Direct organogenesis from cold treated in vitro leaf explants of Stevia rebaudiana Bertoni

Abstract

Stevia rebaudiana is a perennial herb belonging to Asteraceae family and an excellent substitute of artificial sugar. Increasing demand of quality panting material has emphasized the need of rapid and mass multiplication through plant tissue culture technology in limited time duration. Sterilized in vivo leaves were used as leaf explants on different concentration of BAP, Kin and TDZ. In all media, shoot induction was not observed at any concentration from in vivo leaf explants. Cold treatment (4oC) of different time duration (0-72 hr) was applied on in vitro leaf explants and cultured on various concentration of TDZ (1.0-5.0 mg/l). Highest shoot induction response (42.40 %) was occurred at 4.0 mg/l TDZ from 72 hrs cold treated in vitro leaf. Highest number of shoots per explant (25.80) was observed at 3.0 mg/l TDZ from 48 hrs cold treated in vitro leaf explants. Highest shoot length (1.36 cm) was observed at 3.0 mg/l TDZ from 72 hrs cold treated in vitro leaf. Cold treatment was used first time in Stevia which improve the direct organogenesis from in vitro leaf explants.