Diversity and Host Associations of the Genus Colletotrichum in Korea

Colletotrichum is one of the most economically important genera of plant pathogenic fungi worldwide, yet its species diversity and host associations remain incompletely understood in many regions. In Korea, historical records based largely on morphological identification have underestimated species diversity and obscured host-association patterns. In this review, we provide an integrative reassessment of Colletotrichum diversity and host associations in Korea, combining published literature with recent taxonomic re-evaluations of 237 Colletotrichum isolates preserved in the Korean Agricultural Culture Collection. Of the 86 Colletotrichum species reported in Korea, 73 are currently accepted species worldwide; 61 are supported by DNA sequence data and belong to 15 species complexes and one singleton lineage, whereas the remaining records require taxonomic verification. Among the KACC isolates, 52 species are represented, comprising 36 species previously reported from Korea, 14 species newly recorded in Korea, and two newly described species. Our synthesis reveals extensive historical misidentification uncovered by multilocus re-evaluation. The 61 molecularly identified species are associated with 120 plant species across 102 genera and 54 families, forming 203 validated fungus-host combinations. Among the recorded species complexes, the C. gloeosporioides and C. acutatum complexes have the largest numbers of host associations in Korea. Major crops associated with Colletotrichum include pepper, apple, grape, persimmon, strawberry, peach, and ginseng, each often harboring multiple distinct Colletotrichum species. These findings underscore how advances in molecular systematics have substantially reshaped our understanding of Colletotrichum diversity and host associations in temperate agroecosystems.