Abstract
Microorganisms frequently colonize the nectar of angiosperm species. Though capable of altering a suite of traits important for pollinator attraction, few studies exist that test the degree to which they mediate pollinator foraging behavior. The objective of our study was to fill this gap by assessing the abundance and diversity of yeasts associated with the perennial larkspur Delphinium barbeyi (Ranunculaceae) and testing whether their presence affected components of pollinator foraging behavior. Yeasts frequently colonized D. barbeyi nectar, populating 54–77% of flowers examined depending on site. Though common, the yeast community was species-poor, represented by a single species, Metschnikowia reukaufii. Female-phase flowers of D. barbeyi were more likely to have higher densities of yeasts in comparison to male-phase flowers. Pollinators were likely vectors of yeasts, as virgin (unvisited) flowers rarely contained yeasts compared to flowers open to pollinator visitation, which were frequently colonized. Finally, pollinators responded positively to the presence of yeasts. Bombus foragers both visited and probed more flowers inoculated with yeasts in comparison to uninoculated controls. Taken together, our results suggest that variation in the occurrence and density of nectar-inhabiting yeasts have the potential to alter components of pollinator foraging behavior linked to pollen transfer and plant fitness.
Highlights
Even though the chemical composition of nectar could strongly select against microorganisms [9,10,11], recent studies suggest that microorganisms routinely colonize the nectar of many plant species [5], [8], [12]
The most common pollinators of D. barbeyi around Rocky Mountain Biological Laboratory (RMBL) are bumble bees but flowers are visited by hummingbirds (Selasphorus platycercus and S. rufus), hawkmoths (Hyles lineata), and small bees and flies [36], [39,40,41]
Plants participate in myriad interactions with microorganisms both above- and below-ground
Summary
Despite the growing number of studies documenting the proportions of plant species harboring microbes in their nectar and nectar microbial community composition, few studies have dissected spatial and temporal dynamics of nectar microbial occurrence and density in single plant species [12], [14], [15]. This limited number of studies has observed significant variation in microbial communities among flowers within plants, plants within populations, and among populations. Understanding the magnitude of such variation could have important implications for how plants interact with their pollinators [12], with subsequent effects on pollen flow, plant fitness, and patterns of pollinator-mediated natural selection
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
