Stephens, Jessica , Rogers, Willie , Mason, Chase , Donovan, Lisa , Malmberg, Russell .
Species tree estimation of the genus Helianthus (Asteraceae) using target enrichment.
The sunflower genus Helianthus has long been recognized as economically significant, containing species of agricultural and horticultural importance. Additionally, this genus displays a large range of phenotypic and genetic variation, making Helianthus a great system for studying evolutionary and ecological processes. Here we present the most robust Helianthus phylogeny to date, laying the foundation for future studies regarding members of this genus. We used a target enrichment approach across 37 diploid Helianthus species/subspecies with a total of 103 accessions. This technique garnered 170 genes used for both coalescent and concatenation analyses. The resulting phylogeny was additionally used to examine the evolution of life history and growth form across the genus. Both coalescent and concatenation approaches were largely congruent, resolving a large annual clade and two large perennial clades. However, several relationships deeper within the phylogeny were more weakly supported and incongruent among analyses, including the placement of H. agrestis, H. cusickii, H. gracilentus, H. mollis, and H. occidentalis. The current phylogeny supports three major monophyletic clades, including a large annual clade, a southeastern perennials clade, and another large perennial clade. Relationships among taxa are more consistent with early phylogenies of the genus using morphological and crossing data than more recent efforts using single genes, highlighting the difficulties of phylogenetic estimation in genera known for reticulate evolution. Additionally, conflict and low support at deeper nodes among the perennials may suggest a quick radiation and/or ancient introgression within the genus.
1 - University Of Georgia, Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, USA
2 - University of Georgia, Plant Biology
Presentation Type: Oral Paper:Papers for Topics
Candidate for Awards:Margaret Menzel Award