Evaluation of sucrose and GA, in an in vitro shoot culture of Alpinia purpurata( Zingiberaceae )

Alpinia purpurata is an ornamental plant species native to the Asia-Pacific with commercial potential due to its red inflorescence adapted to the northern Colombian coast; however, the lack of propagation protocols hinders commercial cultivation. To adjust a micropropagation protocol for clonal plant material production, the aim of this study was to evaluate the effect of sucrose and gibberellic acid (GA(3)) in the culture medium on the number of new shoots per explant, shoot length, root number, root length and number of leaves. Explants were cultured in semisolid MS (Murashige & Skoog, 1962) medium with sucrose (30, 45 and 60 mg/L) and GA(3) (0.0; 0.25; 0.5; 0.75 and 1.0 mg/L). A factorial experimental design with two factors was employed, with 15 treatments, 10 replicates per treatment and 150 experimental units distributed with a completely randomized design. Cultures were stored five weeks at 25 degrees C with a 12 h photoperiod (40 mu mol m(-2) s(-1)).Anova and Tukey's test allowed detecting the statistical effects of sucrose and GA(3) supply for all variables. An increase in sucrose concentration resulted in a higher number of shoots, while an increase in GA(3) induced longer shoots. Root length and leaf number decreased as GA(3) and sucrose increased.