Comparative Effects of Plant Growth Regulators on Callus Induction in Leaf Explants of Wedelia chinensis

Wedelia chinensis , a perennial herb of the family Asteraceae, is used traditionally in ayurvedic, siddha and Unani system of medicines. The plant has been extensively used in inflammations, helmintic diseases and liver disorders. This excessive pharmaceutical application has led to serious shortage of the plant in natural habitat. In vitro culture technique has been proved to be very effective for rapid propagation of rare plant species including medicinal plants. Callus induction and study of callogenic response to different plant growth regulators is a major step in production of phytoconstituents using invitro techniques. The present study was therefore undertaken with a view to develop an efficient and repeatable protocol for rapid production of callus cultures for the production of these phytochemical constituents. Leaf segments were used as explants and were cultured on Murashige and Skoog's (MS) medium supplemented with different concentrations of auxins (2, 4‐dichlorophenoxyacetic acid (2,4‐D), indole acetic acid (IAA)) alone and in combination with different cytokinins (6‐benzylaminopurine (6‐BAP), kinetin (Kn)). The callus obtained were friable and greenish white in colour. Maximum rate of callus formation was observed in media containing 1 mg/L 2,4‐D and 0.5 mg/L 6‐BAP.