In vitro micropropagation and microrhizome induction of curcuma comosa roxb

Abstract

This study was conducted to determine the effects of plant growth regulators on in vitro propagated plantlets and microrhizome inductions of Curcuma comosa Roxb. for an efficient development of plant regeneration. In vitro sprouted shoots (2 cm length) of C. comosa were incised in longitudinal section and subcultured on MS media supplemented with 3 mg/L BA for shoot multiplication and plant regeneration. Subsequently, the regenerated plants were transferred to MS medium with various concentrations of plant growth regulators; BA (1, 3, 5 mg/L), kinetin (1, 3, 5 mg/L) and TDZ (0.5, 1, 1.5 mg/L). The result showed that MS medium supplemented with 3 mg/L BA was the most effective in shoot induction with the significantly maximum average number of 2.11 shoot buds per responding explant. Moreover, MS medium supplemented with 1 mg/L BA produced the longest average of shoot bud explants (12.99 cm), while the basal MS medium induced the longest average of root multiplication (6.63 cm). Furthermore, microrhizome induction was produced under in vitro conditions derived young shoot buds upon transfer to MS medium containing various combinations of 1, 3 and 5 mg/L BA and 30, 60 and 90 g/L sucrose concentrations. The optimum combination in the induction of significantly highest average length of both stem (18.32 cm) and root (7.52 cm) multiplication was obtained on MS basal medium supplemented with 1 mg/L BA and 30 g/L sucrose for 4 weeks. Although microrhizome formation was not produced by the different amount of BA and sucrose in induction medium, starch accumulation was found at the base of the stem explants cultured on MS medium containing 60 and 90 g/L sucrose concentrations. Additionally, in vitro propagated C. comosa plantlets through microrhizome induction were grown under greenhouse conditions for 4 weeks and further developed into normal plants, resulting in successfully high survival rates of 66 – 100% in the cultivated C. comosa.