Isolation of pathogenic fungi causing postharvest decay in table grapes and in vivo biocontrol activity of selected yeasts against them

There is an increasing concern about the postharvest loss of table grapes due to pathogenic fungal decay. In order to identify the potential pathogenic fungi causing decay in table grapes at Zhenjiang, Jiangsu Province, China, we aimed to isolate fungi from decayed table grapes. Seven fungi, namely Aspergillus japonicas (A3), Aspergillus uvarum (B2), Cladosporium cladosporioides (C3), Aspergillus aculeatus (C4), Talaromyces rugulosus (C5), Penicillium georgiense (C7) and Penicillium expansum were isolated and identified as postharvest pathogens of grape berries. Among the isolated fungi, C. cladosporioides has the highest potential of disease-causing ability and pathogenic ability. To the best of our knowledge, this study represents the first isolation of P. georgiense from decayed grapes and confirmed its pathogenic potential in table grapes. In addition, the biocontrol ability of Saccharomyces cerevisiae, Rhodosporidium paludigenum, Rhodosporidium fluviale and Wickerhamomyces anomalus was examined against the isolated fungi. The yeast strains showed various levels biocontrol efficacy based on fungal strains. R. fluviale showed the highest biocontrol efficacy against all the isolated fungi. The present study will enrich the knowledge in postharvest fungal pathogens of table grapes as well as provides novel data in the field of biological control of postharvest decay of grapes.