Morphological and molecular characterisation of Diaporthe species associated with grapevine trunk disease in China

Trunk diseases in grapevine (Vitis spp.) are major problems in the wine and table-grape industries reducing the productivity, quality and longevity of vineyards. Species of Diaporthe are important fungal pathogens of grapevine trunk disease worldwide. A survey of 14 grape vineyards located in different provinces of China was yielded Diaporthe isolates associated with symptomatic grapevine wood. These isolates were identified based on morphology and a combined data matrix of rDNA ITS, partial sequences of translation elongation factor 1-α (EF 1-α), β-tubulin (TUB) and calmodulin (CAL) gene regions. Four species of Diaporthe were identified, which included Diaporthe eres, Diaporthe hongkongensis, Diaporthe phaseolorum and Diaporthe sojae. All isolates of Diaporthe caused disease on detached grape shoots in pathogenicity experiments but differed in virulence. The incidence in local vineyards and the pathogenicity results indicate that D. eres is an important pathogen of grapevine in Chinese vineyards, where it may significantly limit grape production. This is the first detailed report of Diaporthe species associated with grapevine trunk diseases in China with morphology, pathogenicity and molecular data.