Abstract Detail

Exploring the utility and limits of target enrichment methods to study polyploidy and reticulate evolution

Thomas, Shawn [1], Liu, Xiang [2], Cummings, Amanda [3], Pokorny, Lisa [4], Xiang, Jenny [5], Leebens-Mack, Jim [6].

Testing hypothesized reticulate evolution in the Cornales using targeted enrichment data.

The Cornales is an order of flowering plants containing ecologically and horticulturally important families of plants including Cornaceae (dogwoods) and Hydrangeaceae (hydrangeas), among others. The majority of the Cornales is found to be monophyletic, however the placement of the family Hydrostachyaceae remains uncertain as it is place both ingroup and outgroup to the Cornales in various studies. Previously, relationships among families in the Cornales have been estimated based on plastid genome or a few genes (26S rDNA, matK, ndhF, rbcL, and atpB). Here we tested these phylogenetic inferences using hundreds of loci with the Angiosperm353 set in a coalescence-based analysis. Analyses of more than 100 samples, representing all families and with more intensive sampling in the Cornaceae, have produced a species tree that preserves the monophyly of Cornales. The relationships among families are largely congruent with previous studies except for the placement of the nyssoids-mastixioids clade. We see high support values and a high degree of concordance among individual nuclear gene trees across most of the inferred species tree. However, precise placement of the family Hydrostachyaceae was not confidently resolved. Gene tree discordance implicates a rapid radiation and incomplete lineage sorting. Interspecific gene flow early in the history of the Hydrostachyaceae lineage is also a possibility. Within the family Cornaceae, we see strong support for the monophyly of each morphogroup, but patterns of tree discordance, among these groups, suggest ancient reticulation may have contributed to early diversification of Cornus. We explore hypothesized reticulate evolution in the Cornales more deeply through formal tests for ancestral reticulations. Our findings elucidate the diversification process across the Cornales and demonstrate the utility of the Angiosperm353 bait set.

1 - University Of Missouri, Division Of Biological Sciences, 1201 Rollins Street, 311 Bond Life Sciences Center, Columbia, MO, 65211, United States
2 - North Carolina State University, Department of Plant and Microbial Biology, Raleigh, NC, 27695, USA
3 - University of Georgia, Department of Plant Biology, Athens, GA, 30602, USA
4 - Centre For Plant Biotechnology And Genomics UPM-INIA, Computational/Systems Biology And Genomics Program, Autopista M-40, Km 38, Pozuelo De Alarcón, 28223, Spain
5 - North Carolina State University, Plant And Microbial Biology, Campus Box 7612, Gardner Hall 2115, Raleigh, NC, 27695, United States
6 - University Of Georgia, Plant Biology, 2101 Miller Plant Sciences, Athens, GA, 30602, United States

Keywords:
phylogenomics
Target Enrichment
reticulate evolution
Angiosperm353.

Presentation Type: Colloquium Presentations
Session: COL04, Exploring the utility and limits of target enrichment methods to study polyploidy and reticulate evolution
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 11:45 AM
Number: COL04008
Abstract ID:612
Candidate for Awards:Margaret Menzel Award