Advances in Biological Research 4 (4): 211-216, 2010 ISSN 1992-0067 © IDOSI Publications, 2010 Corresponding Author: S. Karuppusamy, Department of Botany, The Madura College, Madurai-625 011, Tamil Nadu, India 211 Rapid in vitro Multiplication and Plant Regeneration from Nodal Explants of Andrographis neesiana: A Valuable Endemic Medicinal Plant S. Karuppusamy and K. Kalimuthu 1 2 Department of Botany, The Madura College, Madurai-625 011, Tamil Nadu, India 1 Department of Microbial Biotechnology, School of Biotechnology, 2 Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India Abstract: A rapid and efficient method for the large-scale propagation of an endemic medicinal plant, Andrographis neesiana Wight, through in vitro culture of nodal explants obtained from 30-d-old aseptic seedling has been developed. High frequency direct shoot proliferation was induced in nodal explants cultured on Murashige and Skoog’s medium supplemented with thidiazuron. Amongst the various cytokinins tested (BAP, kinetin, thidiazuron and 2-isopentyl adenine), thidiazuron proved to be the most effective. The shoot forming capacity of the nodal explants was influenced by the thidiazuron concentration (1-12.5 μM) and the optimal response was observed at 10 μM thidiazuron, which induced an average of 34 shoots in 94% of the cultures within 4 wk. Significant differences were recorded in terms of average number of shoots per explant (8.6-34.1) among the different concentrations of thidiazuron investigated. Concentrations of all cytokinins tested reach a level that can be considered above the optimum level, as marked by a reduced frequency of shoot proliferation. The multiple shoots obtained on various concentrations of thidiazuron failed to elongate even after transfer to hormone-free MS medium. Elongation of the induced shoots was achieved on MS basal medium supplemented with 1.0 μM GA within 2 wk. A proliferating shoot culture was established by repeatedly 3 subculturing the original nodal explants on shoot multiplication medium after each harvest of the newly formed shoots. The explants retained their morphogenic potential even after three harvests. Therefore, in 90 d, about 60-70 shoots were obtained from a single nodal explant and the nodal explants from primary shoots further regenerated equivalent number of shoots, depicting their high frequency regeneration potential in A. neesiana. Rooting was best induced in 94% of shoots cultured on MS medium supplemented with 2.5 μM indole-acetic acid (IAA), within a wk. The plantlets were successfully transferred to soil after hardening with a 92% survival rate. The system is rapid: the initiation of shoot buds to the transplanting of regenerants to soil is completed in 8-9 wk. Key words: Andrographis neesiana % Axillary proliferation % Micropropagation % Medicinal plant % Nodal explants INTRODUCTION neesiana [2]. The high demand for its flavone glycoside Andrographis neesiana Wight (Acanthaceae), is an A. paniculata by the pharmaceutical industries is endemic to Peninsular India, used as a herbal medicine by largely met by extraction of the compound from wild local communities. It is laxative, bitter and overcomes populations; however, the commercial exploitation of difficulty in breathing, burning sensation, cough, edema, this compound is hampered due to its limited availability. thirst, skin diseases, syphilitic ulcers, worms, acidity and Andrographis neesiana is a potential alternative liver complaints [1]. Two new flavonoids, 2',4',6',2,3,4- source of andrographalide. The heavy demand of hexamethoxychalcone and 5-hydroxy-7,2',5'- andrographolide in Indian as well as international markets trimethoxyflavone together with a known flavone has motivated Indian farmers to start commercial glycoside, echioidinin 5-O-beta-D-glucopyranoside were cultivation of this medicinal plant [3]. Conventional isolated from the whole plant of Andrographis propagation of this species is limited to vegetative means, andrographolide which is originally extracted from