Sex allocation and reproductive success in the andromonoecious perennial Solanum carolinense (Solanaceae). I. Female success

Relative allocation of resources to growth vs, reproduction has long been k nown to be an important determinant of reproductive success. The importance of variation in allocation to different structures within reproductive all ocation is somewhat less clear. This study was designed to elucidate the im portance of allocation to vegetative vs. reproductive functions, and alloca tion within reproductive functions (sex allocation), to realized female suc cess in an andromonoecious plant, Solanum carolinense. Allocation measureme nts were taken on plants in experimental allays exposed to natural pollinat ion conditions. These measurements included total flower number; the propor tion of flowers that were male. Bower size. and vegetative size. Flower num ber explained the majority of the variation among individuals in their succ ess-that is, there was strong selection for increased Bower production. The re was also selection to decrease the proportion of flowers that were male, but neither flower size nor vegetative size (a measure of overall resource availability) were direct determinants of female success. After Bonferroni corrections for multiple comparisons. most phenotypic correlations among t he traits measured were nonsignificant. Thus, in this andromonoecious speci es there is not a strong relationship between resource availability (vegeta tive size) and female success, and female success is instead determined by the relative production of the two different flower types.