High frequency shoot regeneration and plant establishment of Rauvolfia serpentina: An endangered medicinal plant

Abstract

An efficient method was developed for high frequency shoot regeneration and plant establishment from nodal segment explants of Rauvolfia serpentina. Among the three different cytokinins (6-benzyladenine (BA), kinetin (Kin) and 2-isopentenyl adenine (2-iP)) tested as supplements to Murashige and Skoog (MS) medium, BA at 5.0 μM concentration was found effective in inducing multiple shoots. Effects of different medium (Murashige and Skoog (MS), Gamborg medium (B5), Schenk and Hildebrandt (SH) and Woody Plant Medium (WPM)) on in vitro regeneration were also evaluated. The highest frequency of shoot regeneration (90%) and maximum number of shoot (45.4 ± 3.2 per explants) with an average shoot length of 4.7 ± 0.21 cm were standardized on WPM supplemented with 5.0 μM BA along with 1.0 μM α-naphthalene acetic acid (NAA). In vitro regenerated micro-shoots rooted best on WPM supplemented with 1.0 μM NAA. Plantlets with well-developed shoot and roots, following acclimation in the greenhouse, were successfully established in field condition, and 90% of plants were survived. The regenerated plants were morphologically normal and did not show any immediate detectable phenotypic variation. The method developed can be successfully employed for large-scale multiplication and long-term in vitro conservation of R. serpentina. Key words: Nodal explants, plant growth regulators, in vitro, plant regeneration, micro-propagation.