In vitro production studies of Stevia rebaudiana Bertoni (Asteraceae)

The aim of this work was to assess the production possibilities of Stevia rebaudiana Bertoni via plant tissue culture techniques. Leaf and node explants were used for this purpose. Explant from leaves was found to be the best source for callus culture is leaf formation when MS is employed as basal medium supplemented with three different media plant growth regulators including 1 mg / L TDZ + 1 mg / L IBA, 0.1 mg / L IBA + 5 mg / L ZEA and 0.1 mg / L NAA + 0.5 mg / L BAP + 0.5 mg / L 2,4-D. In addition, 5 mg / L 2iP and 2 mg / L IBA were also used as monitoring callus development. In terms of callus formation, the most suitable plant growth regulator combination was 1 mg / L TDZ + 1 mg / L IBA. Dark and light illumination was also assessed and as a result, the former produced white and compact whereas the latter gave rise to green and friable calli. Stevial glucose was not found in the samples obtained from callus cultures. In addition, a shoot formation, e.g. direct organogenesis, was also studied. MS basal medium without growth regulators together with BAP (2.5-5-7.5 mg / L) and KIN (0.5-1-2 mg / L) were used for this purpose. MS without growth regulators was the most effective medium. When compared, KIN was also found to be better than BAP for healthy shoot formation. On the other hand the phenolic contents of samples were evaluated, and chlorogenic acid was found as major phenolic acid, which is especially higher in samples grown on MS media supplemented with 5 mg / L 2iP and 2 mg/L IBA.