The present study aims to develop a CFI-based system for rapid
and objective analysis of potential Bremia resistance in young
plants of newly bred lettuce lines. This new approach adapts to a
yet existing standard test procedure, which applies the inoculation
of leaf discs with various Bremia lines and their incubation on layers
of wet filter paper in a high humidity environment for 14 days.
The image analysis method of cumulative Fv/Fm (Bauriegel et al.,
2010) was used to evaluate the temporal and spatial dynamics of
specific changes in photosynthetic competence of plants of ten
sensitive and resistant butterhead and batavia lettuce lines. These
changes are a valid indicator of the adverse effects of a successful
Bremia infection on plants physiology in susceptible lettuce cultivars
and lines. Furthermore, efficient adaption of the new assessment
system to the standard visual resistance check technique
also implies an improvement of the basic measurement procedure,
including the optimisation of the underlay of leaf discs.