In vitro Callus Regeneration of Caralluma bhupenderiana Sarkaria - An Endangered and Endemic Medicinal Plant

An effective in vitro callus regeneration protocol was standardized for the endangered, endemic succulent plant Caralluma bhupenderiana Sarkaria. Explants from healthy stem segments were cultured on Murashige and Skoog (MS), (1962) medium, Gamborg’s B₅ (B₅) and Woody Plant Medium (WPM) supplemented with 2,4-D 3mg/l for callus induction. Of all the media tested, MS medium with 2,4-D demonstrated the best callus response. Effect of different concentrations of auxins (Indole 3- Acetic Acid, Naphthalene Acetic Acid, Indole 3- Butyric Acid and Indole 3- Propionic Acid and 2,4-Dichlorophenoxy acetic acid) on callus induction was examined. However, 2,4-D (2mg/l) elicited the best callus induction. Plant regeneration was examined on MS medium fortified with 2,4-D (2mg/l) supplemented with various concentrations of cytokinins (Benzyl-6-adenopurine and Kinetin; 0.1 -0.4mg/l). Although significant shoot numbers were observed under the influence of 2mg/l 2,4-D and 2 mg/l BAP, the effect was profoundly increased upon second subculture in the same medium. The propagated shoots were kept for rooting on ½ strength MS medium supplemented with 0.1 mg/l NAA. Complete plants were developed and matured with a mean number of 12.06 ± 0.06 and root mean length of 3.00 ± 0.02. All the plantlets were acclimatized in the shade net house with a survival rate of 70%. The regenerated plants did not show any immediate notable phenotypic variation. The in-vitro protocol developed in the current study helps in the bulk production of Caralluma bhupenderiana and could be a good alternative non-conventional technique for conservation of rare and endemic species.