Sexual selection and sexual conflict theories that explain evolution of sexual behaviour are often an integral part of animal studies investigating diverse research questions, e.g. in behaviour, ecology, physiology and immunology. In plants, however, relatively few studies investigate sexual selection and sexual conflict. In this review we discuss how taking these theories into account can be useful not only for our understanding of plant reproductive strategies but also in related research areas, including i) mechanisms of pollen-pistil interactions, ii) mating-system evolution in hermaphrodites and iii) plant immune responses to pests and pathogens.
Today it is accepted that the theories of sexual selection and sexual conflict are general and can be applied to both animals and plants. However, potentially due to a controversial history, plant studies investigating sexual selection and sexual conflict are relatively rare. Moreover, these theories and concepts are seldom implemented in research fields investigating related aspects of plant ecology and evolution. Even though these theories are complex, and can be difficult to study, we suggest that several fields in plant biology would benefit from incorporating and testing the impact of selection pressures generated by sexual selection and sexual conflict. Here we give examples of three fields where we believe such incorporation would be particularly fruitful, including (i) mechanisms of pollen–pistil interactions, (ii) mating-system evolution in hermaphrodites and (iii) plant immune responses to pests and pathogens.