New records of Penicillium and Aspergillus from withered grapes in Italy, and description of Penicillium fructuariae-cellae sp. nov.

Abstract

Penicillium and Aspergillus are common pathogenic fungi of grapes, that occur frequently on withered berries used in the Italian passito wine production. Members of these genera isolated from withered grapes were identified using molecular and morphological approaches. The isolates were examined by amplification of internal transcribed spacer region, β-tubulin, calmodulin and RNA polymerase II second largest subunit. Penicillium bilaiae, Aspergillus pallidofulvus and A. puulaauensis are reported for the first time from Vitis vinifera. Two Penicillium isolates showed a distinct phylogenetic position and different morphological characteristics from P. bissettii and P. vasconiae, the two most closely related species. These isolates are assigned to the new species Penicillium fructuariae-cellae, that is here described. An in vitro pathogenicity assay was carried out to evaluate the infectivity to grape berries by Penicillium and Aspergillus isolates recovered in this study. All examined isolates colonized the berries when artificially inoculated, but to a lesser extent than Botrytis cinerea. This suggests that these fungi may contribute, with other pathogenic species, to the onset of post-harvest diseases of grapes.