Abstract

Floral traits endowing high reproductive fitness can also affect the probability of plants contracting sexually transmitted diseases. We explore how variations in floral traits influence the fitness of Silene dioica females in their interactions with pollinators carrying pollen or spores of the sterilizing anther-smut fungus Microbotryum violaceum.We collected healthy and infected plants in a highly diseased population and grew them under conditions that 'cure' infected individuals, and used standard regression methods to detect natural selection on floral traits. Narrow-sense heritabilities, coefficients of additive genetic variation (CVA) and genetic correlations among traits were estimated from paternal half-sib groups.Pollinator preferences imposed strong direct and directional selection on traits affecting female attractiveness and pollen-/spore-capturing abilities. Levels of additive genetic variance were high in these traits, suggesting that rapid responses to selection are possible.By considering our results in the light of spatial and temporal heterogeneity resulting from the colonization dynamics typical for this species, we suggest that the conflicting selective effects of pollen/spore loads lead to the maintenance of genetic variation in these traits.

Keywords

additive variance; floral evolution; maintenance of genetic variation; Microbotryum violaceum (anther smut); phenotypic selection; pollinators; Silene dioica (red campion)

Published in

New Phytologist
2006, Volume: 169, number: 4, pages: 729-739
Publisher: BLACKWELL PUBLISHING

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1111/j.1469-8137.2005.01544.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/84129