On the gynodioecious polymorphism in Saxifraga granulata L. (Saxifragaceae)

Abstract

Sexual and vegetative fitness components in hermaphrodite and female plants of the self-compatible, perennial herb Saxifraga granulata are compared using material derived from a gynodioecious population in northern England.

Females produced only 57% as many seeds as hermaphrodites, but their ovule offspring were 1.28 times as fit as those of hermaphrodites, and females were more vegetatively vigorous. The advantages to females in ovule offspring quality and in vegetative reproduction counteract their disadvantages in pollen and seed production and therefore probably play a role in the maintenance of the gynodioecious polymorphism. Pollination ecology, resource reallocation and inbreeding depression all appear to contribute to the observed sex differences in fitness.

Population biology, evolutionary genetics, natural selection, sexual polymorphism, gynodioecy, Saxifraga granulata