Format: ORAL

Nikisha Patel1,2, Matt Johnson3, Rafael Medina4, Bernard Goffinet2

1. Biology Department, Trinity College, Hartford, Connecticut, USA 2. Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA 3. Department of Biology, Texas Tech University, Lubbock, Texas, USA 4. Departamento de Biodiversidad, Ecología y Evolución, Universidad Complutense, Madrid, Espana

Whole genome duplication (WGD) is a mechanism critical to evolutionary change and speciation across the plant tree of life. Both conspecific genome doubling (autopolyploidy) and WGD following hybridization (allopolyploidy) may result in morphologically distinct lineages and hence may contribute significantly to species diversity. However, accurate phylogenetic reconstruction of allopolyploids and their component genomes remains a major challenge. The moss Physcomitrium pyriforme is a widespread species complex found across North America and Europe that exhibits substantial morphological variation, evident in the recognition of 29 synonyms. We hypothesize that this species complex comprises not only numerous cytotypes and potential species from repeated WGD events, but also population structure among haploid populations that will inform the evolutionary history of allopolyploids and autopolyploids. We sampled over 400 populations of P. pyriforme across its North American and use a target capture approach to sequence 648 genes to construct a phylogenetic tree establishing relationships among P. pyriforme populations. 60 allopolyploid populations are identified using HybPhaser suggesting that WGD plays a substantial role in the evolution of the P. pyriforme complex. Further, structure analysis of haploid populations of P. pyriforme offers insights into gene flow and introgression further elucidating the nature of reticulation among haploid, autopolyploid, and allopolyploid populations. These analyses both provide evidence for morphologically cryptic speciation via polyploidy and also provides evidence for the utility of target capture sequencing with an 806 gene bait set for population genomic studies and population demographic inferences.