Abstract

IN VITRO SELECTION AND PLANT REGENERATION OF PLECTRANTHUS AMBONICUS LOUR., AN IMPORTANT MEDICINAL PLANT

Souvagyalaxmi Sahoo*, Bhagyalaxmi Bhuyan, Kalpana Kanhar and Subhashree Satapathy

Abstract

An efficient plant regeneration protocol was developed for mass propagation of Plectranthus amboinicus from apical and lateral shoot explants on Murashige and Skoog‟s (MS) medium supplemented with 3.0 mg/l 6-benzylaminopurine (BAP), 5.0mg/l 1-napthalene acetic acid (NAA) and 3% (w/v) sucrose within 4 weeks of culture. The maximum numbers of shoot buds were obtained on MS medium supplemented with 3.0 mg/L BAP from lateral shoots within 6-7 weeks of sub culture. Inclusion of 1.0 mg/l gibberellic acid into the medium enhances the rate of shoot elongation and multiplication. Multiplication was higher when the cultures were incubated under continuous light rather than 16h photoperiod. MS medium supplemented with 1.0 mg/l BAP in combination with 5.0 mg/l NAA and 1.0 mg/l gibberlic acid showed best metabolic response with an average of 7.5 shoots per explants developed on 88% of cultures in 5-6 weeks. Repeated subculture on regeneration medium induces higher rate of shoot regeneration. Rooting was readily achieved upon transferring the micro shoots on to MS basal semi-solid medium supplemented with 0.5 mg/L IBA with number of roots per shoots (10-12.5) and root length (4.1 ± 0.2) cm after 4- 5weeks. Micropropagated plantlets were acclimatized and successfully grown in poly trays containing sand, vermiculite and soil (1:1:2) and covered with transparent plastic bags to prevent loss of humidity and acclimatized for a period of 3 weeks. About 98% micropropagated plantlets were hardened successfully. This study will help for propagation of quality planting material of P. amboinicus for commercialization required for therapeutic purposes.

Keywords: Plectranthus amboinicus, Micropropagation, Medicinal Plant, Plant Growth Regulator.