Identification of Pestalotiopsis bicilita, Diplodia seriata and Diaporthe eres causing fruit rot in withered grapes in Italy

Pestalotiopsis biciliata, Diplodia seriata and Diaporthe eres were recovered from severely diseased bunches of withered grapes for Amarone wine production. To our knowledge this post-harvest disease has never been seen before in withered grapes. Fruit rot occurred with bunches containing decayed berries partially or totally covered by whitish mycelium. Morphological and phylogenetic analyses of fungal isolates from symptomatic fruits enabled species delimitation. Pathogenicity tests revealed that the three species are able to infect grape berries confirming that they are casual agents of fruit rot. This study provides preliminary insights on this post-harvest disease that might have important implications in grape quality.