title: To be or not to be better pollinated: Differences between sex morphs in marginal gynodioecious populations.
abstract: OBJECTIVE
  Changes in the pollinator communities of marginal plant populations can affect their pollination quantity or quality. Geographic variation in pollination success can alter the reproductive advantage that female plants require to persist within gynodioecious populations. Particularly valuable is determining the pollination success at the prezygotic stage in self-compatible gynodioecious species whose females do not exhibit enhanced seed production.
  
  
  METHODS
  In core and marginal populations of Daphne laureola, we analyzed the differences between hermaphrodites and females in the proportion of flowers visited, the stigma pollen loads, and the quantity of pollen tubes in styles. We also examined the relationship between the number of pollen tubes in styles vs. the number of pollen grains on stigmas using piecewise regression and binomial generalized linear mixed models.
  
  
  RESULTS
  Pollinators deposited larger pollen loads on flowers in marginal populations. In marginal populations, female flowers received more pollinator visits and more pollen grains on their stigmas, and they had more pollen tubes in their styles than did female flowers in core populations. Both piecewise regression and binomial GLMM analyses showed that females in marginal populations had a lower proportion of grains that developed tubes than females in the core populations, which suggests decreased pollination quality.
  
  
  CONCLUSIONS
  More efficient pollination services in marginal populations decreased the overall differences in the prezygotic pollination success between the sex morphs. Our results also suggest that pollination quality is lower in females of marginal populations, which could be counteracting the increased pollination in females in marginal populations.
authors.affiliation: Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio s/n 41092 Sevilla, Spain acastilla@utexas.edu.
authors.forename: Antonio R
authors.initials: AR
authors.lastname: Castilla
authors.affiliation: Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio s/n 41092 Sevilla, Spain.
authors.forename: Conchita
authors.initials: C
authors.lastname: Alonso
authors.affiliation: Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio s/n 41092 Sevilla, Spain.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Herrera
mesh_terms: D032364:Daphne / Q000502:physiology*; D035264:Flowers / Q000502:physiology*; D053205:Pollen Tube / Q000502:physiology; D054817:Pollination / Q000502:physiology*; D012044:Regression Analysis; D015053:Zygote / Q000502:physiology
keywords: Daphne laureola; Thymelaeaceae; gynodioecy; margins of distribution; piecewise regression; pollen grains; pollen tubes; pollinator fauna