Studies on Eucalyptus regeneration systems

Four protocols for Eucalyptus regeneration were obtained,including(i)micropropagation in vitro culture through axillary budding:using axillary bud from branch cutting as explant and the hormone combination of 1.0 mg/ L 6-BA and 0.5 mg/ L NAA,and the amount of regeneration shoots were obtained by axillary budding and multiplication.(ii)shoot organogenesis from callus:using hypocotyl and cotyledon as materials,modified MS medium containing 1.0 mg/ L 6-BA combined with 1.5 mg/ L NAA was used to induce callus and combinations of TDZ (0.1-0.5 mg/ L)or 6-BA(1.0-2.0 mg/ L)and NAA(0.2-0.5 mg/ L)was used for shoots differentiation.(iii)somatic embryogenesis:calli were obtained with the same method as above,and transferred to the combination of TDZ 1.0 mg/L and Casein 1 g/L for embryos formation and shoots regeneration.(Ⅳ)direct shoot formation from leaf:using young leaves from seedling or in vitro culture as explants,cultured with the combination of 1.0 mg/ L TDZ and 0.5 mg/ L NAA,adventitious buds occurred directly from leaf.In addition, the results also showed that explants source and hormone concentration significantly affected shoots regeneration in the same way.