title: Elevated temperature drives a shift from selfing to outcrossing in the insect-pollinated legume, faba bean (Vicia faba).
abstract: Climate change can threaten the reproductive success of plants, both directly, through physiological damage during increasingly extreme weather events, and indirectly, through disruption of plant-pollinator interactions. To explore how plant-pollinator interactions are modified by extreme weather, we exposed faba bean (Vicia faba) plants to elevated temperature for 5 d during flowering, simulating a heatwave. We then moved the plants to flight cages with either bumblebees or no pollinators, or to two field sites, where plants were enclosed in mesh bags or pollinated by wild insect communities. We used a morphological marker to quantify pollen movement between experimental plants. There was a substantial increase in the level of outcrossing by insect pollinators following heat stress. Proportion outcrossed seed increased from 17 % at control temperature, to 33 % following heat stress in the flight cages, and from 31 % to 80 % at one field site, but not at the other (33 % to 32 %). Abiotic stress can dramatically shift the relative contributions of cross- and self-pollination to reproduction in an insect pollinated plant. The resulting increases in gene flow have broad implications for genetic diversity and functioning of ecosystems, and may increase resilience by accelerating the selection of more stress-tolerant genotypes.
authors.affiliation: School of Agriculture, Policy, and Development, University of Reading,RG6 6AR, UK.
authors.forename: Jacob
authors.initials: J
authors.lastname: Bishop
authors.affiliation: School of Agriculture, Policy, and Development, University of Reading,RG6 6AR, UK.
authors.forename: Hannah E
authors.initials: HE
authors.lastname: Jones
authors.affiliation: School of Agriculture, Policy, and Development, University of Reading,RG6 6AR, UK.
authors.forename: Donal M
authors.initials: DM
authors.lastname: O'Sullivan
authors.affiliation: School of Agriculture, Policy, and Development, University of Reading,RG6 6AR, UK.
authors.forename: Simon G
authors.initials: SG
authors.lastname: Potts
mesh_terms: D000818:Animals; D057231:Climate Change; D018556:Crops, Agricultural / Q000502:physiology*; D006358:Hot Temperature; D007313:Insecta; D054817:Pollination / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D031307:Vicia faba / Q000502:physiology*
keywords: Allogamy; Vicia faba.; autogamy; climate change; extreme weather; heat stress; insect pollination; plant–climate interactions; plant–pollinator interactions