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

Abstract

BackgroundElephant 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.ResultsAn 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.ConclusionDevelopment 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.

Micropropagation of Opuntia and Other Cacti Species Through Axillary Shoot Proliferation: A Comprehensive Review

“…Combining sodium hypochlorite with ethanol appeared to be more effective to neutralize the exogenous microbiota of several cacti species; thus, this procedure has been widely employed (Estrada-Luna et al, 2008 ; Bhau and Wakhlu, 2015 ). In Coryphantha elephantidens , three-step disinfection was used for surface sterilization of young shoots, that is, thorough washing with tap water and 1% of detergent, a 1 min soaking in ethanol (70:30 v/v), and immersion in sodium hydrochloride for 15 min (Bhau and Wakhlu, 2015 ). The aseptic culture of Opuntia robusta cladodes was obtained by soaking in a biocide solution (comprising 3 mg/L benlate, 3 mg/L captan, 1 ml/L previcur, 0.5 g/L amoxicillin, and 0.4% of ketoconazole) before the application of hypochlorite solution.…”

“…Numerous micropropagation techniques have been applied such as regeneration through somatic embryogenesis, regeneration through direct or indirect organogenesis, and in vitro grafting ( Figure 2 ). Those methods have been used for several species of cactus such as Mammillaria, Cereus, Hylocereus, Echinocereus, Astrophytum, Stenocactus, Schlumbergera, Coryphantha , and Copiapoa (Wakhlu and Bhau, 2000 ; Papafotiou et al, 2001 ; Mohamed-Yasseen, 2002 ; Al-Ramamneh et al, 2006 ; Lema-Rumińska and Kulus, 2012 ; Lema-Rumińska et al, 2013 ; Bhau and Wakhlu, 2015 ; Chornobrov and Bilous, 2021 ; Ivannikov et al, 2021 ). The regeneration through direct or indirect organogenesis appeared to be the most important and reliable method of in vitro propagation with about 80% of the conducted work on cacti ( Figure 3 ).…”

“…Several disinfecting agents were applied for cacti surface sterilization, such as sodium hypochlorite (present in commercial bleach and other reagents), which has been widely used; however, its efficiency remains low. Combining sodium hypochlorite with ethanol appeared to be more effective to neutralize the exogenous microbiota of several cacti species; thus, this procedure has been widely employed (Estrada-Luna et al, 2008 ; Bhau and Wakhlu, 2015 ). In Coryphantha elephantidens , three-step disinfection was used for surface sterilization of young shoots, that is, thorough washing with tap water and 1% of detergent, a 1 min soaking in ethanol (70:30 v/v), and immersion in sodium hydrochloride for 15 min (Bhau and Wakhlu, 2015 ).…”