Induction of Callus in Leaf Explants of Crinum americanum L. (Amaryllidaceae)

Amaryllidaceae include plant species that present alkaloids with analgesic, anti-cancer, anti-bacterial, anti-viral, anti-fungal and anti-malarial activities. Due to this pharmacological value, several species of this family have been widely studied and among them is White lilly, Crinum americanum. The objective of this work was to induce callogenesis on leaf explants of C. americanum cultivated in vitro for future production of alkaloids. Leaf explants were grown on a culture medium (solid) Murashige and Skoog (1962) supplemented with different concentrations and combinations of plant growth regulators, auxin 2,4-dichlorophenoxyacetic acid and cytokinin 6-benzylaminopurine and their effect on callogenesis assessed for percentage oxidation and explants responsive to callus induction. Callus formation started 10 days after hormone inoculation, and within 30 days after inoculation the best callogenesis and callus biomass growth were observed in medium containing 2.5 mg L-1 of 2,4-dichlorophenoxyacetic acid and 10 mg L-1 of 6-benzylaminopurine. The lowest percentage of oxidation was observed on explants cultivated on medium containing 5 mg L-1 of 6-benzylaminopurine and 2.5 mg L-1 of 2,4-dichlorophenoxyacetic acid. The calli obtained were compact and embryogenic. This work contributes not only to future studies on in vitro callogenesis of this species, but also to a possible protocol for the production of alkaloids of interest from cell suspension cultures produced in vitro. This is the first report of callus formation in Crinum americanum explants.