In Mediterranean climates (e.g., California), foliar symptoms are less common, but D. ampelina and other Diaporthe species are instead more frequently associated with the formation of wood cankers (Lawrence et al. 2015), Phomopsis dieback being part of the grapevine trunk-disease complex (Úrbez-Torres et al. 2013). In controlled experiments, grapevine cultivars responded differently to wood infection by D. ampelina (Travadon et al. 2013), suggesting a genetic component in the plant–pathogen interaction. To date, the genetic and molecular bases of Phomopsis resistance in grapevines have not been reported.