Abstract Detail

Phylogenomics

Mason-Gamer, Roberta J. [1], White, Dawson [1].

Relationships within the wheat tribe Triticeae (Poaceae): phylogenetic trees based on chloroplast genomes and 150 nuclear loci.

Phylogenetic relationships within the wheat tribe, Triticeae (Poaceae), have remained intractable in spite of numerous systematic analyses based on morphological, cytogenetic, and molecular phylogenetic data. Generating a single, well-supported phylogenetic tree has been confounded by a combination of (1) introgression and incomplete lineage sorting, leading to conflict among gene trees; (2) frequent polyploidization, leading to explicitly reticulate relationships; and (3) rapid diversification of early lineages, resulting in poor resolution among them. To clarify of the group's evolutionary history, we are applying a Hyb-Seq approach, which combines targeted enrichment of low-copy sequences with skimming of non-targeted, high-copy sequences. With this method, we have obtained sequence data from (1) presumably single-copy nuclear loci, including targeted exons and flanking, non-targeted introns; and (2) complete or nearly-complete chloroplast genomes skimmed from the bait-hybridization reaction. We currently include only diploid species, in order to avoid the complications introduced by known reticulate taxa. The data set comprises 75 individuals representing a broad diversity of the tribe, and two outgroups. We present (1) a highly-resolved and well-supported chloroplast DNA tree; (2) a tree based on 150 nuclear loci, estimated with both a concatenated analysis using maximum likelihood and a quartet-based method; and (3) a summary of the well-supported conflict and consensus between the trees.

1 - University of Illinois at Chicago, Biological Sciences, 845 W. Taylor St., MC 066, Chicago, IL, 60607, USA

Keywords:
Hyb-Seq
targeted sequence enrichment
phylogenomics
Gramineae.

Presentation Type: Oral Paper
Session: 33, Phylogenomics II
Location: Fort Worth Ballroom 4/Omni Hotel
Date: Wednesday, June 28th, 2017
Time: 8:45 AM
Number: 33004
Abstract ID:492
Candidate for Awards:None