Different systems of mating can have profound consequences for the adaptive potential of species. Despite the demonstrable genetic advantages of outcrossing, a significant proportion of plant species self-fertilize occasionally or habitually. This proposal aims to accurately reconstruct the history of mating system variation in Solanaceae, an economically important plant family. The proposal identifies a new approach to reconstruction of mating system ancestry, using a common genetic system involved prevention of self-fertilization. This genetic system, called self-incompatibility, prevents a hermaphrodite plants own pollen from fertilizing its ovules. This proposal unites a framework of ideas from molecular genetics, theoretical population biology, and statistical methods to develop a tests of hypotheses of a) irreversibility of mating system characters and b) the effects of a widespread mating system character on species diversification rates. Thus, the ultimate goal of this study is the understanding of how mating systems affect the multiplication and survival of plant species, one of the most diverse and important groups of terrestrial organisms.
