Ex-situ Conservation of the Rare and Threatened Medicinal Climber Corallocarpus epigaeus Rottler through In vitro Regeneration Method

Abstract

Aims: To develop in vitro propagation and callus induction protocol for regeneration and conservation of the rare and threatened medicinal climber, Corallocarpus epigaeus, which is widely acclaimed for high medicinal values. Place and Duration of Study: The plant was spotted on Nag Pahar hill forest of Ajmer district of Rajasthan, India. Its natural regenerative potential and exploitative practices by human beings were studied during November, 2012 to December, 2013. In vitro regeneration experiments were conducted during January, 2014 and January, 2016 at Regional Institute of Education, Ajmer. Methodology: The organogenic and callus induction potential of various parts of the plant            C. epigaeus were assessed through in vitro cultures. Murashige and Skoog`s (MS) media supplemented with various concentrations and combinations of 6-Benzyladenine (BA), Indole-3-acetic acid (IAA), α-Naphthaleneaceticacid (NAA), and Indole-3-butyric acid (IBA) were used  for enhanced axillary branching, callus induction, and rooting of microshoots. Acclimatization of rooted plantlets and their successful establishment to the soil conditions were also studied.     Results: An efficient plant regeneration system has been developed through enhanced axillary branching which was initiated from nodal segments cultured on MS medium supplemented with various concentrations of BA, and IAA in combination. The maximum number of shoots 8.41±0.29 with average length of 6.29±0.32 cm per explant was achieved in MS medium containing 0.5 mg/L BA and 2.0 mg/L IAA. The best callus induction from stem and leaf explants was obtained on MS medium containing 2.0 mg/L (BA) and 0.5 mg/L NAA. Rooting of microshoots was achieved on half-strength MS medium supplemented with 1.0 mg/L IBA. Well developed plantlets transferred to the soil conditions showed 67% survival. Conclusion: The methodology is reliable and highly beneficial for ex situ conservation, maintenance of in vitro biodiversity and multiplication of the Great Root for commercial production of tubers of diverse pharmacological properties.