Abstracts (first author)
Genotype and spatial structure shape pathogen dispersal and disease dynamics at small spatial scales
Many devastating pathogens are passively dispersed, and their epidemics are characterized by variation that is typically attributed to environmental factors. Here, by combining laboratory inoculations with wind tunnel and field trials using the wind-dispersed pathogen Podosphaera plantaginis, we demonstrate striking genetic variation affecting the unexplored microscale (<2 m) of epidemics. Recipient and source host genotypes, as well as pathogen strain explain 6-33% of variation of the three key dispersal phases: departure, movement and settlement. Moreover, we find genotypic variation affecting group size of the pathogen dispersal unit, ultimately resulting in increased disease development on hosts nearby the infection source. Together, our results show that the genotypic variation may generate considerable variation in the rate of disease spread through space and time with disease hotspots evolving around initial foci. Furthermore, the extent of genetic variation affecting the entire dispersal process confirms that these traits may be targeted by selection.