Data from: Effect of expanded variation in anther position on pollinator visitation to wild radish, Raphanus raphanistrum
Sapir, Yuval et al. (2018), Data from: Effect of expanded variation in anther position on pollinator visitation to wild radish, Raphanus raphanistrum, Dryad, Dataset, https://doi.org/10.5061/dryad.1gc03
Background and Aims: Plant-pollinator interactions shape the evolution of flowers. Floral attraction and reward traits have often been shown to affect pollinator behavior, but the possible effect of efficiency traits on visitation behavior has rarely been addressed. Here we tested for the effect of anther position, usually considered a trait that influences efficiency of pollen deposition on pollinators, on pollinator visitation rates and visit duration in flowers of wild radish, Raphanus raphanistrum. Methods: We used artificial selection lines from two experiments that expanded the naturally-occurring phenotypic variation in anther position. In one experiment, plant lines were selected to either increase or decrease anther exsertion. The other experiment decreased anther dimorphism, which resulted in increased short stamen exsertion. We hypothesized that increased exsertion will increase visitation of pollen foragers due to increased visual attraction. We also hypothesized that exsertion of anthers above the corolla would interfere with nectar foragers and increase time of visit per flower. Key Results: In the exsertion selection experiment, increased exsertion of both short and long stamens resulted in an increased number of fly visits per plant, and in the dimorphism experiment bee visits increased with increased short stamen exsertion. Duration of nectar feeders declined significantly with increasing long stamen exsertion, as opposed to the hypothesis. Conclusions and synthesis: Until now, anther position was considered an efficiency trait to enhance pollen uptake and deposition. We show that anther position in wild radish has an ecological significance also in attracting pollen foragers. This study suggests an additional adaptive role for anther position beyond efficiency, and highlights the multiple ecological functions of floral traits in plant-pollinator interactions.