An Efficient In Vitro Regeneration and Conservation Protocol of Rauvolfia serpentina (L.) Benth. Ex Kurz - An Endangered Medicinal Plant

Abstract

In the present study, a well-structured in vitro protocol for direct organogenesis was developed using Murashige and Skoog medium, with nodal and shoot tip explants, to achieve rapid clonal multiplication without an intervening callus phase. Explants were cultured on MS medium supplemented with varying concentrations and combinations of auxins (NAA, IAA, and IBA) and cytokinins (BAP and Kinetin). The response was evaluated in terms of shoot initiation percentage, shoot length, and number of shoots per explant, multiplication percentage with shoot length and number of shoots per explant, and root initiation response. The most effective treatment for direct shoot initiation was MS medium supplemented with BAP and Kinetin (1.0 mg/l-5.0 mg/l). The best initiation percentage was achieved in apical shoots compared to nodal explants at a low Kinetin concentration (1.5 mg/l), for multiplication on MS medium fortified with BAP (1.5 mg/l-5.00 mg/l) in combination with Kinetin (0.5 mg/l) and IBA (0.5 mg/l), which induced a high frequency of multiple shoots per explant. Rooting was achieved on MS liquid medium with NAA (0.5mg/l-2.0mg/l) in combination with IAA and IBA 0.5 mg/l. In vitro-raised shootlets were harvested, treated with IAA and IBA (1.0 mg/l and 1.5 mg/l) for a specific duration, and transplanted to pots containing a media mixture (Vermiculite and cocopeat @ 1:1), and studied for ex vitro rooting efficiency.