Influence of plant domestication on plant-pollinator interactions: floral attributes and floral visitor communities in wild and cultivated squash plants.

Abstract

Domestication of plant species results in phenotypic modifications and changes in biotic interactions. Most studies have compared antagonistic plant-herbivore interactions of domesticated plants and their wild relatives, but little attention has been given to how domestication influences plant-pollinator interactions. Floral attributes and interactions of floral visitors were compared between sister taxa of the genus Cucurbita (Cucurbitaceae), the domesticated C. moschata, C. argyrosperma ssp. argyrosperma and its wild progenitor C. argyrosperma ssp. sororia in the place of origin. We conducted univariate and multivariate analyses to compare floral morphological traits and analyzed floral reward (nectar and pollen) quantity and quality between flowers of wild and domesticated cucurbits. Staminate and pistillate flowers of all three taxa were video recorded, and visitation and behavior of floral visitors were registered and analyzed. Most floral morphological characteristics of flowers of domesticated taxa were larger in both staminate and pistillate flowers. Staminate and pistillate flowers presented distinct correlations between floral traits and integration indices between domesticated and wild cucurbits. Additionally, pollen quantity and protein to lipid ratio were greater in domesticated cucurbits. Cucurbit pollen specialists, Eucera sp., had the highest probability of visit for all cucurbit taxa. We provide evidence that floral traits of domesticated and wild cucurbit plants experienced different selection pressures. Domesticated cucurbit plants may have more resources invested towards floral traits, thereby increasing attractiveness to pollinators and potentially plant reproductive success. Wild ancestor plant populations should be conserved in their center of origin to preserve plant-pollinator interactions. This article is protected by copyright. All rights reserved.