The cultivation of melon (
Cucumis melo
L.) in
greenhouses has contributed to the increased incidence of
fungal diseases, particularly gummy stem blight caused
by
Didymella bryoniae (Fuckel) Rehm. This disease is
currently considered the main disease affecting this crop,
causing conditions such as water soaked seedlings, and
stem and fruit cankers, reducing productivity and fruit
quality. Considering the importance of this disease, the
aim of this study was to evaluate the reaction of different
C. melo genotypes to
D. bryoniae. Sixty-eight different
melon genotypes were investigated. Two phenotyping
assays were performed to investigate the resistance to the
disease, following a randomized block design with four
replicates. Subsequently, a new assay was conducted to
validate the resistance of the genotypes selected in the
previous step, using a randomized block design with three
replicates. The plants were inoculated using the toothpick
method, and resistance was evaluated according to a
grading scale. Also, reaction classes and assay groups were
used for classifying the resistance level of the genotype.
The JAB-11 and JAB-20 strains were susceptible to the
pathogen, as well as the commercial hybrids Louis F
1 and
Fantasy F
1. The hits AC-29, C160, Charentais Fom 1, PI
420145, PI 482398 and PI 532830 were resistant to
D.
bryoniae, and could become an important gene source for
the development of resistant cultivars.
