Bud regeneration from Eucalyptus globulus clones and seedlings through hormonal imbalances induced by Agrobacterium tumefaciens strain 82.139.

摘要

Bud regeneration from seedling hypocotyls and stem cuttings arising from micropropagated plantlets of Eucalyptus globulus was achieved using inoculation with Agrobacterium tumefaciens strain 82.139 which induced shooty tumours. The adventitious budsregenerated on the shooty tumours were untransformed as revealed by the use of a C58pMP90/T139GUS-INT strain harbouring the intron inactivated uidA (gus) reporter gene. Subsequent rooting and acclimatization were achieved for some of the regenerants. Flow cytometric analyses of nuclear DNA contents indicated that both the tumours and the regenerants were diploid. Endogenous hormone quantification was performed in shooty and non-shooty tumours induced by strains 82.139 and C58, respectively. The shootypotential of the strain 82.139 was associated with high Z and ZR levels in the tumours while auxin levels were similar in shooty and non-shooty tumours. The efficiency of the method could be useful for both regeneration and genetic transformation from organs of cloned E. globulus.