Genetic causes and consequences of variation in sexual fertility among introduced populations of a clonal aquatic plant, Butomus umbellatus (Butomaceae)

The capacity for both sexual and clonal reproduction is widespread among perennial plants. The degree of sexuality may vary widely both within and between species, and this may, in turn, greatly influence the genetic diversity of populations. However, few studies have quantified variation in sexuality in clonal species or determined the underlying genetic and/or environmental factors or the population genetic consequences of sexual variation. In this study I investigated the geographical pattern of variation in sexual fertility as well as the genetic causes and consequences of sexual variation in the clonal aquatic plant, Butomus umbellatus (Butomaceae), across its adventive range in North America. I examined the population genetic consequences of variation in sexual fertility by comparing genotypic diversity at random amplified polymorphic DNA (RAPD) loci in five fertile vs. five sterile populations across the species' adventive range. I screened 20 individuals per population for eight RAPD primers (26 highly repeatable loci). (Abstract shortened by UMI.).