Data from: Measurement of infection efficiency of a major wheat pathogen using time-resolved imaging of disease progress

Infection efficiency is a key epidemiological parameter that determines
the proportion of pathogen spores able to infect and cause lesions once
they have landed on a susceptible plant tissue. In this study, we present
an improved method to measure infection efficiency of Zymoseptoria tritici
using a replicated greenhouse experiment. Z. tritici is a fungal pathogen
that infects wheat leaves and causes Septoria tritici blotch (STB), a
major disease of wheat worldwide. We devised an original experimental
setup, where we (i) attached living wheat leaves to metal plates allowing
for time‐resolved imaging of disease progress in planta. Since lesions
were continuously appearing, expanding and merging during the period of up
to three weeks, daily measurements were necessary for accurate counting of
lesions. We also (ii) used reference membranes to characterize the density
and the spatial distribution of inoculated spores on leaf surfaces. In
this way, we captured the relationship between the number of lesions and
the number of viable spores deposited on the leaves and estimated the
infection efficiency of about 4% from the slope of this relationship. Our
study provides a proof of principle for an accurate and reliable
measurement of infection efficiency of Z. tritici. The method opens
opportunities for determining the genetic basis of the component of
quantitative resistance that suppresses infection efficiency. This
knowledge would improve breeding for quantitative resistance against STB,
a control measure considered more durable than deployment of major
resistance genes.