Format: ORAL

Daniel J. Murphy1, Bruce Maslin2, Theodore Allnutt1, Todd McLay3

1 Royal Botanic Gardens Victoria, Melbourne, Victoria 3004, Australia 2 Western Australian Herbarium, Kensington, Western Australia 6152, Australia 3 National Biodiversity DNA Library, National Collections and Marine Infrastructure, CSIRO, Parkville, 3052

Acacia Australias largest genus of flowering plants was selected for a Genomics for Australian Plants (GAP)-supported phylogenomic analysis using the Angiosperms353 target capture bait set. While Sanger amplicon sequencing datasets have previously been compiled for approximately 50% of Acacia species, those datasets comprised fewer than 10 markers and lacked phylogenetic resolution in certain parts of the tree, demonstrating the need for a deeper phylogenomic-based sampling of the Acacia genome in order to resolve the phylogeny with greater support. In this talk, results are presented of an initial phylogenomic analysis of around 10% of the total number of Australian Acacia species, sequenced for the Angiosperms353 target capture baits and representing all major evolutionary lineages of Acacia that had previously been discovered in molecular phylogenies and morphological classifications. Initial phylogenetic analyses, including appropriate mimosoid legume outgroups and using several analytical approaches, have revealed congruence in the major clades that were previously discovered, such as the Pulchelloidea clade, which unites morphologically disparate taxa from several traditional sections in Acacia. When compared to the topologies found in previous molecular phylogenetic studies, the overall phylogenomics-based topology is somewhat different, which may be due to increased phylogenetic resolution of the markers or differences in the targeted sampling of species in particular parts of the tree. Some novel clades, including a sister clade to the majority of Acacia species, are recovered in our analyses. Due to the level of support for relationships, in combination with the very high success rates for sequencing of silica-dried and older herbarium samples, the Angiosperms353 bait set shows great potential as the basis for a larger-scale study of Acacia species, with the ultimate aim of generating a new formal classification of the genus.