CONICET | Buscador de Institutos y Recursos Humanos

Most studies on pollinator-mediated selection have been performed in generalized rather than specialized pollination systems. This situation has impeded evaluation of the extent to which selection acts on attraction or specialized key .oral traits involved in the plant-pollinator phenotypic interphase. We studied pollinator-mediated selection in four populations of Nierembergia linariifolia, a self-incompatible and oil-secreting plant pollinated exclusively by oil-collecting bees. We evaluated whether .oral traits experience variable selection among populations and whether attraction and .t traits are heterogeneously selected across populations. Populations differed in every .ower trait and selection was consistently observed for corolla size and .ower shape, two traits involved in the .rst steps of the pollination process. However, we found no selection acting on mechanical-.t traits. The observation that selection occurred upon attraction rather than mechanical-.t traits, suggests that plants are not currently evolving .ne-tuned morphological adaptations to local pollinators and that phenotypic matching is not necessarily an expected outcome in this specialized pollination system.