<i>In vitro</i> plant regeneration of wintergreen (<i>Gaultheria fragrantissima</i> Wall.): Assessment of multiple nutrient formulations and cytokinin types

Abstract

A rapid clonal micropropagation protocol of <i>Gaultheria fragrantissima</i> Wall. (Ericaceae), an important medicinal plant from which wintergreen oil is extracted, has been developed. Mature plants collected from the field and <i>in vitro</i> raised juvenile seedling were used as source, and node and apical shoot were used as explants. Different basal media (MS, WPM, RM & MRM) supplemented with cytokinins (BA, Kin and 2iP) at a range of various concentrations have been investigated for multiple shoot induction. The 3 cytokinins induce shoot regeneration from nodal cuttings of <i>in</i> <i>vitro</i> raised seedlings in all the media. Optimum shoot induction occurred on MRM (modified rhododendron medium) supplemented with 2iP. After the first 3 cycle of culture with cytokinin, the shoots proliferated on cytokinin free basal medium. Subculturing the multiple shoots by separating into clumps of 5 shoots on MRM produced an average of 25 new shoots per culture within 8 wk. The <i>in vitro</i> raised microshoots were successfully rooted on half-strength basal MRM. Of the different substrates (sand, soil and leaf mold) studied for weaning, sand was the ideal substrate with 80% survival. Irrigation with half-strength MRM increased the survival rate and promoted the growth of the plantlets. Over 1000 plantlets were successfully weaned.