Format: ORAL

Felipe Torres-Vanegas, Vanda Temesvri, Magne Friberg, ystein H. Opedal

Department of Biology, Biodiversity Unit, Lund University. Lund, Sweden. SE 223 62.

Pollinators are a fundamental driver of the diversification of floral traits. Indeed, the astonishing diversity of floral traits represent, in part, an adaptation to the behavioural preferences and functional characteristics of the associated pollinators. The composition of the local pollinator assemblage is expected to differ across the distribution range of a particular plant species, with the potential to generate a geographic mosaic of divergent patterns of phenotypic selection that can represent an avenue of adaptation to the local pollinator assemblage. Thus, studies that relate geographical variation in floral traits to the distinct regimes of phenotypic selection exerted by the local pollinator assemblage are fundamental to understand the interplay between microevolution and macroevolution. This is particularly relevant for generalized plant-pollinator interactions, where a particular plant interacts with a broad range of pollinators. Here, we evaluated whether geographical variation in the composition of the local pollinator assemblage can establish distinct regimes of phenotypic selection andunderlie the patterns of divergence in floral traits of Viscaria vulgaris. We observed a taxonomically and functionally broad range of diurnal and nocturnal pollinators that primarily included bumblebees, honeybees, solitary bees, syrphid flies, butterflies, and moths. We detected geographical variation in the composition of the local pollinator assemblage and the strength and direction of phenotypic selection on particular floral traits. Despite generalized plant-pollinator interactions, we detected that the observed variation in floral traits was associated with divergence in the composition of the local pollinator assemblage. We argue that generalized plant-pollinator interactions can exert phenotypic selection on floral traits and that distinct local pollinator assemblages can underlie the patterns of divergence in floral traits. Together, these outcomes indicate that specialized plant-pollinator interactions are not required to generate and maintain the diversity of particular floral traits.