Indirect organogenesis from stem derived callus of caesalpinia bonduc (l.) roxb– a medicinal plant of western ghats

An in vitro protocol was developed for multiple shoot induction via indirect organogenesis from the mature stem explants of Caesalpinia bonduc (L.) Roxb (Caesalpinaceae), a scrambling woody liana and medicinal plant. Callus was initiated from stem explants 15 days after inoculation, when 2, 4-dichlorophenoxyacetic acid (2, 4-D) was used alone at 0.25 to 3 mgL-1 on Murashige and Skoog (MS) medium. After 20-25 days on the same medium callus formation and shoot bud differentiation was noticed from the entire surface of explants .Callus induction was optimized at 2 mgL-1 2,4-D and 0. 2 mgL-1 6-benzyladenine (BA) in 96.66% of all explants. After culturing callus for 15 days on MS medium with 1-6 mgL-1 BA and 0.1–1 mgL-1 indole-3-butyric acid (IBA), small green protuberances formed over the entire surface of the callus which later developed into small shoots. 4 mgL-1 BA with 0.5 mgL-1 IBA was the optimal hormonal combination for multiple shoot organogenesis with a mean of 36.6 ± 1.17 shoots/explant and a mean shoot length of 7.09 ± 0.23 per callus-forming explant. Rooting of the small shoots was achieved on MS medium fortified with 0.2-2.0 mgL-1 IBA and optimized with 0.6 IBA mgL-1. Roots formed from the base of shoots after 3 weeks of culture and 80% of the regenerants could be acclimatized.