• The Korean Journal of Mycology
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• v.52 no.2
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• pp.109-114
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• 2024

Anthracnose fruit rot (AFR) has been observed in greenhouses during the harvesting period in the Chungnam Province of South Korea. Fruits infected inside the greenhouse show black or brown spots, orange conidial masses and in some areas of the infected parts, white fungal growths are visible. The size of these spots gradually expands, leading to the necrosis of the fruits and flowers. Three isolates were obtained from infected fruits and identified as strains of the Colletotrichum acutatum species complex based on morphological characteristics. Multilocus sequence analysis of actin, chitin synthase, glyceraldehyde-3-phosphate dehydrogenase genes, and internal transcribed spacer rDNA regions revealed that the isolates belong to a monophyletic group with the type strain of C. nymphaeae. This is the first time C. nymphaeae has been confirmed in strawberry fruit in Korea.

• Research in Plant Disease
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• v.29 no.4
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• pp.345-362
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• 2023

Anthracnose, caused by the Colletotrichum genus, comprises a significant number of plant pathogens and poses a major threat to fruit production worldwide, including South Korea. Colletotrichum species were identified associated with anthracnose in fruits such as apple, persimmon, plum, peach, jujube, walnut, and grape. A polyphasic approach, including morphology, multigene phylogenetics, and pathogenicity testing, was used. Additionally, the in-vitro sensitivity of identified Colletotrichum species to common fungicides was also evaluated. A total of nine Colletotrichum species within two complexes, namely gloeosporioides and acutatum, have been identified as the causal agents of anthracnose in common fruits in South Korea. In the gloeosporioides complex, we found Colletotrichumaenigma, C. fructicola, C. gloeosporioides, C. horii, C. siamense, and C. viniferum. Meanwhile, in the acutatum complex, C. fioriniae, C. nymphaeae, and C. orientalis were identified. Notably, C. fructicola, C. siamense, C. fioriniae, and C. nymphaeae were reported for the first time from apple, C. siamense, C. fioriniae and C. nymphaeae from plum, C. siamense, C. fructicola, and C. fioriniae frompeach, C. siamense and C. horii from persimmon, C. fioriniae from Omija (Schisandra), C. orientalis from walnut, C. nymphaeae from jujube, and C. aenigma, C. fructicola, and C. siamense fromgrape. Fungicide sensitivity tests revealed significant variation in the EC₅₀ values among specific Colletotrichum species when exposed to different fungicides. Moreover, the same Colletotrichum species isolated from different host plants displayed varying sensitivity to the same fungicide.

• The Plant Pathology Journal
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• v.34 no.6
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• pp.480-489
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• 2018

Bitter rot caused by Colletotrichum species is a common fruit rotting disease of apple and one of the economically important disease in worldwide. In 2015 and 2016, distinct symptoms of bitter rot disease were observed in apple orchards in five regions of South Korea. In the present study, infected apples from these regions were utilized to obtain eighteen isolates of Colletotrichum spp. These isolates were identified and characterized according to their morphological characteristics and nucleotide sequence data of internal transcribed spacer regions and glyceraldehyde-3-phosphate-dehydrogenase. Molecular analyses suggested that the isolates of Colletotrichum causing the bitter rot disease in South Korea belong to 4 species: C. siamense; C. fructicola; C. fioriniae and C. nymphaeae. C. siamense and C. fructicola belonged to Musae Clade of C. gloeosporioides complex species while C. fioriniae and C. nymphaeae belonged to the Clade 3 and Clade 2 of C. acutatum complex species, respectively. Additionally, we also found that the isolates of C. gloeosporioides species-complex were more aggressive than those in the C. acutatum species complex via pathogenicity tests. Taken together, our results suggest that accurate identification of Colletotrichum spp. within each species complex is required for management of bitter rot disease on apple fruit in South Korea.

• Journal of Forest and Environmental Science
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• v.37 no.2
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• pp.154-162
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• 2021

Blueberry, which produces phenolic compounds, is one of the most popular fruits in Korea. During a survey on blueberry diseases, 16 Colletotrichum isolates were obtained from blueberry leaves in Chuncheon and Gosung, Kangwon province, Korea. Using morphological and molecular analyses, the isolates were identified as Colletotrichum aenigma, C. fioriniae, C. fructicola, C. gloeosporioides, and C. nymphaeae. C. gloeosporioides was the most frequently isolated (11 isolates), and only one or two isolates of the other species were found. After inoculation with all isolates, those leaves and fruits with wounds easily developed anthracnose; whereas, fruits without wounds became infected but leaves without wounds were infected by only two of C. gloeosporioides. Typically, around seven fungicidal agents are used to control anthracnose on blueberries in Korea. Fluzinam and prochloraz manganese complex strongly (over than 80%) inhibited the growth of all Colletotrichum species, while dithianon and mancozeb only weakly (about 80% or less) inhibited their growth.

• The Plant Pathology Journal
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• v.39 no.4
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• pp.384-396
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• 2023

Colletotrichum acutatum species complex is one of the most important groups in the genus Colletotrichum with a high species diversity and a wide range of host plants. C. acutatum and related species have been collected from different plants and locations in Korea and deposited into the Korean Agricultural Culture Collection (KACC), National Institute of Agricultural Sciences since the 1990s. These fungal isolates were previously identified based mainly on morphological characteristics, and a limitation of molecular data was provided. To confirm the identification of species, 64 C. acutatum species complex isolates in KACC were used in this study for DNA sequence analyses of six loci: nuclear ribosomal internal transcribed spacers (ITS), betatubulin 2 (TUB2), histone-3 (HIS3), glyceraldehyde3-phosphate dehydrogenase (GAPDH), chitin synthase 1 (CHS-1), and actin (ACT). The molecular analysis revealed that they were identified in six different species of C. fioriniae (24 isolates), C. nymphaeae (21 isolates), C. scovillei (12 isolates), C. chrysanthemi (three isolates), C. lupini (two isolates), and C. godetiae (one isolate), and a novel species candidate. We compared the hosts of KACC isolates with "The List of Plant Diseases in Korea", previous reports in Korea and global reports and found that 23 combinations between hosts and pathogens could be newly reported in Korea after pathogenicity tests, and 12 of these have not been recorded in the world.