Preliminary study of the hormetic effect of nitrate and chloride of cerium on the micropropagation of Stevia rebaudiana Bertoni

Resumen

Objective: This study aimed to evaluate the effect of cerium nitrate and cerium chloride on morphophysiological and biochemical variables in S. rebaudiana In vitro.

Design/methodology/approach: S. rebaudiana explants were grown for 30 days on MS medium supplemented with cerium nitrate or chloride at 0, 10, 20, 30, 40 and 50 µM concentrations, respectively.

Results: It was observed that cerium nitrate at a concentration of 10 μM stimulated shoot proliferation (10.55 ± 1.11) and plant growth (12.12 ± 0.51 cm), whereas cerium chloride at the same concentration favoured plant height (13.25 ± 0.53 cm). Cerium nitrate at a concentration of 30 μM significantly increased chlorophyll content (0.957 ± 0.005 mg g^-1 FW). In addition, a hormetic effect was observed with both cerium salts, i.e., biostimulation at low concentrations and lethal toxicity at the maximum concentration evaluated (50 μM), showing a greater toxic effect with the chloride counterion.

Limitations on study/implications: This study constitutes a preliminary in vitr research; although cerium has a beneficial effect during the micropropagation of S. rebaudiana, its effectiveness must be evaluated through additional ex vitro studies.

Findings/conclusions: Controlled and adequate doses can be used to obtain the highest biostimulant effect on S. rebaudiana shoot proliferation In vitro.