Characterization of Phaeoacremonium isolates associated with Petri disease of table grape in Northeastern Brazil, with description of Phaeoacremonium nordesticola sp. nov.

Abstract

This study aims to identify and characterize species of Phaeoacremonium associated with Petri disease of table grapes in three regions in the Northeastern Brazil, to investigate the distribution of the species in these regions and to evaluate their pathogenicity and aggressiveness in excised green shoots of table grapes. Fungal identifications were made using a combination of morphology together with a phylogenetic analysis based on portions of the β-tubulin (TUB2) and actin (ACT) genes. Three species of Phaeoacremonium (Pm.) were identified: Pm. minimum, Pm. nordesticola sp. nov. and Pm. parasiticum. Phaeoacremonium minimum and Pm. parasiticum had previously been reported in grapevine. Phaeoacremonium minimum was the most prevalent species. All species of Phaeoacremonium were pathogenic on detached shoots of table grape, with Pm. minimum being the most aggressive.