Occurrence of postharvest gray mold rot of sweet cherry due to Botrytis cinerea in Korea

In May 2016, we observed gray mold rot symptoms on harvested and refrigerated cherry fruit in Gangneung, Gangwon Province, Korea. The symptoms included extensive growth of mycelia with gray conidia on infected fruit. We isolated the pathogen from infected fruit and cultured the fungus on potato dextrose agar. For identification of the fungus, we examined its morphology and rDNA sequence and confirmed its pathogenicity according to Koch’s postulates. The results of morphological examinations, pathogenicity tests, and rDNA sequence analysis of internal transcribed spacer regions 1 and 4, and three nuclear protein-coding genes, glyceraldehyde-3-phosphate dehydrogenase gene, heat shock protein 60 gene, and DNA-dependent RNA polymerase subunit II gene revealed that the causal agent was Botrytis cinerea. To our knowledge, this is the first report of postharvest gray mold rot of sweet cherry in Korea.