Abstract Detail

Biogeography

Fahey, Patrick [1], Fowler, Rachael [1], Cantrill, David [2], Udovicic, Frank [3], Bayly, Michael [1].

The phylogeography of Eucalyptus behriana (Bull mallee): a story of many signals.

The eucalypts, comprising over 750 species across three genera: Angophora, Corymbia and Eucalyptus, are a highly diverse group of trees and shrubs that dominate wooded communities right across the Australian continent. As such a lot of effort has been put into understanding their evolution and diversity, however there is much we still do not know, especially regarding their biogeographical history and what this can tell us about historical environmental changes in Australia. I will be presenting the results of a phylogeographical study of Eucalyptus behriana (Bull Mallee, Broad-leaved box) using both chloroplast genomes and anonymous nuclear genome loci. This species is a mallee, a shrub with multiple trunks arising from a lignotuber, which occurs as scattered populations in semi-arid south-east Australia, some of which are isolated by hundreds of kilometres. There is no significant morphological differentiation between populations, suggesting events giving rise to the scattered distribution were recent in evolutionary terms, a pattern that has been observed in several plant taxa that occur in or around the lower Murray River Basin, part of the larger Murray-Darling Basin which occupies much of the south-east inland. For this reason, we identified E. behriana as a potentially enlightening case study to increase our understanding of how historic environmental changes may have given rise to shared biogeography patterns in the region. Our study is the first on E. behriana to use molecular data, and by utilising sequence data from the plastid and the nuclear genome, we highlight the misleading conclusions that can be drawn when plastids are used in isolation. We resolve many relationships between populations and show that the Murray Basin is indeed the most significant disjunction in the species distribution.

1 - School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
2 - Royal Botanic Gardens Victoria, Private Bag 2000, Birdwood Avenue, South Yarra, VIC, 3141, Australia
3 - Royal Botanic Gardens Victoria, Private Bag 2000, Birdwood Avenue, South Yarra, Victoria, 3141, Australia

Keywords:
Eucalyptus
phylogeography
Hybridisation
Vicariance
genome skimming
ddRAD-seq.

Presentation Type: Oral Paper
Session: BIOG1, Biogeography I
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 10:30 AM
Number: BIOG1003
Abstract ID:313
Candidate for Awards:None