Characterization of Diplodia seriata and Neofusicoccum parvum associated with grapevine decline in Iran

During 2004-2007, a field survey was conducted in different vineyards to determine the fungal pathogens associated with grapevine decline in different provinces of Iran including Fars, Hamedan, Isfahan, and Kohgiluyeh and Boirahmad. Twenty-seven isolates of Botryosphaeriaceae were recovered from vines showing decline and dieback symptoms only in Fars Province. Based on morphological and cultural characters along with molecular analysis [partial sequences of the nuclear ribosomal internal transcribed spacer (ITS), beta-tubulin (BT), and elongation factor 1-α (EF)], two species of Botryosphaeriaceae, namely, Diplodia seriata and Neofusicoccum parvum were identified. Both species were pathogenic on rooted cuttings of cv. Cabernet Sauvignon and caused the dieback and drying-out of leaves as well as extended lesions on the shoots 4 months after inoculation. Results showed that N. parvum isolates were the most virulent and produced significantly longer lesions than those caused by D. seriata. Both species were reisolated from the margin of the lesions completing Koch’s postulates