Genotype and spatial structure shape pathogen dispersal and disease dynamics at small spatial scales

Area of Science:

• Plant pathology
• Epidemiology
• Genetics

Background:

• Pathogen epidemics are often driven by passive dispersal, with variation typically linked to environmental factors.
• The genetic basis of pathogen dispersal at the microscale (< 2 m) remains largely unexplored.

Purpose of the Study:

• To investigate the role of genetic variation in the microscale dispersal of the wind-dispersed pathogen Podosphaera plantaginis.
• To determine how host and pathogen genotypes influence dispersal phases and disease development.

Main Methods:

• Laboratory inoculations, wind tunnel trials, and field experiments were conducted.
• The study analyzed the dispersal of Podosphaera plantaginis, focusing on departure, movement, and settlement phases.
• Genotypic variation in host and pathogen was assessed for its impact on dispersal.

Main Results:

• Recipient and source host genotypes, along with pathogen strain, significantly explained variation in dispersal.
• Genotypic variation was found to affect the group size of pathogen dispersal units.
• Increased disease development was observed on hosts located near the infection source due to dispersal variation.

Conclusions:

• Genetic variation plays a substantial role in the spatial and temporal spread of plant diseases.
• Disease hotspots can emerge around initial infection foci due to genotypic influences on dispersal.
• The identified genetic variation in dispersal traits suggests they are targets for natural selection.