Abstract Detail

Phylogenomics

Mandel, Jennifer [1], Siniscalchi, Carolina [2], Thapa, Ramhari [3], Dikow, Rebecca [4], Watson, Linda E [5], Funk, Vicki [6].

Evolution and Historical Biogeography of Asteraceae using Hyb-Seq Data.

Asteraceae (Compositae) comprise more than 25,000 species of sunflowers, artichokes, dandelions and daisies, and represent 10% of all flowering plant species on Earth. Prior to the use of phylogenomics for reconstructing phylogenies for the family, many evolutionary relationships were not well-resolved which has hindered advances in our understanding of the family's origin and historical biogeography. Using probes developed for the Hyb-Seq method, we sequenced approximately 1000 low-copy number nuclear markers plus partial plastomes for 250 species representing all major lineages within the family, which represents the most comprehensively-sampled Compositae phylogeny thus far. Using these data, we generated robust phylogenetic trees using both concatenated and coalescence-based analyses that represent nearly all subfamilies and tribes. In general, the topologies within tribes remain stable in both the nuclear and plastid trees, however relationships among subfamilies differ from existing classifications. Specifically, our nuclear data do not support the monophyly of Subfamilies Carduoideae and Cichorioideae, however phylogenies generated from plastid data provide weak support for their monophyly. The discordance between the nuclear and plastid phylogenies suggests that reticulation may have occurred in the history of these lineages. We are using fossil data as time calibration points to estimate the age of the family and the origins of its major lineages. While it has traditionally been assumed that the family diverged from its South American sister family, Calyceraceae, 50-40 MYA, more recent molecular phylogenetic dating studies have estimated the age of the family to be as old as 85-72 MYA by using a calibration point based on Compositae fossil pollen found in Antarctica. Another study explicitly excluded that fossil due to uncertainty in its identification, and estimated the family’s age to 69 MYA. These estimates were either based solely upon plastid phylogenies or nuclear loci with limited taxon sampling, we thus provide results from a comprehensive nuclear phylogeny both including and excluding the Antarctic fossil pollen. Our new phylogenetic reconstruction will provide unprecedented insight into the evolution and historical biogeography of the family including bolstering our understanding into the biogeographic origins, migrations, and diversifications of major lineages within Asteraceae.

Related Links:
Mandel Lab

1 - University of Memphis, 3700 Walker Avenue, Memphis, TN, 38152, United States
2 - University Of Memphis, Biological Sciences, 3700 Walker Ave, 239 Ellington Hall, Memphis, TN, 38152, United States
3 - The University of Memphis, Department of Biological Sciences, 3700 Walker Avenue , Memphis, TN, 38152, USA
4 - Smithsonian Institute, Washington DC
5 - Oklahoma State University, Plant Biology, Ecology, & Evolution, 301 Physical Sciences, Stillwater, OK, 74078, United States
6 - DEPT OF BOTANY-NHB 166, P.O. Box 37012, Washington, DC, 20013, United States

Keywords:
Compositae
Phylogenomics
Biogeography
Hyb-Seq
Sunflower.

Presentation Type: Oral Paper
Session: 11, Phylogenomics II
Location: 114/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 4:45 PM
Number: 11011
Abstract ID:738
Candidate for Awards:None