CALLUS INDUCTION AND PLANT REGENERATION OF STEVIA (Stevia rehaudiana B.)

Abstract

The present research work was carried out in Biotechnology laboratory of the Department of Biotechnology. Sher-e-Bangla Agricultural University. Shcr-e-Bangla Nagar, Dhaka- 1207 from the period of January 2014 to December 2014 to evaluate the effects of different plant growth regulators in in vitro on shoot proliferation and root lbrmation and finally to develop a viable micropropagation protocol in Stevia (Stevia rehaudiana) using shoot tip and nodal segments as explants. Explants was inoculated in MS (Murashige and Skoog) media supplemented with the Benzvladenine (BA) and Kinetine (KIN) for direct shoot formation. Combination of BA and Indolebutyricacid (IBA) as well as combination of KIN and IBA were used in MS medium for indirect shoot formation via callus induction. The highest percent of shoot induction (83.42%) obtained on 2.0 mg/L BA and the minimum days to shoot induction (10.6) were also obtained on 2.0 mg/I.. BA. The highest 10.8 shoots and 17.2 leaves per explants also observed in BA 2.Omg/L. But maximum average length of shoots per explants (3.94 cm) were reported from media containing 1mg/I. KIN. Highest callus induction potentiality (83.58%) was observed in 2 mg/L BA+1.5 mg/L IBA The minimum days to callus induction (13.4) were recorded in 1.0 mg/L KIN+I.5 mg/L IBA but the minimum days to shoot induction (9.6) from callus were recorded in 2.0 mg/L BA+1.5 mg/L IBA. Righest percent of root induction (78.18%) with 7.2 roots per explants and minimum 12.6 days to root induction were noticed on 1.0 mg/I. IBA. The combined ellèct on percent of' root induction was highest (76.92%) in the treatment of 1.0 mg/L KIN t 0.5 mg/L IBA. The same treatment showed minimum days (13.4) to root induction and maximum number of roots per explants. In acclimatization 90%, 80% and 80% survival rate were recorded in growth cabinet, shade house and field condition respectively. In vitro regeneration technique was found to be very effective and promising niethod in the proliferation of Stevia and this method can be used 11w large scale production of disease free and quality planting material.