Abstract

Female choice is a central process of sexual selection that has shaped numerous phenotypes in animals. It may operate broadly across sexually reproducing organisms, including plants, not only because sex differences in sexual selection arise from anisogamy, wich refers to the unequal investment in gametes between sexes, but also because it can emerge from simple variation in female reproductive morphology. Here, we provide the first empirical test of cryptic female choice in an angiosperm by examining whether pollen and pistil traits jointly influence paternal fertilization success. Using experimental pollen competition, paternity analyses, and trait measurements, we show that pistil traits can bias paternity toward pollen donors with specific pollen traits. These results demonstrate that cryptic female choice operates in plants, paralleling mechanisms described in animals.