In vitro multiplication and rooting of guaco.

Abstract

Aiming at determining a protocol for the micropropagation of the guaco, Mikania glomerata Spreng, lateral buds were removed from wild plants, established in vitro, multiplied and utilized in experiments. For the multiplication, nodal segments removed from plants kept in vitro were inoculated in MS medium (Murashige and Skoog, 1962), with 0.0; 1.0; 2.0; 4.0, and 8.0 mg.L^-1 of BAP (6-benzylaminopurine) and 0.0 and 1.0 mg.L^-1 of IAA (indolacetic acid). For the rooting, stem segments with 2 to 3 buds and approximately 3 cm long were inoculated in MS medium with different concentrations of macro salts (25, 50 and 100%) combined with different concentrations of IAA (0.00; 0.25; 0.50, and 1.00 mg.L^-1). Within 60 days, 100% of the explants had emitted new buds and the highest average number of buds emitted per explant was verified in treatments with 1.0 to 4.0 mg.L^-1 of BAP. There was a significant reduction in the average number of buds emitted per explant in the presence of IAA. For the rooting experiment, 100% of the explants emitted roots in 60 days. The average number of roots per explant was significantly higher in the presence of IAA, demonstrating no statistical difference between the different concentrations used. In the different concentrations of MS medium, the average number of roots emitted per explant showed no difference. Concerning the burgeoning emission, in this experiment, the average number of buds emitted per explant was higher in the medium with 50% of concentration of MS salts and absence of IAA.