ABSTRACT
Background According to sexual selection theory, males compete with each other over access to females since the reproductive success of a male is limited by the number of females he can fertilize, whereas female reproductive success is limited by resources available for producing ospring [1,2]. In plants, access to pollinators should therefore limit the reproductive success of males to a greater extent than it restricts the reproductive success of females [3-5]. Consequently, dierent selection pressures are expected to act on males and females, resulting in male-male competition over mates [1].
