The scope for sexual selection in plants

Introduction

The SEXIPLANTS project aims at providing a comprehensive empirical test for plants of the sexual selection theory and decipher the mechanisms underlying sexual selection in plants.

Background

Sexual selection, acting through competition for access to mates and their gametes, has successfully explained numerous reproductive strategies in animals. It typically emerges when females produce fewer numbers of larger gametes than males – a situation called anisogamy – which fosters competition among males for accessing the rare ovules.

Sexual selection theory should thus be universally valid for all sexually reproducing anisogamous organisms, including plants. While the idea that sexual selection acts on plants is largely accepted, most predictions of the sexual selection theory remain untested in the plant kingdom.

Research Approach

With a multi-method approach, including experimental evolution in the hermaphroditic plant Brassica rapa and comparative analyses in angiosperms, the SEXIPLANTS project addresses the following questions:

Q1. Testing the Theory

• Are fundamental predictions of sexual selection theory valid in the plant kingdom?
• We will empirically test key predictions of sexual selection theory regarding both male-male competition and female choice processes, and their demographic and genetic consequences.

Q2. Specificity

• Does the action of pollinators introduce specificity in the operation of sexual selection?
• We will empirically test how pollinator behavior and density can alter sexual selection.

Q3. Perception

• Can plants perceive and respond to variation in their mating opportunities?
• We will empirically test whether plants can plastically adjust their reproductive strategies to variation in competition for access to mates.

Conclusion

SEXIPLANTS will contribute to the development of a uniform and integrative theory of sexual selection valid for sexually-reproducing organisms, including plants, and potentially reform our conceptual understanding of plant reproduction, with implications for conservation.