The transmission of genes via pollen and ovules in gynodioecious angiosperms

Gynodioecy is defined as the class of sexual dimorphism in which females are constant (functionally unisexual) and males are inconstant (bisexual). Quantitative measures describe the sexual performance of males in gynodioecious populations. The relative (male/female) ovule contribution compares the ovule contributions of the sexes to the next generation. Male constancy and inconstancy, the proportions of male genes transmitted via pollen and ovules, are direct measure of maleness and femaleness. Equations permitting the values of the sex parameters to be estimated are derived. The values obtained for twelve species show that gynodioecy is not a single breeding system, but merges into hermaphroditism and dioecy at opposite extremes. The distribution of inconstancies among individual males is described for six species. In most species, seed counts overestimate the ovule contributions of males.