RESUMO
Objective: The in vitro mutation system of Stevia rebaudiana induced by ethylmethane sulfonate (EMS) was established, and the salt-tolerant mutants were identified by SRAP. Methods: S. rebaudiana plantlets were inoculated on MS media containing NaCl with different concentration to screen the salt-tolerant critical concentration. Plantlets were treated with EMS at different concentration and for different time periods, and EMS mutagenized stems were inoculated on MS medium containing critical NaCl concentration to screen the tolerant variants by SRAP markers. Results: The critical salt concentration of S. rebaudiana plantlets was 1.0%, and the suitable concentration and time of EMS were 0.8%-1.0% and 8-10 h. Among the screened 41 S. rebaudiana tolerant mutants by SRAP molecular markers, four were mutated at DNA level, and the mutation rate was 9.76%. Conclusion: The in vitro mutagenesis system of S. rebaudiana with EMS has been established, which provides a new breeding way for high-yield salt-tolerant S. rebaudiana.