In vitro Multiple Shoot Regeneration from Nodal Explants of Stevia rebaudiana (Bert): An Antidiabetic Medicinal Plant
M. Thiyagarajan
Department of Biotechnology, Periyar University, Salem-11, TN
P. Venkatachalam
Department of Biotechnology, Periyar University, Salem-11, TN
*Author to whom correspondence should be addressed.
Abstract
A simple, rapid and large scale in vitro propagation method for Stevia rebaudiana has been established. Shoots were induced from nodal explants of field grown Stevia plants on MS medium fortified with different concentrations of BAP (0.5-2.0 mg/l) alone or in combination with 0.5 mg/l Kinetin. After two weeks of culture, multiple shoots emerged directly from the nodal explants. The highest frequency of shoot bud regeneration was noticed on MS medium supplemented with 1.0 mg/l BAP. Microcuttings dissected out from the in vitro proliferated shoot clumps were cultured on half-strength MS medium containing different concentrations of NAA (0.1 to 0.5 mg/l) and full strength MS medium fortified with different concentrations of NAA and/or IAA (0.5-2.0 mg/l) for rooting. Of the two auxins used, NAA at 0.4 mg/l was found to be the best concentration for maximum percent of root initiation. The rooted plantlets were successfully transferred into plastic cups containing sand and soil in the ratio of 1:2 and subsequently established in the greenhouse. The protocol developed for plant regeneration from nodal explants of Stevia rebaudiana may be suitable for large scale in vitro propagation of this important antidiabetic medicinal plant.