Microrhizome induction in Acorus calamus Linn. — An important medicinal and aromatic plant

An effective protocol for in vitro microrhizome induction was developed for Acorus calamus. The explants, rhizome axillary buds, were cultured on dual phase Murashige and Skoog (MS) medium consisting of agar solidified phase overlaid by liquid fraction of the same medium. In this study, the effects of indole butyric acid (IBA) and — naphthalene acetic acid (NAA) containing 2–10% (w/v) sucrose were examined on microrhizome induction. Best response was observed on the medium supplemented with 2.0 mg L−1 IBA and 60% sucrose under 16/8 hours light/dark photoperiod which produced the maximum rhizome fresh weight (0.82 g) and size (length 4.8 cm; diameter 0.55 cm) in 6 weeks. The microrhizomes had 7–8 buds which were developed independent of season and each segment sprouted into roots and shoots when transplanted to soil. This protocol can be adopted for various applications, viz., large scale production of propagules of elite cytotype, in vitro conservation of the microrhizome, synthesis of secondary metabolites and for studying the biosynthetic pathways of the bioactive molecules present in the rhizomes of this important medicinal and aromatic plant.