Plant Regeneration in Eucalyptus pellita

In this study, two different approaches of regeneration systems for explants in Eucalyptus pellita have been taken to establish an efficient differentiation and regeneration protocols. The somatic embryogenesis from in vitro hypocotyls and cotyledons in Eucalyptus pellita has been investigated.The typical three kinds of callus types were induced from hypocotyls and cotyledons cultured on the 2,4-D containing medium with BA or kinetin. High frequency (82%) plantlet production from the friable, granular embryogenic callus derived from hypocotyls has been obtained on the differentiation medium(1μ MTDZ; 1μ MBA plus 0.1μ MNAA)developed in this study. The relationship between the callus types formed on different callus induction media and their corresponding differentiation rate was further discussed.In addition, plant regeneration through organogenesis from in vitro hypocotyls, cotyledons and mature leaves in Eucalyptus pellita has also been conducted with the modified basal B5 medium supplemented with a range of combinations of BA and NAA.The highest frequency of shoot formations for three kinds of explants varied on the different regeneration medium, with the regeneration rate for leaves, cotyledons and hypocotyls in ascending order: 41.67%, 66.67% and 83.33%, respectively.The significance of the two different plant regeneration systems was discussed. To our knowledge, this is the first report on the regeneration of Eucalyptus pellita.