Floral dimorphism, pollination, and self-fertilization in gynodioecious <i>Geranium richardsonii</i> (Geraniaceae)
Abstract
The selective maintenance of gynodioecy depends on the relative fitness of the male‐sterile (female) and hermaphroditic morphs. Females may compensate for their loss of male fitness by reallocating resources from male function (pollen production and pollinator attraction) to female function (seeds and fruits), thus increasing seed production. Females may also benefit from their inability to self‐fertilize if selfing and inbreeding depression reduce seed quality in hermaphrodites. We investigated how differences in floral resource allocation (flower size) between female and hermaphroditic plants affect two measures of female reproductive success, pollinator visitation and pollen receipt, in gynodioecious populations of Geranium richardsonii in Colorado. Using emasculation treatments in natural populations, we further examined whether selfing by autogamy and geitonogamy comprises a significant proportion of pollen receipt by hermaphrodites. Flowers of female plants are significantly smaller than those of hermaphrodites. The reduction in allocation to pollinator‐attracting structures (petals) is correlated with a significant reduction in pollinator visitation to female flowers in artificial arrays. The reduction in attractiveness is further manifested in significantly less pollen being deposited on the stigmas of female flowers in natural populations. Autogamy is rare in these protandrous flowers, and geitonogamy accounts for most of the difference in pollen receipt between hermaphrodites and females. Female success at receiving pollen was negatively frequency dependent on the relative frequency of females in populations. Thus, two of the prerequisites for the maintenance of females in gynodioecious populations, differences in resource allocation between floral morphs and high selfing rates in hermaphrodites, occur in G. richardsonii.
Local Knowledge Graph (9 entities)
Related Works
Items connected by shared entities, co-authorship, citations, or semantic similarity.
The role of fly pollination in montane habitats
Vegetation and environmental patterns in the Crested Butte area, Gunnison County, Colorado
Pollinator choice of flower size and sexual morph in <i>Geranium richardsonii</i>
Data from: Effects of soil resources on expression of a sexual conflict over timing of stigma receptivity in a mixed-mating plant
Data from: Influence of plant reproductive systems on the evolution of hummingbird pollination
Ecological causes and consequences of flower color polymorphism in a self-pollinating plant (Boechera stricta)
Growing Colorado Plants From Seed: State of the Art Volume III
Shrubland Ecosystem Genetics And Biodiversity: Proceedings
Southwestern Rare and Endangered Plants: Proceedings of the Third Conference
Cited By (81 times, 4 in Knowledge Hub)
Sex ratio and reproductive success along elevational gradients of gynodioecious populations of <i>Geranium richardsonii</i>
Expansion of herbaria data based on historically surveyed herbaceous plants in the Crested Butte area, Colorado.
Effects of quantity and distribution of pollen on fertilization in the gynodioecious species <i>Geranium richardsonii</i>
The effect of hermaphrodite density and frequency at three spatial scales on the polen receipt and seed set of gynodioecious Geranium richardsonii (Geraniaceae)
References (53)
2 in Knowledge Hub, 51 external