Studies on in vitro regeneration from leaf explants of andrographis paniculata nees. — an important medicinal plant

Andrographis paniculata is a herbaceous plant containing the medicinally important secondary metabolite, andrographolide with pharmacological properties. The main aim of this study was to screen the best PGR combination and concentration and to develop an elite regeneration protocol for this plant species using leaf explants. Shoot gregeneration did not occur in any combinations and concentrations of PGR used in this study. However, callogenesis and rhizogenesis were observed on the PGRs used in this study. Root formation occurred directly from leaf midrib and petiole region and indirectly from leaf calli in MS medium containing combination of cytokinin and auxin with few exceptions as in the case of control, lmg/L BAP + 0.5mg/L NAA and 3mg/L BAP + 0.5mg/L NAA. Cytokinins have been reported to have a promoting effect in callougenesis and rhizogenesis. Phenolic content may also induce rhizogenesis. Further in-depth study with many more PGRs is needed to develop a protocol for direct shoot organogenesis from leaf explants of A. paniculata. 3mg/L KIN + 0.5mg/L NAA was the best PGR combination to induce adventitious root formation from leaf explants of A. paniculata. Averagely, approximate 12.07 roots of about 1.14cm long per explant was obtained. Phytochemical analysis of these roots may have a great scope to detect the medicinally important secondary metabolites.