First report of Colletotrichum acutatum sensu lato (Colletotrichum godetiae) causing anthracnose on grapevine (Vitis vinifera) in the United Kingdom

In November 2009, twelve specimens of grapevine (Vitis vinifera) cv. Brant in the area of Penrith, Cumbria in the United Kingdom were showing necrotic black leaf spotting and abundant orange sporulation on the upper leaf surface. Infected plant material was submitted to the FERA (Food and Environment Research Agency) Plant Clinic for diagnosis. The tissue samples were surface sterilised for one minute in 20% sodium hypochlorite and cultured on potato dextrose agar. Monoconidial isolates grown at 25°C with a 12 hour light period had light grey cottony aerial mycelium with colour ranging from whitish to dark grey on the reverse side of the colony. The cultures had orange spores organised in small masses and dark melanised structures similar to acervuli. Disease symptoms and morphology suggested that a member of the genus Colletotrichum caused the disease. Given the fact that strains of Colletotrichum often belong to aggregates of species that can be difficult or impossible to distinguish morphologically, a representative isolate was sent to the University of Warwick for further analysis.