Colletotrichum kakivorum sp. nov., a new leaf spot pathogen of persimmon in Korea

Abstract

In this study, a new species within the genus Colletotrichum was isolated from diseased persimmon leaves collected from Sangju and Cheongdo in the Gyeongbuk province of Korea. The disease was characterized by leaf spots with a brown to gray center surrounded by a black ring with a green halo. Black acervuli with setae and numerous curved conidia were observed on the leaf spots. Phylogenetic analysis based on a combination of multiple loci, including sequences of the internal transcribed spacers, actin, beta-tubulin, chitin synthase-1, and glyceraldehyde-3-phosphate dehydrogenase genes, revealed that the isolates were clearly distinct from other species of the Colletotrichum dematium complex, with the closest species being C. anthrisci. Cultural and morphological characteristics and pathogenicity on persimmon leaves were examined. The isolates differed from C. anthrisci in their cultural and morphological characteristics, such as the conidia and appressoria. Based on molecular phylogenetic, morphological, and cultural characteristics and pathogenicity, this fungus was demonstrated to be a new species, Colletotrichum kakivorum, and the causal agent of a leaf spot disease on persimmon in Korea.