Phenotypic natural selection on flower biomass allocation in the tropical treeIpomoea wolcottiana Rose (Convolvulaceae)

Intra-population patterns of phenotypic variation in biomass allocation to flower parts are analyzed for the treeIpomoea wolcottiana, and the effects of this variation on fruit production are evaluated in two consecutive years. Significant variation among individuals was found for biomass of both sexual and attractive structures. Repeatability values showed that variation in these structures could be heritable. Analyses of phenotypic natural selection indicated a positive directional selection for both, gynoecium and petals mass in both years. These results suggest that floral resource allocation can be modified by phenotypic natural selection. To our knowledge this is the first paper that reports phenotypic natural selection in floral characteristics of a tropical tree species.