title: Insect pollination reduces yield loss following heat stress in faba bean (Vicia fabaL.).
abstract: Global food security, particularly crop fertilization and yield production, is threatened by heat waves that are projected to increase in frequency and magnitude with climate change. Effects of heat stress on the fertilization of insect-pollinated plants are not well understood, but experiments conducted primarily in self-pollinated crops, such as wheat, show that transfer of fertile pollen may recover yield following stress. We hypothesized that in the partially pollinator-dependent crop, faba bean (Vicia fabaL.), insect pollination would elicit similar yield recovery following heat stress. We exposed potted faba bean plants to heat stress for 5 days during floral development and anthesis. Temperature treatments were representative of heat waves projected in the UK for the period 2021-2050 and onwards. Following temperature treatments, plants were distributed in flight cages and either pollinated by domesticatedBombus terrestriscolonies or received no insect pollination. Yield loss due to heat stress at 30 °C was greater in plants excluded from pollinators (15%) compared to those with bumblebee pollination (2.5%). Thus, the pollinator dependency of faba bean yield was 16% at control temperatures (18-26 °C) and extreme stress (34 °C), but was 53% following intermediate heat stress at 30 °C. These findings provide the first evidence that the pollinator dependency of crops can be modified by heat stress, and suggest that insect pollination may become more important in crop production as the probability of heat waves increases.
authors.affiliation: Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire RG6 6AR, UK.
authors.forename: Jacob
authors.initials: J
authors.lastname: Bishop
authors.affiliation: Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire RG6 6AR, UK.
authors.forename: Hannah Elizabeth
authors.initials: HE
authors.lastname: Jones
authors.affiliation: Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire RG6 6AR, UK; Czech University of Life Sciences in Prague, Kamýcká 129, 165 21 Praha 6 - Suchdol, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Lukac
authors.affiliation: Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire RG6 6AR, UK.
authors.forename: Simon Geoffrey
authors.initials: SG
authors.lastname: Potts
keywords: Climate change; Faba bean; Heat stress; Pollination; Yield stability; Yield variability