Abstract Detail

Reproductive Processes

Depatie, Trinity [1], Wessinger, Carolyn [2].

The evolutionary history and potential function of personate flowers in eastern Penstemons.

The genus of North American wildflowers, Penstemon, shows remarkable variation in floral traits making it a useful system for studying processes of diversification. A few species of Penstemon display a distinct personate shape. Personate flowers are characterized by an upward bulge in the lower lip of the corolla tube that ultimately seals off the floral passageway. Personate flowers have evolved at least two times within Penstemon (sect. Penstemon and sect. Dasanthera) and exist in other species in the family Plantaginaceae (e.g., Antirrhinum and Linaria). Despite the repeated evolution of this floral trait, little is known about its ecological function or genetic basis. Potential ecological functions include a role in facilitating pollinator specialization and/or a role in mediating self-pollination. We conducted a phylogenomic analysis of eastern North American Penstemon species to examine evolutionary relationships among species. This analysis suggests that personate flowers have evolved a single time within this group, leading to a clade of species that display fully or nearly personate flowers. We are currently generating whole-genome resequencing data in order to clarify topological discordance. We have conducted preliminary observations of pollinator visitation in populations of personate and open-tubed Penstemons and have found the following pattern: only large bees visit personate flowers while bees of various sizes visit open-tubed flowers. Our preliminary mating system studies suggest that, overall, P. hirsutus produces more seeds per fruit than P. smallii (open-tubed flowers) and the personate morphology of P. hirsutus assists with self-fertilization. Future work will increase population sampling and the number of observed pollinators. Additionally, we are conducting a QTL analysis to understand the number of genetic changes required for the evolution of personate flowers from the ancestral open-tubed floral form.

1 - Trinity Depatie, 1321 Lady Street, Apt. 800, Columbia, SC, 29201, United States
2 - 1010 Henderson St, Columbia, SC, 29201, United States

personate flowers

Presentation Type: Oral Paper
Number: RP5003
Abstract ID:456
Candidate for Awards:None

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