Rapid in vitro multiplication and conservation of Garcinia indica: A tropical medicinal tree species

A simple and efficient method has been developed for rapid regeneration of plantlets via adventitious bud differentiation on mature seeds of Garcinia indica (Thouars) Choisy, a medicinally important facultative apomictic tropical tree species. High frequency direct shoot proliferation was induced in seed segments cultured on Murashige and Skoog's medium supplemented with cytokinins (BAP, kinetin and TDZ) alone and in combination with auxin (NAA). Amongst the various combinations used, BAP proved to be the most effective. Multiple shoots formed within 4-5 weeks of culture. The shoot forming capacity of the seeds was influenced by the BAP concentration tested (5-50 μM) and optimal response was observed at different concentrations (12.5-50 μM) in different genotypes investigated. Significant differences were recorded in terms of percent response (27.78-100%) as well as average number of shoots per explant (3.49-57.67) among the four genotypes investigated. Elongation of the induced shoots was achieved on MS basal medium containing 0.2% activated charcoal. The induction medium had a profound effect on rate of bud elongation with shoots induced on lower concentrations of BAP showing as much as four-fold elongation within 4 weeks. Proliferating shoot cultures were established by repeatedly subculturing the shoot nodes on MS medium supplemented with 5 μM BAP. Maximum rooting (91.66%) occurred in shoots cultured on half-strength MS medium supplemented with 10 μM IBA. The plantlets were successfully transferred to soil after hardening; the time period from initiation of shoot buds to transplantation being 15-17 weeks. For in vitro conservation, the shoot cultures were maintained on medium supplemented with 0.5 μM BAP and the subculture duration could be enhanced up to maximum of 11 months.