Identification and Characterization of Causing Southern Blight on in Northeast China.

is a perennial medicinal plant that belongs to the Ranunculaceae family and is distributed mainly in Northeast and North China. In July 2018, a typical southern blight disease of was observed in commercial fields of Qingyuan County, Fushun City, Liaoning Province, China. The fungus mainly infected stem base and tuberous roots of the plant by wrapping the hyphae and absorbing nutrition, resulting in tuberous root wilted or whole plant death. Morphological characteristics of colony and sclerotia of three representative strains isolated from the diseased plants differed from those of isolated from . Sclerotia were large (0.8 to 5.1 mm), reddish-brown, and irregular and had pitted surfaces, and the hyphae were white, compact, or fluffy, with a growth rate ranging from 8.0 to 10.1 mm/day. Phylogenetic analysis of the internal transcribed spacer and the large subunit sequences of Akln6, Akln9, and Akln15 showed that three strains isolated from formed a unique and well-supported clade that groups with the reference isolates of . Based on phylogenetic analysis and cultural and morphological characteristics, the three isolates of were identified as The optimum temperature for mycelial growth of the three tested isolates was 30°C, and sclerotia formed and matured more easily at 20°C. Light promoted the growth of mycelial, whereas dark was beneficial to the formation and maturation of sclerotia. The pathogenicity of showed stronger than at low temperature (20°C). This is the first report of causing southern blight on in China, and this finding provides a basis for disease-accurate diagnosis and the development of effective management strategies.