Variation Of Floral Traits In Trollius Ranunculoides And The Role Of Pollinators

The causal role played by animal pollinators in the extraordinary diversification of angiosperm flowers has figured prominently in plant biology.However,the selection of animal pollinators on floral traits involves the spatial and temporal variation in selection on a given trait.Unless selection is measured on different spatial scales and temporal scales,an assessment of the strength and nature of selection may be incomplete.We selected Trollius ranunculoides as experimental material,analyzed selection of pollinators on flower traits on different spatial scales and time scales,and studied the reproductive strategies.Among different populations,we found significant variations of floral traits and pollinator assemblages and visiting frequency among populations.The intensity of pollinator selection on the length and width of calyx became stronger with the elevation increasing,which means larger attraction to pollinators of large calyx at high-elevational population of Trollius ranunculoides.Among different flowering time,within population,we found significant differences of floral traits among different flowering time,and pollinators visiting frequencies were also different.However,the intensity of selection by pollinators on plant characteristic were different at different flowering time.The impact of environmental factors on plant reproductive allocation and the role of pollinators together determine the flower variation of Trollius ranunculoides at different flowering time within populations.