Abstract:[Objective]This study aims to understand the potential harmful fungi that may affect the quality of raisins during the drying process of grapes from Turpan, Xinjiang and to explore the relationships between varieties and the fungal community structure and diversity on the surfaces of grapes and raisins.[Method]Four popular grape varieties (‘Thompson Seedless’, ‘Boerte’, ‘Xiangfei’, and ‘Seedless Black’) in a grapery in Turpan were selected as research objects. The fungal diversity on the surfaces of grapes and raisins was analyzed via high-throughput sequencing.[Result]The dominant fungal phyla on the surfaces of grapes and raisins were Ascomycota and Basidiomycota. The average relative abundance of Ascomycota on the surfaces of raisins (92.24%) was higher than that on the surfaces of grapes (81.43%), while Basidiomycota had higher average relative abundance on the surfaces of fresh grapes (9.35%) than that on the surfaces of raisins (2.44%). At the genus level, the dominant fungal genera on the surfaces of grapes were Aspergillus, Cladosporium, Alternaria, and Hanseniaspora. The average relative abundance of Aspergillus on the surfaces of raisins (61.75%) was higher than that on the surfaces of grapes (43.97%), while the average relative abundance of Cladosporium on the surfaces of grapes (8.61%) was higher than that on the surfaces of raisins (5.76%). Additionally, dominant fungal species such as Aspergillus carbonarius, Cladosporium cladosporioides, and Aspergillus versicolor were identified.[Conclusion]At various taxonomic annotation levels of species, the surfaces of grapes and raisins may harbor pathogenic fungi such as Aspergillus carbonarius, Cladosporium cladosporioides, Aspergillus versicolor, and unclassified taxa which potentially produce mycotoxins. These fungi varied between grapes and raisins at different taxonomic levels. Pathogenic fungi were present before and after grape drying with no significant change, indicating their persistence throughout the drying process.
