Identification and Characterization of Postharvest Apple Rot caused by Fusarium tricinctum and Alternaria alternata

Abstract

Postharvest apple rot causes severe economic losses and lowers apple quality, and is one ofthe most important limiting factors of apple exports. Apples with rot symptoms were sampledfrom Geochang, South Korea. Isolation of the causal fungus was performed by culturing smallpieces of diseased tissues on potato dextrose agar. Two different rot genera, Fusarium andAlternaria, were identified according to their morphological characteristics. To confirm theidentity of the causal fungus, we sequenced the DNA of the complete internal transcribedspacer(ITS) rDNA gene region and translation elongation factor 1-alpha(EF1-α) region. Koch’spostulates were supported by pathogenicity tests conducted on apple fruit. Based on mycologicalcharacteristics, molecular identification, and pathogenicity tests, the two fungi were identified asFusarium tricinctum and Alternaria alternata. To the best of our knowledge, this is the firstreport of postharvest apple rot caused by F. tricinctum and A. alternata in South Korea.