Domestication drives changes in floral functional traits that impact generalist pollinator visitation

Abstract

Crop domestication is an evolutionary process that has led to extraordinary plant phenotypic changes in response to artificial selection. The extent to which domestication has altered floral phenotypes and the implications of these changes for plant-pollinator interactions remain unclear. Here, we characterized the floral phenotypes of wild and domesticated species in the genus Cucurbita (squash and pumpkins) and quantified their relative attractiveness to generalist and specialist pollinators. Our results show that functional floral traits change with domestication and that some of these changes impact the visitation of generalist pollinators but not specialists. Crops displayed larger flowers with shorter anthers and wider corollas, lower volatile richness, higher sugar content in pollen, and lower sucrose:glucose ratios in nectar. These trait shifts were associated with pollinator behavior in generalist pollinators, which preferentially visited domesticated flowers. We demonstrate that domestication alters functional plant traits and that these changes affect generalist pollinator preference in agricultural settings.