Quantitative and qualitative analysis of Botrytis inoculated on table grapes by qPCR and antibodies

The fungus Botrytis cinerea is the major cause of decay in table grapes during storage, and the severity of decay depends in part on contamination with the fungus before storage. The current SO2 technology to prevent decay is robust and independent of the level of contamination by B. cinerea. The introduction of alternative technologies may however require implementation of means which are proportional to the level of contamination. The objectives of this study were to test the feasibility of quantifying B. cinerea in artificially inoculated grapes and to monitor the progress of disease during storage. Two methods were compared for detection of B. cinerea in grapes; an antibody kit specific for B. cinerea, and quantitative PCR using fungal specific primers. Antibodies for fast detection of B. cinerea yielded positive results only in the later stages of decay development. In contrast, the quantitative PCR demonstrated positive identification of the fungus at all storage time points, and found increasing amounts of the fungus during storage.