An efficient regeneration system and steviol glycoside analysis of Stevia rebaudiana Bertoni, a source of natural high-intensity sweetener

Abstract

Stevia is a natural, zero-calorie, intensively sweet extracted from the leaves of Stevia rebaudiana. Its sweet taste derives from a group of compounds known as steviol glycosides. In this study, an efficient micropropagation protocol for S. rebaudiana was developed for possible commercial implementation using Murashige and Skoog (MS) basal medium without plant growth regulators for most of the process. Direct shoot formation was achieved after cultivation of nodal segments on MS medium with or without plant growth regulators (benzyl amino purine [BAP], kinetin [KIN]) at various concentrations (0.1, 0.5, 1.0, or 2.0 mg L −1 ). Although all treatments produced two shoots per explants after 3 wk of culture, high concentrations of KIN and BAP (1.0 or 2.0 mg L −1 ) induced more callus formation. Rooting was achieved on MS medium containing 0.25 mg L −1 indole-3-acetic acid (IAA), which produced 8.1 roots per shoot after 3 wk of cultivation. After acclimatization of the regenerants in a portable greenhouse for 3 wk, all regenerants and seedderived seedlings were transferred to field conditions for 16 wk. Steviol glycoside contents (% leaf dry weight) did not differ between leaves collected from regenerants and seed-derived plants. Rebaudioside A content ranged from 4.7 to 5.0% (w/w), while stevioside ranged from 6.4 to 6.9% (w/w). There was no significant difference between the two sampling periods (late vegetative and flowering stages) for the plants grown in the field. In this study, a cost-effective in vitro regeneration protocol was established that enables efficient, large-scale in vitro production of S. rebaudiana for field cultivation.

Micropropagación de Gynerium sagitatum Aubl. cvs “criolla”, “costera” y “martinera”

“…On the other hand, in vitro cultivated plants grow under low light intensity that results in a deficient chloroplast development and incompetence for photosynthesis activity; therefore, during adaptation to Ex vitro conditions sunlight should be increased gradually to avoid plant loss and induce new leaf formation to acquire full photosynthetic competence. Energy required for new leaf development is obtained from energetic reserves store in Shoots organs such as stem and leaves, developed in vitro [45,46,47,48,49,50]. In the present research, micropropagated shoots, with and without adventitious roots, were transferred to Ex vitro conditions in a shadehouse with fog irrigation.…”

Cold tolerance of diverse stevia cultigens under controlled environment conditions

“…Stevia is a source of non‐caloric sweetening compounds and has economic potential in the global sweetener market. The agricultural cost of this crop is high even though demand is increasing globally (Yücesan et al., 2016). There has been limited research on chilling tolerance of stevia, but if available, the trait would help expand production into temperate areas.…”

Synthesis and production of steviol glycosides: recent research trends and perspectives

“…Therefore, plant material obtained through in vitro culture is used most often to grow S. rebaudiana. It creates a potential for a rapid mass production of planting material (Yadav et al 2011;Pande and Gupta 2013;Yücesan et al 2016;Rosales et al 2018). Although it is very labour and cost-intensive, it results in a cultivation of plants with desirable characteristics.…”

“…Considering time as an important factor for the large-scale production of plantlets, micropropagation seems to be irreplaceable. Yücesan et al (2016) have optimized an efficient micropropagation protocol for the rapid multiplication of S. rebaudiana plants through which more than half million of plants can be produced from the single node within 6 months.…”