Genetic Diversity of Colletotrichum spp. Causing Grape Anthracnose in Zhejiang, China

Anthracnose is a fungal disease that seriously threatens grape production and quality. Multiple Colletotrichum species are detected in anthracnose grapes in vineyards. In this study, diseased grapes were collected in four counties in Zhejiang, and 43 Colletotrichum isolates were obtained. Multi-genes (ITS, TUB2, ACT, CHS-I, and GAPDH) and morphological characteristic analyses showed that C. fructicola (40 isolates, 93%), C. aenigma (two isolates, 4.7%), and C. pseudoacutatum (one isolate, 2.3%) were the cause of grape anthracnose in Zhejiang. Among the three Colletotrichum species, C. fructicola was the prevalent and dominant species in all sampled counties; C. pseudoacutatum was first identified as the pathogen responsible for grape anthracnose. There were significant differences in the sporulation among the three Colletotrichum species, as well as in the spore germination. Pathogenicity testing showed that all species can infect grapes, resulting in anthracnose. On the other hand, the virulence of species was varied and may be associated with their spore germination. This is the first study to characterize the Colletotrichum species causing grape anthracnose in Zhejiang Province and reveal that C. fructicola is the dominant species. The determination of Colletotrichum species associated with grape anthracnose may contribute to the study of epidemiology and development of an efficient strategy for controlling anthracnose in the vineyards.