Molecular Re-identification of Japanese Isolates of the Colletotrichum gloeosporioides Species Complex Associated with Grape Ripe Rot

Abstract

Ripe rot of grape caused by Colletotrichum spp. including the Colletotrichum gloeosporioides species complex (CGSC) is one of the important diseases in grape production. We re-identified seven grape strains deposited as CGSC in the NARO Genebank, Japan, based on the phylogenetic analysis with six loci (rDNA-ITS region, glyceraldehyde-3-phosphate dehydrogenase, actin, β-tubulin, calmodulin, and glutamine synthetase genes).These strains were isolated from five prefectures, i.e., Hokkaido, Yamanashi, Shimane, Hiroshima, and Fukuoka. Phylogenetic analysis based on these six loci revealed that one, three and three strains belonged to Colletotrichum siamense, Colletotrichum aenigma, and Colletotrichum viniferum, respectively. Leaves of potted grape plants were inoculated with three representative strains of three species. All inoculated plants exhibited leaf blight symptoms. Colletotrichum siamense, C. aenigma, and C. viniferum have not been reported as grape ripe rot pathogens in Japan, therefore; we propose these three species as the pathogens of the disease.