In-Vitro Mass Propagation of Withania Somnifera (L.) Dunal

Abstract

Withania somnifera (L.) Dunal (Ashwagandha), of the family Solanaceae is an important medicinal plant and a major source of alkaloid and steroid (withanolids), which is regularly used in pharmaceutical industries. The present study describes the procedure for micropropagation of W. somnifera. The morphogenetic responses of various vegetative parts (shoot-tip, node, root and leaf) were studied in MS medium supplemented with different concentrations and combinations of phytohormones. Seeds were pretreated with GA3 (50 and 100 mgl-1) for 24 hours and 80% germination was achieved. All the explants were taken from in-vitro germinated plant. Among the different explants tested, multiple shoot formation was achieved from shoot-tip and nodal explants in MS + 0.25, 0.5, and 1.0 mgl-1 kinetin. Nodal explants were selected for mass propagation protocol because: it formed maximum number of shoots. Shoots were started to differentiate after one week of culture and after 8 weeks an average of 16.25 shoots/explant were formed on MS + 1 mgl-1 kinetin. Increase in concentration of kinetin was most effective for callus formation. For further multiplication of shoot, adventitious shoots with callus at the base were sub cultured on MS + 0.5 mgl-1 kinetin and multiple shoots (14.25 to 14.5 shoots/culture) were protruded out. Auxins, (IAA, IBA and NAA) were supplemented in MS medium to induce rooting. Among these auxins, IAA at 0.5 mgl-1 was found to be the most effective concentration for rooting of in-vitro propagated shoots (50 roots/shoot). Rooted plantlets were transferred on the pot containing coco-pit, sand, sand-soil mixture (50% each) and coco-pit + garden soil mixture (50% each). Only few weeks of survival is recorded in last two combination of hardening medium.