Evolution of Breeding Systems in Asteraceae
SEXAS
Although most angiosperms are hermaphroditic, other breeding systems (andromonoecy, gynomonoecy, monoecy, androdioecy, gynodioecy, subdioecy, dioecy, Richards, 1997) have evolved in many lineages. This is true from Asteraceae, where hermaphroditic, andromonoecious, gynomonoecious, monoecious, gynodioecious and dioecious taxa are found.
The aim of this project is to study the evolution of these non-hermaphroditic breeding systems in Asteraceae. The specific objectives of the project are:
By using phylogenetic supertrees and comparative methods, to assess how many independent times these non-hermaphroditic breeding systems have evolved, and to find out the pathways followed in the evolution of dioecy (through monoecy or through gynodioecy; Freeman et al., 1997).
To assess whether current position effects in the gender of flowers within the capitula are remnants of the mechanisms that led to the evolution of non-hermaphroditic breeding systems, by comparing the performance of seeds coming from different positions of the capitulum in a range of species with contrasting breeding systems.
To study the ecological factors which influence male and female reproductive success in species with different breeding system (gynomonoecy, monoecy, gynodioecy, dioecy) in order to assess the selective pressures which have led to the evolution of those breeding systems.
References
Richards, A.J.1997. Plant Breeding Systems. 2 ed. Chapman and Hall. London.
Freeman, D. C., Doust, J. L. L., El-Keblawy, A., Miglia,K. J. & McArthur, E. D. 1997. Sexual specialization and inbreeding avoidance in the evolution of dioecy. Bot. Rev. 63, 65–92.