Effect of MS and L2 Medium on Callusing and Regeneration From Nodal Explants of Asclepias curassavica- (L)

The present study demonstrates an efficient protocol for in vitro mass propagation of A. curassavica through direct as well as indirect regeneration. The effect of MS and L2 media supplemented with various concentrations and combinations of growth regulators has been studied. The growth regulators used include BAP and kinetin (cytokinins) and IAA, IBA, NAA and 2, 4-D (auxins). MS media proved better for callusing than L2 media and callus mediated shoot organogenesis was obtained by sub culturing the organogenic callus obtained from leaf explants on MS + 2 mg/L NAA + 1mg/L BAP+0.5 mg/L KN on to a fresh medium fortified with 1 mg/L BAP+ 0.1 mg/L GA3 lacking NAA. Among the two different media (MS and L2) tested, L2 medium proved superior to MS medium in terms of shoot multiplication and shoot length. Nodal explants showed better organogenic response than shoot tip explants. Among nodal explants basal nodal explants produced more number of shoots than terminal nodes for shoot morphogenesis. Among the two different cytokinins tested in MS media BAP proved better than KN for improving shoot number and shoot length in combination with different auxins. Among the two different cytokinins tested in L2 media KN proved better than BAP for improving shoot number and shoot length either individually or in combination with different auxins. Highest number of shoots was obtained from nodal explants cultured on L2 media containing 3 mg/L KN in combination with IAA. Hence L2 media proved to be effective for organogenesis while MS yielded better callusing and can be employed for in vitro mass propagation of A. curassavica.