Micropropagation of a Thai medicinal plant for women's health, Curcuma comosa Roxb., via shoot and microrhizome inductions

We studied the effects of explant types, plant growth regulators, and sucrose concentrations on shoot and microrhizome inductions of Curcuma comosa Roxb., an important Thai medicinal plant for women's health. Explant types significantly affected shoot induction of the plant. The maximum shoot multiplication rate of 11.82 ± 1.03 shoots/ responding explant was obtained when culturing terminal bud explants on semi-solid Murashige and Skoog (MS) medium supplemented with 18.16 μ M thidiazuron for 8 weeks. Subsequently, they were transferred to a semisolid MS medium without plant growth regulators for 4 weeks. The regenerated shoots produced roots spontaneously. Rooted plantlets were successfully transferred to the soil. Microrhizome induction was significantly influenced by sucrose concentrations, but not by 6-benzyladenine (BA). Liquid MS medium with a combination of 17.76 lM BA and 50 g L ^-1 sucrose was optimal for microrhizome induction of C. comosa. After 12 weeks of culture, the microrhizome induction rate was 3.36 ± 0.44 microrhizomes/ responding explant. Starch accumulation in microrhizomes increased with higher sugar concentration and with longer duration of culture. The microrhizomes were allowed to germinate under greenhouse conditions and further developed into normal plants. The protocols established will be used for the production of uniform plantlets suitable for field plantation for the herbal industry.