Abstract Detail

Phylogenomics

McLay, Todd [1], Doyle, Stephen [2], Tibbits, Josquin [3], Bayly, Mike [1].

Resolving the evolutionary history of the Australian grass trees, Xanthorrhoea, using multiple next-generation seqeuncing techiques.

The Australian grass tree genus Xanthorrhoea (Xanthorrhoeaceae subfamily Xanthorrhoeoideae) is an iconic component of the Australian flora. It is found in eastern and south-western Australia in heathlands, woodlands and dry sclerophyll forests. The 28 species are instantly recognisable to genus, but relationships between species are difficult to determine. The currently described species have a similar morphology with few consistent characters for delimitation, and many species overlap in their geographical distributions. As well as being morphologically similar, early searches for genetic variation using chloroplast intron sequences identified very little divergence between species and produced phylogenies suggestive of hybridisation or lineage sorting.
The potential of next-generation sequencing to produce millions of sequences is promising for studying evolutionary questions in difficult to resolve groups, but application of the technology is still in its infancy, and sequencing costs can be prohibitive. Here I will present the results from several different library preparation methods for Illumina sequencing in order to identify genetic variation in Xanthorrhoea. Firstly, a targeted amplicon sequencing approach was used to resolve the phylogeny of Xanthorrhoea, using GenBank data as a resource to identify potential amplicons. Secondly, double digest RAD sequencing was used to obtain population level genetic information for delimitation of Western Australian taxa. Finally, I developed a PCR based reduced representation library preparation method to study hybridisation and the impact of disease on genetic variation in populations of Xanthorrhoea. These different methods display the utility of next-generation sequencing in obtaining large amounts of sequence variation, at an affordable cost per sample, for testing hypotheses in a group with low molecular variation. Todd McLay, Stephen Doyle, Josquin Tibbits, Mike Bayly

1 - University of Melbourne, School of Biosciences, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia
2 - La Trobe University, School of Molecular Sciences, RL Reid Building, La Trobe University, Bundoora, Melbourne, VIC, Australia
3 - University of Melbourne, Department of Forest and Ecosystem Science, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia

Keywords:
RADseq
amplicon
marker development
Species delimitation.

Presentation Type: Oral Paper:Papers for Topics
Session: 73
Location: Salon 9/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 2:00 PM
Number: 73003
Abstract ID:983
Candidate for Awards:Margaret Menzel Award