Clarireedia hainanense: A New Species Is Associated with Dollar Spot of Turfgrass in Hainan, China

The genus Clarireedia contains multiple species causing dollar spot (DS) on turfgrass worldwide. In November 2020, 119 Clarireedia isolates were obtained from symptomatic seashore paspalum at golf courses in Hainan province and identified to species level based on partial sequence of the internal transcribed spacer (ITS) region. A total of 45 and 22 isolates were identified as C. paspali and C. monteithiana, respectively; the remaining 52 isolates defined a new clade. Isolates from this clade were further selected for phylogenetic, morphological, and biological analyses. Maximum likelihood and Bayesian methods were implemented to obtain phylogenetic trees for partial sequences of the ITS, EF-1α, and McM7 genes. The selected isolates consistently fell into a distinct, well-supported clade within Clarireedia. Morphological and biological characteristics were observed among the different species in Clarireedia. Altogether, this study described a new species, Clarireedia hainanense, which has widespread distribution in Hainan, China. These findings may have important implications for the management of DS disease.