Diversity and Distribution of Colletotrichum Species Causing Anthracnose in China

This study conducted a systematic investigation and identification of pathogenic fungi associated with anthracnose symptoms on economically important plants across multiple provinces in China (Beijing, Fujian, Guangdong, Guizhou, and Shaanxi). Through multi-locus phylogenetic analysis (ITS, gapdh, chs-1, act, tub2, his3, and cal) and morphological characterization of 67 strains, a total of 16 Colletotrichum species were identified, belonging to six species complexes (C. acutatum, C. boninense, C. destructivum, C. gloeosporioides, C. orchidearum, and C. spaethianum). Among these, four novel species were described: Colletotrichum aquilariae, C. crataegi, C. dongguanense, and C. flavosporum. The study also confirmed 12 known species: C. boninense, C. fioriniae, C. fructicola, C. godetiae (with C. americanum proposed as its synonym), C. gloeosporioides (with C. juglandicola, C. juglandium, and C. peakense proposed as its synonyms), C. karsti, C. nymphaeae, C. orchidearum (with C. subplurivorum proposed as its synonym), C. plurivorum, C. siamense, C. sojae, and C. spaethianum. The research revealed significant pathogen species diversity, distinct geographical distribution patterns (greatest diversity in Beijing, novel species primarily from Guangdong), and host preferences (e.g., C. gloeosporioides was the most widely distributed and dominant species on walnut). Furthermore, ten new host records were reported. The study explored correlations between pathogens and their hosts, particularly walnut, providing a crucial foundation for understanding the pathogen composition and ecology of anthracnose diseases affecting plants in China.