Polymorphism for disease resistance in the annual legume amphicarpaea bracteata

Abstract

Amphicarpaea bracteata plants from a single population varied greatly in disease resistance when inoculated with six different strains of the specialist pathogen Synchytrium decipiens collected from the same site. Seifed progenies of two plants exhibited heterogeneity in disease resistance. Inoculation experiments indicated that variation in disease resistance in these plant families was controlled by a single locus, with resistance exhibiting nearly complete dominance. This resistance factor was effective against only a limited number of the pathogen genotypes present in this area. Thus, its selective value will depend on the genetic structure of the pathogen population, which may result in frequency-dependent fitness variation for this trait. © The Genetical Society of Great Britain.