Shoot multiplication and direct organogenesis of an important medicinal plant Plumbago zeylanica L. (Plumbaginaceae).

Efficient micropropagation protocol was developed for Plumbago zeylanica L., a species threatened due to over exploitation for medicinal purposes and habitat destruction in Southern Peninsular India. Multiple shoot induction was more successful using nodes as explants on Murashige and Skoog’s (MS) medium supplemented with 1mg/L benzyl amino purine (BAP) . Shoots, when transferred to MS medium containing 0.2 – 0.5 mg/L gibberellic acid (GA3) showed variable elongation. Further, MS medium fortified with 1.5 mg/L BAP induced highest frequency of shoots through adventitious de novo organogenesis. Shoots developed were rooted on full strength MS medium with either α-naphthalene acetic acid (NAA), indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA). Optimum shoots and root multiplication were obtained within 8 weeks. In vitro derived plantlets were successfully weaned and transferred to soil and showed 90 % survival rate.