title: Small reductions in corolla size and pollen: ovule ratio, but no changes in flower shape in selfing populations of the North American Arabidopsis lyrata.
abstract: The shift from outcrossing to selfing is often accompanied by striking changes in floral morphology towards a "selfing syndrome", which is characterized by flowers with reduction in size, pollen: ovule (P/O) ratio, and herkogamy. This study aims to test whether such changes have occurred in the North American Arabidopsis lyrata, which is of particular interest because of the relatively recent transitions to selfing in this system. Flower size, flower shape, herkogamy levels, P/O ratio, and floral integration of six self-incompatible (outcrossing) and six self-compatible (selfing) populations of A. lyrata were measured in a common environment using conventional and geometric morphometrics methods. Although selfers had on average 9.2% smaller corollas, 8.4% longer pistils, and 21.5% lower P/O ratios than outcrossers, there were no differences in shape, floral integration, and herkogamy between outcrossing and selfing populations. Moreover, most variation in floral traits was explained by population genetic background rather than by mating system. We conclude that selfing populations in A. lyrata have not evolved a selfing syndrome.
authors.affiliation: Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany. samuel.carleial@gmail.com.
authors.forename: Samuel
authors.identifier: 0000-0001-6725-1945
authors.initials: S
authors.lastname: Carleial
authors.affiliation: Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: van Kleunen
authors.affiliation: Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Stift
mesh_terms: D017360:Arabidopsis; D035264:Flowers / Q000033:anatomy & histology; D056771:Ovule; D011058:Pollen; D012098:Reproduction
keywords: Breeding system; Evolution; Geometric morphometrics; Self-compatibility; Selfing syndrome