Plant Regeneration System for Osbeckiaoctandra (L.) DC: A Valuable Medicinal Plant

Abstract

Osbeckiaoctandra (HeenBovitiya), which is one of the most valuable ayurvedic medicinal and ornamental plants in Sri Lanka, is now threatened due to its overexploitation from their natural habitat. In order to produce high quality, disease-free and genetically identical plant materials in large scale, we developed a highly efficient in vitro clonal propagation system using leaf explants. The effects of three different concentrations of plant growth regulators (6-benzylaminopurine (BAP), 1-naphthaleneacetic acid (NAA), kinetin and incubation conditions on plant regeneration were investigated. Plant growth parameters were analyzed in 15 biological replicates using one-way ANOVA. Present study revealed that the highest number of shoots per leaf explant with 92.4% shoot induction rate was achieved when young mature leaf explants were cultured on Murashige and Skoog (MS) medium supplemented with 3 mg/L BAP and 0.5 mg/L NAA and incubated under dark conditions. When microshoots were separated and subcultured onto hormone-free MS medium containing high sugar content (4%), rapid shoot multiplication and a vigorous root development was detected under light conditions. The in vitro grown plantlets were successfully acclimatized and 89% of the regenerated plantlets survived. Our novel clonal propagation system will open new avenues for mass propagation of O. octandra plants for the pharmaceutical industry and improving their medicinal and ornamental characteristics through biotechnological tools.