<i>Clarireedia japonici</i> , a new fungal species causing dollar spot disease of creeping bentgrass in Japan

Abstract Clarireedia spp. are known as the fungal pathogen causing dollar spot disease in turfgrasses. We already reported Clarireedia jacksonii on cool‐season grasses and Clarireedia monteithiana on warm‐season grasses in Japan. But the fungal group TG1 could not belonged to any known species of Clarireedia . In results of checking the nucleotide sequences of ribosomal DNA internal transcribed spacer (rDNA‐ITS), elongation factor‐1α ( EF1α ) gene, and mini‐chromosome maintenance protein ( MCM7 ) gene, two strains, B10 and B11, belonging to the group TG1 were concluded to be a new Clarireedia species based on morphological characteristics and molecular phylogeny, and we named it Clarireedia japonici n. sp. The species was isolated from creeping bentgrass and has been found only in Shizuoka and Kyoto Prefectures, in central Japan. Since we have already reported the strain B10 showed strong pathogenicity in bentgrass, but not so strong in zoysiagrass, C. japonici was estimated to be virulent to bentgrass, the cool‐season grass like C. jacksonii that was most closely related in the molecular phylogeny.