Micropropagation of an Eucalyptus hybrid (Eucalyptus benthamii x Eucalyptus dunnii) - doi: 10.4025/actasciagron.v33i4.8317

Resumo

This study was designed to micropropagate E. benthamii x E. dunnii, by testing chlorine concentrations for explant asepsis, the optimal concentrations of benzylaminopurine (BAP) and naphthaleneacetic acid (NAA) for bud proliferation, and the ratio between BAP and gibberellic acid (GA₃) in two nutrient media for shoot elongation. Nodal segments from H12, H19 and H20 clones were disinfected with 0.5, 1.0, 1.5 and 2.0% (v v^-1) of chlorine. Explants were grown on ½MS medium supplemented with BAP (0, 0.25, 0.50, 0.75 and 1.00 mg L^-1) and NAA (0, 0.025, 0.050, 0.075 and 0.100 mg L^-1) for bud production. They were elongated on MS and ½MS media supplemented with BAP (0, 0.05 and 0.10 mg L^-1) and GA₃ (0, 0.1, 0.2 and 0.3 mg L^-1). The 0.50 mg L^-1 BAP and 0.050 mg L^-1 NAA combination was optimal for bud proliferation for H12 and H20. GA³ concentrations of 0.10 and 0.2^-1 mg L^-1 combined with 0.10 mg L^-1 BAP on ½MS resulted in the longest shoots, for H12 and H20, respectively. Regardless of clone, the rooting rate was low, with an average of 12.0% and 14.4% of plants having roots for in vitro and ex vitro conditions, respectively.