Plant regeneration from Eucalyptus bosistoana callus culture

Abstract

Eucalyptus bosistoana is an important durable hardwood species selected by New Zealand Dryland Forest Initiative (NZDFI) for their adaptability to diverse environments and good quality wood. There is no report on in vitro methods for callus induction and plantlet micropropagation of this species, although these methods could assist further genetic improvement of plants. In this study, different combinations of α-naphthalene acetic acid (NAA) and benzyl adenine (BA) at concentrations ranging from 0.5 to 2 mg L⁻¹ were investigated for callus induction, shoot regeneration, shoot elongation and root formation. High frequency of callus induction was obtained when cotyledon explants were cultured on MS (Murashige and Skoog medium 1962) with 1.0 mg L⁻¹ NAA and 1.5 mg L⁻¹ BA. For shoot regeneration from callus, MS medium with 0.5 mg L⁻¹ NAA and 1.5 mg L⁻¹ BA was an effective medium. Shoot elongation was observed on MS medium supplemented with 0.5 mg L⁻¹ NAA, 1.0 mg L⁻¹ BA and 1.0 mg L⁻¹ GA₃. High frequency of adventitious root formation in micro-cuttings of E. bosistoana was observed on half-strength MS medium with 0.5 to 1.0 mg L⁻¹ NAA. Finally, pre-acclimatization of the micropropagated plantlets led to 100% survival under glasshouse conditions.