Abstract
Host-pathogen interactions display a continuum of host ranges from extreme specialists limited to single hosts to broad generalists with hundreds of hosts. However, the existing models for host-pathogen dynamics are dominated by observations derived from specialist pathogens with qualitative virulence and tight host-pathogen co-evolution. It is not clear how appropriate the co-evolutionary model is in generalist pathogens that present quantitative virulence and broad host specificity. We infected 98 strains of the generalist necrotroph fungus Botrytis cinerea on 90 genotypes representing eight plant species with wild and domestic lines. We show that plant-Botrytis interactions don’t fit traditional co-evolution models as Botrytis interacts with the Eudicot species individually, with little link to the relatedness between plant species or plant domestication. Furthermore, Botrytis host specificity and virulence have distinct polygenic architectures suggesting that the evolution of the Eudicot/Botrytis interactions relies on genome-wide allelic diversity rather than few major virulence loci.
Footnotes
The discussion was expanded
