Abstract Detail

Phylogenomics

McKain, Michael [1], McAllister, Chrissy [2], Biang, Kathrines [2], Clewel, Sarah [2], AuBuchon, Taylor [1], Saeidi, Saman [1], Welker, Cassiano [3], Art-han, Watchara [4], Pasquet, Remy [5], Traiperm, Paweena [4], Kellogg, Elizabeth Anne [1].

Phylogenomics and adaptive trait evolution of ecologically dominant grasses.

Grasslands, including savannahs, play a pivotal role in biogeochemical processes and fostering biodiversity. They account for upwards to 30% of global carbon sequestration, enriching valuable prairie-like soils and producing economically viable cellulosic materials for biofuel production. Many of the ecologically dominant taxa of these ecosystems are members of the grass tribe Andropogoneae, which includes crops like maize, sorghum, and sugarcane. Nested within the core Andropogoneae is a monophyletic group of 250 species we call the DASH clade, which includes the genera Diheteropogon, Andropogon, Schizachyrium, and Hyparrhenia. The clade represents the majority of both the species diversity and total biomass of tropical, semi-tropical, and North American grasslands. Included in this group are iconic species of the North American prairie: big bluestem, Andropogon gerardii, and little bluestem, Schizachyrium scoparium. We sought to 1) define the circumscription of genera of the DASH clade, 2) reconstruct species relationships within the clade, and 3) explore the role of diaspore morphology as a potential factor in the success of this clade. We find that many generic limits within the Andropogoneae need to be reconsidered, particularly for the widespread, ecologically dominant genus Andropogon. Polyploidy is rampant across the DASH genera and includes some examples of intergeneric allopolyploidy, like in the hexaploid species Andropogon gerardii. In addition to its namesake genera, the clade includes the previously unplaced Old World genera, Exotheca, Eylmandra, and Monocymbium. We explore the relationships of these genera and their constituent species. We find that some aspects of diaspore morphology correlate with the environment, hinting at possible drivers of diversification. We further investigate the link between environment and diaspore morphology in the context of evolutionary relationships.

1 - Donald Danforth Plant Science Center, Department Of Biology, 975 North Warson Road, St. Louis, MO, 63132, USA
2 - Principia College, 1 Front Gate Rd, Elsah, IL, 62028, United States
3 - Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Botânica, Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil
4 - Mahidol University, Department of Plant Science, Bangkok, Thailand
5 - ICIPE

Keywords:
none specified

Presentation Type: Oral Paper
Session: 16, Phylogenomics II
Location: 202/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 8:45 AM
Number: 16004
Abstract ID:572
Candidate for Awards:Margaret Menzel Award