Peroxidase activity as a biochemical marker for resistance of muskmelon (Cucumis melo) to Pseudoperonospora cubensis

Peroxidase activity in uninfected muskmelon plants was used to predict the resistance and susceptibility of 257 plants, including cultivars or breeding lines and crosses of susceptible and resistant plants. When values of peroxidase activity greater than or equal to 30 (changes in absorbance at 470 nm min -1 g -1 fresh weight of leaf tissue) were used, 100% of the resistant plants were detected, whereas at values of less than 30, 89% of the susceptible plants were detected (...)