Sour cherry breeding – Resistance to leaf spot diseases, Blumeriella jaapii

Cherry leaf spot is one of the most serious fungal diseases of sour and sweet cherries. An artificial inoculation test method was established in the laboratory to evaluate resistance of cherry genotypes to the leaf spot fungus, Blumeriella jaapii. The reaction type to leaf spot of 52 sour cherry cultivars and 11 Prunus species was evaluated. In result 10 sour cherry cultivars showed a resistant reaction type to leaf spot. The tested Prunus species, P. canescens, P. incisa, P. kurilensis, P. maackii, P. nipponica, P. sargentii, P. serrulata ssp. spontanea, P. subhirtella showed a resistant reaction type to the leaf spot fungus. The species P. dawyckensis was susceptible.