Abstract:
Withania ashwagandha, belonging to the family
Solanaceae, is an important medicinal herb of India with
restricted geographic distribution. It is a rich source of
withaferin A (WA) and other bioactive withanolides. In the
present study a rapid in vitro mass propagation protocol of
W. ashwagandha was developed from nodal explants. Nodal
explants were cultured on MS medium supplemented with
various concentrations and combinations of plant growth regulators
(PGRs). The highest number of regenerated shoots per
ex-plant (33±2.7) and highest WA (13.4±1.15 mg/g of DW)
production was obtained on MS medium supplemented with
5.0 μM 6-benzyladenine (BA) and 1.0 μM Kinetin (Kn). In
vitro raised shoots were further rooted on half-strength MS
medium containing 2.0 μM Indole-3-butyric acid (IBA) and
analyzed forWA production. The rooted plantlets when transferred
to poly bags in the greenhouse showed 90 % survival
frequency. Levels of WA were higher in the in vitro and ex
vitro derived shoot and root tissues as compared to field
grown mother plants. In an attempt to further maximize WA
production, shoot cultures were further grown in liquid MS
medium supplemented with 5.0 μM 6-benzyladenine (BA)
and 1.0 μM Kinetin (Kn). Root cultures were grown on half
strength MS liquid medium fortified with 2.0 μMof IBA.WA
production in the liquid cultures was significantly higher compared to the static composition of the same media. This
protocol, first of its kind in this plant, can be successfully
employed for conservation, proliferation and large-scale production
of WA. The regenerated plants can also be used in
traditional medicine as an alternative to naturally collected
plants.
