Micropropagation of Centella asiatica (L.), a valuable medicinal herb

A protocol is described for rapid and large-scale in vitro clonal propagati on of the valuable medicinal herb Centella asiatica (L.) by enhanced axilla ry bud proliferation in nodal segments isolated from mature plants. Althoug h bud break was dependent on BA supply, the synergistic combination of 22.2 muM BA and 2.68 muM NAA induced the optimum frequency (91%) of shoot forma tion as well as shoot number (4 to 5 shoots per node). Subculturing of noda l segments harvested from the in vitro derived axenic shoots on the multipl ication medium enabled continuous production of healthy shoots with similar frequency. MS medium supplemented with 6.7 muM BA and 2.88 muM IAA was fou nd most suitable for shoot elongation. Rooting was highest (90%) on full-st rength MS medium containing 2.46 muM IBA. Micropropagated plants establishe d in garden soil were uniform and identical to the donor plant with respect to growth characteristics. This micropropagation procedure could be useful for raising a stock of genetically homogenous plant material for field cul tivation.