Phylogeography of Eucalyptus deglupta

Project summary

Eucalyptus deglupta is one of the four species of Eucalyptus that are not endemic to Australia. Eucalyptus deglupta has a distribution that extends from Papua New Guinea, through the islands of Indonesia, to the southern Philippines. The other three extra-Australian species are E. urophyllaE. orophila and E. wetarensis, which occur in Timor and adjacent islands. One of the common names of E. deglupta is 'Rainbow Gum', due to the beautiful colours of young bark on the trunk.

Eucalyptus deglupta is a variable fast growing species that is widely used in forestry for pulp, paper and timber, especially in tropical regions. Different provenances of E. deglupta vary in morphology, growth and pest resistance, but there has been no systematic study of those differences and there are no molecular data available at the population level.

The position of Eucalyptus deglupta in the eucalypt phylogeny is also uncertain, with it being placed by Ian Brooker in subgenus Minutifructus with three Australian species, E. brachyandraE. raveretiana and E. howittiana. However, molecular studies suggest these species may lie within the large subgenusSymphyomyrtus. Molecular phylogenetic markers from our population samples will be used to address this knowledge gap.

Eucalyptus deglupta is endangered in parts of its natural range due to loss of habitat and logging for timber and firewood. A better understanding of its population structure will help in managing its conservation, provide a basis for future research into inter-provenance variation, and may lead to improved understanding of the species for commercial applications.

Our collaborators in Indonesia have undertaken fieldwork in Seram, Sulawesi and Papua to collect samples for voucher specimens and DNA analysis. Microsatellite markers and DNA sequences are being used to conduct phylogenetic and population analyses.

Project team

  • Frank Udovicic (Royal Botanic Gardens Melbourne)
  • Michael Bayly (School of Botany, The University of Melbourne)
  • Gillian Dean (Bogor Botanic Garden, Indonesia)
  • Siti Roosita Ariati (Bogor Botanic Garden, Indonesia)
  • Campbell Webb (Arnold Arboretum of Harvard University, USA)

Support

  • The Australia and Pacific Science Foundation
  • Royal Botanic Gardens Melbourne
  • School of Botany, The University of Melbourne