Abstract
Studies on the selection of floral traits usually consider pollinators and sometimes herbivores. However, humans also exert selection on floral traits of ornamental plants. We compared the preferences of bumblebees (Bombus terrestris), thrips (Frankliniella occidentalis), and humans for flowers of snapdragon. From a cross of two species, Antirrhinum majus and Antirrhinum linkianum, we selected four Recombinant Inbred Lines (RILs). We characterised scent emission from whole flowers and stamens, pollen content and viability, trichome density, floral shape, size and colour of floral parts. We tested the preferences of bumblebees, thrips, and humans for whole flowers, floral scent bouquets, stamen scent, and individual scent compounds. Humans and bumblebees showed preferences for parental species, whereas thrips preferred RILs. Colour and floral scent, in combination with other floral traits, seem relevant phenotypes for all organisms. Remarkably, visual traits override scent cues for bumblebees, although, scent is an important trait when bumblebees cannot see the flowers, and methyl benzoate was identified as a key attractant for them. The evolutionary trajectory of flowers is the result of multiple floral traits interacting with different organisms with different habits and modes of interaction.
Highlights
The floral phenotype is shaped by diverse selective forces including pollinators and pests, and – at least in the case of ornamental flowers – humans (Gessert, 1993; Ågren, 2019; Ramos and Schiestl, 2019)
In the case of ornamental flowering plants, which are presumably selected by humans, biotic selection of the floral phenotype is affected by the perception and preferences of the tripartite forces of humans, florivores, and pollinators
The assessment of the preferences of bumblebees for whole flowers showed that they made more choices for A. linkianum (Wilcoxon v = 21, p = 0.035) and Recombinant Inbred Lines (RILs) 112 flowers (Wilcoxon v = 45, p = 0.009), than A. majus blossoms
Summary
The floral phenotype is shaped by diverse selective forces including pollinators and pests, and – at least in the case of ornamental flowers – humans (Gessert, 1993; Ågren, 2019; Ramos and Schiestl, 2019). Plants need to find a balance between attracting pollinators and repelling antagonists (Junker and Blüthgen, 2010). Both pollinators and herbivores exert pressures on the selection of floral traits, driving the evolution of angiosperms in natural ecosystems. In the case of ornamental flowering plants, which are presumably selected by humans, biotic selection of the floral phenotype is affected by the perception and preferences of the tripartite forces of humans, florivores, and pollinators
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
