In vitro clonal propagation of mature Eucalyptus F1 hybrid (E. torelliana F. V. Muell x E. citriodora Hook)

Multiple shoots from mature nodal segments of 8-yr-old Eucalyptus F1 hybrid (E. torelliana x E. citriodora ) were obtained through tissue culture on Murashige and Skoog's medium supplemented with BAP, NAA and/or GA sub(3). Rooting of these shoots was obtained in one-half and one-fifth MS media each supplemented with 0.1 and 1.0 mg/l IBA, but the shoots were healthier in the latter medium. The rooted shoots (plantlets) were transferred to the field. Forty subcultures have already been carried out without any reduction in the capacity for shoot or root formation. It can be estimated that about 2,00000 plantlets can be obtained from a nodal segment in a year by this process. The method helps in retaining the vigour of F1 hybrid of Eucalyptus) which declines in successive generations through seed.