A highly efficient in vitro propagation protocol for elephant tusk cactus: Coryphantha elephantidens (Lem.) Lem.

Background: Elephant tusk cactus Coryphantha elephantidens (Lem.) Lem. is an important attractive ornamental cactus. The plant produces offshoots from tubercles very rarely, and the seedlings exhibit slow growth and susceptibility to damping off. Slow growth and high demand in the cactus industry lead to finding an alternate fast propagation method. Results: An innovative in vitro technique based on axillary bud proliferation has been developed for an ornamental cactus C. elephantidens (Lem.) Lem. Four different explant types formed multiple shoots on Murashige and Skoog (MS) medium. Of the two cytokinins, 6-Benzylaminopurine (BAP) and Kinetin (KN), BAP proved to be more effective for multiple shoot induction and shoot growth from different explant types. Longitudinally cut stem explants, when cultured on MS medium supplemented with 6.6 μM BAP give maximum axillary shoot proliferation (12.4 shoots). Type of explant significantly influenced the micropropagation rate. Type of carbon source used in the medium imparted a profound effect on shoot growth and dry weight. The maximum dry weight gain of the shoot was observed with 9% sucrose. Conclusion: Development of an efficient micropropagation protocol which can be used to produce more than 10,000 rooted plantlets in 150 days from a single longitudinally divided shoot explant