Impact of Stevia rebaudiana Culturing in Liquid Medium: Elevation of Yield and Biomass, Mitigation of Steviol Glycosides

An efficient micropropagation system is developed by culturing nodal segments containing the axillary shoot buds on liquid Murashige and Skoog (MS) medium. Direct shoot and root formation are highly effective in both solid and liquid MS media without any plant growth regulators (PGRs). Interestingly, a significant difference in yield is obtained between solid and liquid cultures. It is revealed that a relatively higher amount of plant biomass is obtained after culturing for 4 weeks in a liquid MS medium. However, the shoots produced on solid MS medium produce a remarkable decline in all physiological parameters. On contrary, the bioactive steviol glycosides (rebaudioside-A and stevioside) content is higher in shoots grown in solid MS on a comparative basis, which could be compensated by higher yield. After hardening off, all the regenerants are effectively grown in the field with a negligible loss (<1 %), and steviol glycosides spectra is again obtained by conducting high-performance liquid chromatography (HPLC) analysis after 10 weeks of the plantation. This method has great potential to be applied on large scale in bioreactors.