Two new species of Colletotrichum (Glomerellales, Glomerellaceae) causing anthracnose on Epimediumsagittatum.

Epimediumsagittatum (Sieb. et Zucc.) Maxim, a perennial herb belonging to the Berberidaceae family, is widely used in traditional Chinese medicine for its beneficial role in enhancing kidney function, strengthening bones and muscles, and dispelling wind-dampness. Clinically, it is commonly used to treat osteoporosis, rheumatism, hypertension, and cardiovascular diseases. During 2023 to 2024, a disease suspected to be anthracnose was observed to be infecting the bases of Epimedium seedlings in Bibo Town, Kaili City, Guizhou Province. In the fall, the disease incidence reached 90%, with severe infection resulting in total desiccation and foliage death. Tissue isolation and single-conidium methods were used to identify and isolate the pathogens, which were determined to be two anthracnose strains. Multi-locus phylogenetic analysis using ITS, gapdh, act, tub2, chs-1, his3, and cal, and morphological observations of representative isolates indicated that the two isolated fungal strains were new species belonging to the genus Colletotrichum, namely Colletotrichumepimedii and Colletotrichumsagittati. Pathogenicity tests, adhering to Koch's postulates, confirmed that both fungi could infect E.sagittatum; C.epimedii exhibited a higher pathogenicity than C.sagittati. The present study provides valuable information regarding the prevention of E.sagittatum anthracnose.