Allocations to Pollen, Seeds and Pollination Mechanisms in Self-Fertilizing Plants

Phenotypic models of selection are used to predict the ESS (evolutionarily stable strategy) allocation to pollen, seeds and pollination mechanisms (corolla, etc.) as a function of the frequency of self-fertilization in plants with different modes of self-fertilization. The results show that: (1) As autogamous self-fertilization increases, the ESS allocation to seeds increases and the allocations to pollen and pollination mechanisms simultaneously decrease. (2) Whether or not there is any allocation to pollination mechanisms with 100% selfing depends on whether self-pollination requires the activity of pollinators or occurs autonomously. (3) The best measure of the importance of self-fertilization is the proportion of adults derived from selfing. (4) If any autogamy occurs, the allocations to pollen and seeds are not equivalent to those to male and female functions. (5) Self-fertilization is not a special case of local mate competition. (6) Geitonogamous self-fertilization requires the same structures as outcrossing and has little effect on allocations. The models can explain the allocation patterns and high fruit set commonly associated with self-fertilization and they suggest further types of data that should be collected. Key-words: Allocations, self-fertilization, sexual strategies, plants, pollen, seeds, pollination