Phylogeography of Eucalyptus deglupta

A collaborative project undertaken by Royal Botanic Gardens Melbourne, The University of Melbourne, and Bogor Botanic Garden, Indonesia, and supervised by Frank Udovicic (Royal Botanic Gardens Melbourne)

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.   One of its common names is ‘Rainbow Gum’, due to the beautiful colours of young bark on the trunk.  It 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 is no molecular data available at the population level.  

The position of E. deglupta in the eucalypt phylogeny is also uncertain, with it being placed by eucalypt authority, Ian Brooker, in subgenus Minutifructus with 3 Australian species, E. brachyandra, E. raveretiana and E. howittiana; however, molecular studies suggest these species may lie within the large subgenus Symphyomyrtus.  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.  

The Indonesia-based members of our team undertook a field trip in Seram and Sulawesi to collect samples for voucher specimens and DNA analysis.   DNA sequence markers will be used to conduct the phylogenetic and population analyses. Population level data may be supplemented with microsatellite markers if necessary. 

Figure Legends

Figure 1. Colourful trunk of Eucalyptus deglupta (Rainbow Gum), Mual River, Seram Island, Maluku, Indonesia

Figure 2. Buds and fruits of Eucalyptus deglupta, Isal River, Manusela National Park, Seram Island, Maluku, Indonesia

Figure 3. Gillian Dean (second from left) and Sita Ariati (third from left) with field assistants processing samples of Eucalyptus deglupta Isal River, Manusela National Park, Seram Island, Maluku, Indonesia

Figure 4. Habitat of Eucalyptus deglupta, Isal River, Manusela National Park, Seram Island, Maluku, Indonesia

Figure 5. Field assistant climbing neighbouring rough-barked tree to sample from canopy of smooth-barked Eucalyptus deglupta Enrekang, South Sulawesi, Indonesia

 

 

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