|MORRIS, GEOFFREY - Kansas State University|
|BOREVITZ, JUSTIN - Canberra|
Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2014
Publication Date: 1/10/2015
Citation: Grabowski, P.P., Morris, G., Casler, M.D., Borevitz, J. 2015. Population genomic variation reveals roles of history, adaptation, and ploidy in switchgrass [abstract]. Plant and Animal Genome Conference. Paper No. 0023.
Technical Abstract: Diversity within a species is shaped by many processes, including mutation, migration, and natural selection. These processes leave signatures in geographic and genomic patterns of variation, and characterizing the patterns provides insight into the roles of different factors in shaping diversity. We used genotyping-by-sequencing to measure variation in switchgrass (Panicum virgatum, L.), a wide-ranging perennial grass, from across its range in the United States. Patterns of population structure reflect biogeographic and ploidy differences within and between switchgrass ecotypes and indicate that biogeographic history, ploidy incompatibilities, and differential adaptation have helped shape ecotypic differentiation in switchgrass. These patterns indicate that the differentiation between tetraploid and octoploid lineages is not caused exclusively by ploidy differences. For example, patterns of diversity in octoploid lineages is consistent with a history of admixture, suggesting that polyploidy in switchgrass is promoted by admixture of diverged lineages. These results provide new insights into the mechanisms shaping variation in widespread species and demonstrate the capacity for sequencing-based genotyping methods to address questions in genetically complex systems.