In vitro Shoot Multiplication of Medicinally Important Plant Andrographis lineata Nees via Nodal Explants

Andrographis lineata Nees (Acanthaceae) is an endemic herb rich in flavonoids and diterpenoids which have pharmaceutical importance. Seedling explants source has not been studied for micropropagation and hence the present investigation has been taken up. An efficient protocol was developed for aseptic seed germination and in vitro shoot multiplication from different aseptic seedling explants. 30 days old aseptic seedlings grown on half strength MS medium were used as source of explants. Shoot tips, nodal segment, cotyledonary nodes, leaves, internodes and root segments were cultured on MS medium supplemented with BA 8.87 µM for testing for their responsivity. Nodal segments gave a maximum response when compared to other seedling explants and therefore were used in further experiments. Nodal segments were cultured on MS medium supplemented with various concentrations of cytokinins individually and in combination with auxins. Maximum number of 32.04 shoots per nodal explant were produced after 30 days of culturing on BA 8.87 µM + Indole-3-Butyric acid (IBA) 6.54 µM. Number of shoots further increased by sub culturing into fresh medium containing MS medium supplemented with BA 8.87 µM. Shoots were rooted on half strength MS medium and rooted plants were hardened in polycups containing sterile peat moss, farmyard manure and soil (1:1:1) with 75% survival rate.