New species of Phaeomoniellales from a German vineyard and their potential threat to grapevine (Vitis vinifera) health.

Abstract

Recently, the order Phaeomoniellales was established that includes fungi closely related to Phaeomoniella chlamydospora, a phytopathogen assumed to be the main causal agent of the two most destructive grapevine trunk diseases, Petri disease and esca. Other species of this order are reported as pathogens of other economically important crops, like olive, peach, apricot, cherry, plum, rambutan, lichee or langsat. However, they are rarely isolated and hence, little is known about their ecological traits and pathogenicity. During a 1-yr period of spore trapping in a German vineyard divided in minimally and intensively pruned grapevines, 23 fungal strains of the Phaeomoniellales were collected. Based on morphological and molecular (ITS, LSU and tub2) analyses the isolated strains were assigned to eight different species. Two species were identified as P. chlamydospora and Neophaeomoniella zymoides, respectively. The remaining six species displayed morphological and molecular differences to known species of the Phaeomoniellales and are newly described, namely Aequabiliella palatina, Minutiella simplex, Moristroma germanicum, Mo. palatinum, Neophaeomoniella constricta and N. ossiformis. A pathogenicity test conducted in the greenhouse revealed that except for P. chlamydospora, none of the species of the Phaeomoniellales isolated from spore traps is able to induce lesions in grapevine wood.