LEVELS OF GENETIC-VARIATION AND COVARIATION FOR MIMULUS (SCROPHULARIACEAE) FLORAL TRAITS

In each of two populations of outcrossing Mimullus guttatus and selfin g M. micranthus we quantified genetic variation for floral traits whic h previously were shown to be associated with mating system evolution in this genus at both the population and species levels. Both broad- a nd narrow-sense heritabilities and genetic correlations were measured in greenhouse experiments. For one population of M. guttatus, we inves tigated and found significant among family variation for autogamous se ed-set in a pollinator-free environment, and this was weakly associate d with stigma-anther separation. We observed intermediate to high leve ls of broad- and narrow-sense heritabilities for all traits, but genet ic variation was consistently lower in the selfing species. Although c haracters correlated to stigma-anther separation or to day of first fl ower varied between populations and between taxa, there were consisten tly strong positive genetic correlations among traits associated with floral size.