Anther-Smut Infection in Silene dioica: Variation in Floral Morphology and Patterns of Spore Deposition

Abstract

The anther-smut Microbotryum violaceum, causes a systemic perennial infection of its host Silene dioica. Infection results in sterility and the production of teliospores in flowers. These spores are transmitted to healthy plants by flower visiting insects. The behavioural responses of flower visiting insects to a variation in floral characters are therefore likely to affect rates of pollen export/import, the rate of spore deposition and probability of disease. Since infected plants are sterilised, they are effectively removed from the gene pool. It is therefore often assumed that in this host-pathogen system there is a considerable potential for a pathogen-pollinator mediated selection on floral characters