Abstract
Rauvolfia serpentina (L.) Benth. ex Kurz., popularly known as Indian Snakeroot plant, belonging to Apocynaceae family, holds immense medicinal importance, owing to its rich source of multiple secondary metabolites such as ajmaline, ajmalicine, reserpine, and serpentine. To meet the constant demands for the key secondary metabolite (reserpine) by majority of the pharmaceutical industries, the present study assessed the effects of direct and indirect regeneration system on amelioration of reserpine accumulation in shoots of R. serpentina. In vitro multiple shoot cultures were established using shoot tip explants. Best results for shoot initiation, multiplication, and biomass production were obtained in case of Murashige and Skoog medium, supplemented with 1 mg/l N (6)-benzyladenine. The multiple shoots were then sub-cultured on cytokinin-auxin combination media for further proliferation. Highest shoot and leaf multiplication rates and the most enhanced biomass were obtained in case of 1-1.5 mg/l Kinetin + 0.2 mg/l α-naphthalene acetic acid (NAA). Callus induction and its subsequent proliferation was obtained using 1.5 mg/l 2,4-dichlorophenoxyacetic acid. The best indirect shoot regeneration with highest shoot and leaf proliferation from calli was observed in case of 1 mg/l thidiazuron + 0.2 mg/l NAA. Reserpine content estimation via HPTLC from in vitro shoots (direct regeneration) and calli (indirect regeneration) were recorded to undergo an almost three-fold and two-fold increment (respectively) in comparison to that of the mother plant. Thus, in vitro direct regeneration system proved to be more effective and efficient in ameliorating the reserpine content.