Differential Response of Leaf and Stem Explants to Growth Regulators and Direct Organogenesis of Baby Rubber Plant (Peperomia obtusifolia)

In vitro plant regeneration of Peperomia obtusifolia was successfully achieved via direct organogenesis from explanted leaf tissues. Multiple adventitious shoots were efficiently developed from 78% and 68% leaf explants cultured on Murashige and Skoog (MS) medium supplemented with 1 and 2 mg L−1 6benzylaminopurine (BAP) (on average; > 16 and 20 shoots/explant), respectively. In contrast, kinetin was inefficient compared to BAP, as few shoots developed after two months of incubation on MS medium plus 2-5 mg L−1 kinetin (on average; 30 roots/explant) compared to those cultured in the presence of 1-5 mg L−1 indole-3acetic acid (IAA) or 1 mg L−1 indole-3-butyric acid (IBA) (on average; 11-20 or 23 roots/explant, respectively). In contrast, 1-3 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) induced the development of many stunted thick roots with little callus. Callus was then proliferated, and was used for establishment of cell suspension cultures, which could have potential applications in further cell biology and biotechnology studies of this species.