Plant regeneration through somatic embryogenesis in medicinally important Centella asiatica L.

High-frequency somatic embryogenesis and plant regeneration was achieved on callus derived from leaf (petiole and lamina) and internode explants of Centella asiatica L. Growth regulators significantly influenced the frequency of somatic embryogenesis and plant regeneration. Calluses developed on Murashige and Skoog (MS) medium fortified with 4.52 muM 2,4-dichlorophenoxyacetic acid (2,4-D) or 5.37 muM alpha-naphthaleneacetic acid (NAA), both with 2.32 muM kinetin (Kn), were superior for somatic embryogenesis. Callus developed on NAA and Kn-supplemented medium favored induction and maturation of embryos earlier compared to that on 2,4-D and Kn. Embryogenic callus transferred from NAA and Kn-supplemented medium to suspension cultures of half-strength MS medium with NAA (2.69 muM) and Kn (1.16 muM) developed a mean of 204.3 somatic embryos per 100 mg of callus. Embryogenic callus transferred from 2,4-D and Kn subsequently to suspension cultures of half-strength MS medium with 2,4-D (0.45 muM) and Kn (1.16 muM) developed a mean of 303.1 embryos per 100 mg of callus. Eighty-eight percent of the embryos underwent maturation and conversion to plantlets upon transfer to half-strength MS semisolid medium having 0.054 muM NAA with either 0.044 muM BA or 0.046 muM Kn. Embryo-derived plantlets established in field conditions displayed morphological characters identical to those of the parent plant.