EVOLUTION OF REPRODUCTIVE SYSTEMS IN THE GENUS SILENE

The genus Silene contains both hermaphrodite, gynodioecious and dioeci ous species, dioecy being represented in three sections of the genus. To locate the events of change of reproductive systems, we compared IT S sequences of 22 species of Silene chosen throughout the whole genus, and four putative outgroup species. Gynodioecy, which is the most com mon reproductive system within the genus Silene and in closely related genera such as Saponaria and Dianthus, is proposed to be ancestral in the genus. Dioecy has evolved at least twice: once in the section con taining S. latifolia, and once in the clade containing S. otites and S . acaulis ssp. bryoides. Evolution towards hermaphroditism, associated with evolution of selfing, has also occurred at least twice, in S. ga llica and S. conica.