Data from: Do plant pathogens prefer seedlings? Variation in age specific infectivity across pathogen genotypes

Across plant and animal species, juveniles are generally more susceptible
to infectious pathogens than adults. A growing body of research has
explored how age-specific resistance evolves and why juvenile
susceptibility is maintained in host populations. From the less
well-studied pathogen’s perspective, juvenile susceptibility means that
most pathogens infect juvenile hosts more readily than adult hosts. In the
present study, we investigated whether this pattern of age-specific
infectivity varied across pathogen genotypes within a fungal pathogen
species (Microbotryum lychnidis-dioicae) infecting a plant host (Silene
latifolia). We inoculated four host genotypes with each of five pathogen
genotypes at two different host ages (seedling and adult) and scored the
proportion infected for each host genotype*pathogen genotype combination.
The data set contains the total number of plants scored and the number
that were infected for each GxG combination.  We also recorded
the sex of each individual disease plant, and this information is also
included in the data set.   We found significant
interactions between pathogen genotype and host age, indicating variation
in age-specific infectivity, and suggesting that this important
epidemiological trait can evolve in response to selection. Furthermore, we
found that significant pathogen × host genotype interactions determine
infection risk for juvenile hosts and vegetative adults, whereas infection
risk for reproductive adults is primarily determined by the main effects
of pathogen and host genotypes. This suggests that specific immunological
interactions may be the main determinants of resistance for juveniles and
nonreproductive adults. In contrast, more general resistance mechanisms,
such as physical barriers, may be the primary resistance mechanisms in
reproductive adults.