In Vitro Propagation of Stevia (Stevia rebaudiana Bertoni): A Natural Sweetener from Nodal Segments

Abstract

Stevia (Stevia rebaudiana Bertoni) is a perennial shrub of the family Asteraceae. This species has a high commercial and medicinal value due to the presence of a low-calorie diterpene glycoside whose sweetening power in pure crystalline form is 300 times higher than sucrose. Propagation by seed presents heterogeneity problems in the population; therefore, in vitro culture offers a solution to this issue.

The material used for propagation consisted of nodal segments obtained from adult plants from the National Center for Agricultural and Forestry Technology. Cuttings of 10–12 cm length were used, disinfected with a 1.5% sodium hypochlorite (NaOCl) solution. They were then rinsed three times with sterile distilled water and cultured in MS medium (Murashige & Skoog, 1962) with 50% macronutrients and different cytokinin doses (without combinations): BAP (benzylaminopurine) and KIN (kinetin), at 0.0, 1.5, 2.0, 2.5, and 3.0 mg/l. From these, kinetin at 2.0 and 2.5 mg/l was selected for the multiplication stage.

The evaluated variable in the multiplication stage was the shoot production rate over three production cycles. The best results were obtained with the 2.5 mg/l dose, with no significant differences. The greatest plant height (13.5 cm) was achieved with 2.0 mg/l, and the highest number of leaves with 2.5 mg/l. These doses offer an economical alternative for micropropagation of stevia.