Efficient In vitro Propagation and Optimized Multiple Shoot Induction of Caralluma bhupenderiana an Endangered Medicinal Plant

Caralluma bhupenderiana is one of the medicinally important species within the Apocynaceae family. Recent In vitro studies revealed its medicinal properties particularly antioxidant and anti-inflammatory activities. C. bhupenderiana is considered an endemic, as it faces threats from habitat loss and overharvesting for medicinal and culinary uses. These challenges should be addressed using micropropagation techniques. Our study focuses on standardizing the protocol for inducing multiple shoots under In vitro conditions. Stem explants of C. bhupenderiana were treated with various concentrations of surface sterilants (Sodium Hypochlorite, Mercuric Chloride, Hydrogen Peroxide) initially and cultured onto different nutrient media (Gamborg’s B5 medium, Woody Plant Medium & Murashige and Skoog medium). Within the tested chemicals, mercuric chloride (0.1% w/v) for 5 minutes exhibited a healthy shoot response (80%), and MS medium showed the highest shooting with 86.66% compared to others. Additionally, the MS media was supplemented with cytokinins (6-Benzylaminopurine-BAP and Kinetin-Kn) to optimize the shoot sprouting. Where BAP (3.0 mg/l) was found to be the best for inducing shoots with a mean shoot number of 4.66±0.14. Then MS media containing auxins (Naphthalene Acetic Acid, Indole-3-Acetic Acid, Indole-3-Butyric Acid, Isopentenyl Adenine and 2,4-Dichlorophenoxyacetic Acid) and BAP was tested to induce multiple shoots from single explant of C. bhupenderiana. The peak growth of 93.3% was shown by BAP (3.0 mg/l) + IBA (0.1 mg/l) with a maximum mean shoot number of 21.00 ± 0.07 and the longest mean shoot length of 6.75 ± 0.03 cm. Further, the regenerated shoots were sub-cultured onto half-strength MS media provided with auxins (IAA, IBA and NAA). Rooting with 100% was observed in ½ MS + NAA (0.1mg/l) with an optimal mean number of 12.06 ± 0.06 roots per shoot. 70% of the In vitro grown C. bhupenderiana plants were acclimatized.