Effects of basal media and some physical parameters on micropropagation of stevia (Stevia rebaudiana Bertoni)

Stevia (Stevia rebaudiana Bertoni) is a cross-pollinated plant whose seed vigor is poor. Therefore, the vegetative propagation approaches like in vitro culture techniques could be the best choice for mass and true-to-type production of stevia plantlets. This study was aimed to evaluate the effects of basal media (MS, B5 and LS) and physical parameters such as light (55 and 110 μmol m-2 s-1) and temperature (22, 25 and 27ºC) on in vitro culture of stevia. The nodal segments were cultured on basal media containing various combination of BAP and IAA or IBA. The ANOVA showed significant differences (P≤0.05) among treatments on micropropagation of stevia. In another experiment, the effect of mT (0.5, 1, 1.5 and 2 mg/l) was also compared with the best treatment from the first experiment. It was found that mT at 1 mg/l was the best concentration. The genetic stability of micropropagated plantlets relative to the mother plant was achieved by AFLP marker using 12 selected primers. In this study, 231 reproducible bands around 50-500bp were scored, indicating similarity of in vitro plantlets with the donor.