Detection of resistance to Diaporthe toxica in asymptomatically infected lupin seedlings based on an immunoassay for phomopsin

An immunoassay for the detection of phomopsin was used to detect levels of the mycotoxin in epidermal peels from resistant and susceptible lupin cultivars asymptomatically infected with Diaporthe toxica. Quantifiable levels (> 6,25μg/kg) of phomopsin were detected in susceptible lupin cultivars, but not in very resistant breeding lines or in the control. These differences reflect the differences in resistance observed in microscopical assays and mature plants in the field.