Rapid in vitro propagation of Lucas aspera Spreng. A potential multipurpose Indian medicinal herb

Lucas aspera Spreng. (Lamiaceae) is an important medicinal plant, producing saponins with pharmacological and medicinal applications. The present study was carried out to develop an efficient protocol for plant regeneration in internode segments of L. aspera wild plants, and demonstrate that, the in vitro regenerates are useful alternatives for the year-round availability of plants for the production of saponins. Intemode segments from wild plants were surface sterilized and cultured on MS medium supplemented with different concentrations of cytokinins, BAP/kinetin/2-iP (0.5-5.0 mg L-1) either alone or in combination with auxins, IAA/IBA/NAA (0.1-1.0 mg L-1) for shoot regeneration. Multiple shoots (6.9 shoots/explant) were induced in the explants with higher frequency (93.4%) on medium supplemented with 1.5 mg/L BAP and 0.1 mg L-1 NAA combination. Highest frequency of rooting (83.2%) was observed on half-strength MS medium augmented with 0.1 mg L-1 IBA. The plantlets were successfully acclimatized and established in the greenhouse. Clonal fidelity of regenerates was verified by biochemical marker analysis, molecular marker analysis and phytochemical profile analysis, and thus confirmed as true-to-types of wild plants. The present in vitro propagation protocol would be an alternative method not only for rapid propagation of this traditional medicinal plant, but also alternative means for ensuring the year-round availability of its saponins.