High-frequency callus organogenesis, large-scale cultivation and assessment of clonal fidelity of regenerated plants of Curcuma caesia Roxb., an important source of camphor

摘要

An efficient in vitro propagation protocol has been standardized for Curcuma caesia Roxb., an important source of camphor, using bud- and leaf-derived callus. The optimum response of 84 and 71 % callus induction was obtained when bud and leaf segment explants were cultured on Murashige and Skoog (MS) medium supplemented with 6.7 A mu M 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 2.7 A mu M naphthalene acetic acid (NAA). The white, friable, organogenic calli were subcultured on MS medium supplemented with 6.8 A mu M thidiazuron (TDZ) and 1.6 A mu M NAA for shoot induction. On this medium, 90 % of the bud-derived calli responded with an average number of 16.2 shoots per culture. Comparatively, bud-derived calli demonstrated a better regeneration response than leaf calli. In vitro rooting of shoots was also obtained on the regeneration medium. The rooted shoots were successfully hardened and transferred to field conditions. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analysis revealed no evidence of genetic variation in all 22 plants established from the callus with the parental plant, suggesting this protocol could be used for large-scale true-to-type propagation and multiplication of elite clones of C. caesia.