title: Negative effects of heterospecific pollen receipt vary with abiotic conditions: ecological and evolutionary implications.
abstract: OBJECTIVE
  Studies that have evaluated the effects of heterospecific pollen (HP) receipt on plant reproductive success have generally overlooked the variability of the natural abiotic environment in which plants grow. Variability in abiotic conditions, such as light and water availability, has the potential to affect pollen-stigma interactions (i.e. conspecific pollen germination and performance), which will probably influence the effects of HP receipt. Thus, a more complete understanding of the extent, strength and consequences of plant-plant interactions via HP transfer requires better consideration of the range of abiotic conditions in which these interactions occur. This study addresses this issue by evaluating the effects of two HP donors (Tamonea curassavica and Angelonia angustifolia) on the reproductive success of Cuphea gaumeri, an endemic species of the Yucatan Peninsula.
  
  
  METHODS
  Mixed (conspecific pollen and HP) and pure (conspecific pollen only) hand-pollinations were conducted under varying conditions of water and light availability in a full factorial design. Reproductive success was measured as the number of pollen tubes that reached the bottom of the style.
  
  
  RESULTS
  Only one of the two HP donors had a significant effect on C. gaumeri reproductive success, but this effect was dependent on water and light availability. Specifically, HP receipt caused a decrease in pollen tube growth, but only when the availability of water, light or both was low, and not when the availability of both resources was high.
  
  
  CONCLUSIONS
  The results show that the outcome of interspecific post-pollination interactions via HP transfer can be context-dependent and vary with abiotic conditions, thus suggesting that abiotic effects in natural populations may be under-estimated. Such context-dependency could lead to spatial and temporal mosaics in the ecological and evolutionary consequences of post-pollination interactions.
authors.affiliation: Department of Tropical Ecology, University of Yucatan, Km. 15·5 Merida-Xtmakuil, Yucatan, 97000, Mexico and.
authors.forename: Ileana N
authors.initials: IN
authors.lastname: Celaya
authors.affiliation: Department of Tropical Ecology, University of Yucatan, Km. 15·5 Merida-Xtmakuil, Yucatan, 97000, Mexico and gtarceo@hotmail.com.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Arceo-Gómez
authors.affiliation: Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Apdo. 1056, E-41092, Sevilla, Spain.
authors.forename: Conchita
authors.initials: C
authors.lastname: Alonso
authors.affiliation: Department of Tropical Ecology, University of Yucatan, Km. 15·5 Merida-Xtmakuil, Yucatan, 97000, Mexico and.
authors.forename: Víctor
authors.initials: V
authors.lastname: Parra-Tabla
mesh_terms: D004777:Environment; D008027:Light; D029561:Lythraceae / Q000502:physiology*; D008800:Mexico; D011058:Pollen / Q000502:physiology*; D053205:Pollen Tube / Q000254:growth & development*; D012098:Reproduction; D028083:Scrophulariaceae / Q000502:physiology*; D013045:Species Specificity; D029648:Verbenaceae / Q000502:physiology*; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water
keywords: Angelonia angustifolia; Co-flowering species; Cuphea gaumeri; Tamonea curassavica; Yucatan Peninsula; heterospecific pollen; pollen tube growth; pollination ecology; pollinator sharing; post-pollination interactions; reproductive success