afforded a rate of 4.06 sprouts per explant, already in the second and fourth subcultives, with the addition of cytokinin concentration was increased amount of sprouts reaching at a rate of 4.05 and 4.96 shoots/explant in the highest concentration of BAP. The results of the treatments evaluated indicate that the presence of BAP favored sprout emission. The concentrations of 2.22, 8.88 and 11.10 μM this cytokinin promoted the highest multiplication rates in the first, second and fourth subcultives, respectively.