9307823 Kesseli The long term objectives are to define the genetic changes and evolutionary processes that lead to dioecy (separate male and female individuals in a population) and to understand the common factors that may be responsible for the repeated occurrence of the dioecious reproductive strategy among living organisms. %%% Specifically the genetic bases for the evolution of dioecy in the plant genus Silene is explored. Four short term objectives will be pursued. The first is to develop genetic maps for the sex chromosomes of the dioecious plant species Silene latifolia and S. otitis. The second is to evaluate gender stability and potential shifts in breeding system in the genus. The third is to characterize and define the organization of the genus responsible for sex determination. The fourth is to compare the architecture of these genes among related dioecious species and hermaphroditic species which lack separate sexes and sex chromosomes.
