Micropropagation through apical shoot explants and morphogenic potential of different explants of Saussurea lappa: An endangered medicinal plant

Abstract

Saussurea lappa is a medicinal plant, which is used against a lot of diseases. Due to over exploitation for commercial and medicinal purposes, this plant is now endangered. Current study was carried out to develop a protocol for micropropagation and to determine morphogenic potential of different explants for callus induction of S. lappa, with the objective to develop plants in short time and large number. The explants were properly sterilized with 0.1% mercuric chloride for 1, 2 and 3 minutes. Maximum sterilization was observed with 3 minutes but decreased explants survival. However, 85% explants survived with 1-minute treatment. Benzyl amino purine and indolebutyric acid at 1.0 mg L 1 concentration produced 90% shoots and 93.66% roots respectively. Among the different explants, seedling and root explants were found more efficient in callus induction compared to other explants. Callus initiation occurred after 3 days of culturing of shoot and seedling followed by petiole (6 days) whereas lamina explants took 15-20 days. After 7 subsequent subcultures, the highest relative growth rate of 0.141 week-1 of callus was noted in seedling explants followed by root 0.098 week-1 and petiole 0.082 week-1 whereas lamina showed significantly low relative growth rate of 0.016 week-1. Tissue culture technique should be used for conservation of endangered medicinal plants such as Saussurea lappa.