Effects of growth factors on induction of callus and somatic embryogenesis Stevia rebaudiana Bertoni

Stevia rebaudiana Bertoni from Asteraceae family is a useful medicinal plant that prevents and cures diabetes, blood pressure, weight gain and tooth decay. Due to the sweetness and health of the sweet leaf, this plant is highly regarded in terms of economics and science. In order to investigate the characteristics of callus induction in stevia, a factorial experiment in a completely randomized design (CRD) with three replications was done. In order to create callus from a single node of this plant, it was cultured in MS medium containing hormone. Explants were cultured on Ms medium containing different concentrations of cytokinins and auxins. Results showed that the hormonesBAP (with concentrations 1 and 1.5 mg/L) and NAA (0.5 and 1.5 mg/L) were the effective ones on callus induction; after two weeks, the calluses reached about 0.5 cm. Somatic embryogenesis has served as a model to understand the physiological and biochemical events that occur during plant developmental processes as well as a component to biotechnological. The acquired calluses were transferred to the embryonic hormone containing somatic embryo for induction. Results showed that the hormones 2,4,5-T with concentrations (0.2 and 0.3 mg/L ) and kinetin with a concentration of 2 mg/L were the most effective ones regarding somatic embryogenesis. The results showed also that the composition, ratio, and concentration of growth regulators differed in the degree of callus induction and embryogenesis of the stevia plants.

Keywords:

Development , Growth factors , Callus , Somatic embryogenesis , Stevia rebaudiana