Micropropagation of Stevia rebaudiana in temporary immersion systems as an alternative horticultural production method

Stevia rebaudiana, known as sweetleaf, produces a sweetener in its leaves due to the presence of steviol glycosides (stevioside and rebaudioside); however, its seed has germination problems, which is why various temporary immersion systems (TIS) have been studied for its production. The objectives of this study were to scale up the in vitro production of two S. rebaudiana cultivars using RITA®, BIT® and SETIS®, and to evaluate the production of biomass in the field. The studied cultivars were 'Morita II' and 'Silvestre'. The production stages of both cultivars were: in vitro, liquid medium (with three TIS: RITA®, BIT® and SETIS®), greenhouse and finally they were taken to the field. In each TIS, five different media were evaluated, varying in each one the concentrations of sucrose, calcium pantothenate and gibberellic acid. The treatments produced vigorous plants, a greater number of leaves and shoots, and a higher multiplication rate. Both cultivars had greater stem length in BIT. Under this same system 'Morita II' produced eight shoots per plant, while in SETIS only three. 'Silvestre' had two shoots per plant with the two TIS. In both cultivars, regardless of the TIS, greenhouse survival and foliage production in the field were very similar. Therefore, the selection of the material should be based on the content of steviosides and the adaptation of the cultivar to the planting site. All TIS evaluated allowed scaling-up plant production, and both materials are promising for planting.