In vitro Propagation of Rhododendron griffithianum Wt.: An Endangered Rhododendron Species of Sikkim Himalaya

Abstract

A reproducible protocol for in vitro propagation of R. griffithianum has been established. Multiple shoot proliferation from shoot-tip explants was occurred in the presence of 2-isopentenyl adenine (2-iP) alone or in combination with indole 3-butyric acid (IBA) in Anderson's medium. The best treatment for shoot regeneration was Anderson's medium supplemented with 5 µM 2-iP and 1.0 µM IBA, which promoted shoot proliferation in more than 75% culture with an average of 11.00 shoots per explants after twelve weeks. These shoots were successfully rooted on Anderson's liquid medium supplemented with 1.5 µM IBA. The rooted plantlets were hardened in greenhouse with 84% survival rate.