Fungal pathogens associated with grapevine trunk diseases in Iran

Resumen

During 2004-2007 various own rooted vineyards were inspected to study the fungi associated with vine trunk diseases in Iran. Samples from declining vines showing yellowing and reduced growth and different symptoms in wood, including browning of the wood, necrosis, brown and black streaking and white rot were collected. Fungal isolations were made from affected tissues onto Malt Extract Agar (MEA) supplemented with 1 g l-1 streptomycin sulphate (MEAS). Based on morphological and molecular characteristics, the following species were identified: Phaeoacremonium (Pm.) aleophilum, Phaeomoniella (Pa.) chlamydospora and less frequently Pm. parasiticum, Pm. inflatipes, Pm. cinereum, Cylindrocarpon liriodendri, Diplodia seriata and Neofusicoccum parvum. Results of the pathogenicity tests under field conditions showed that Pa. chlamydospora and Phaeoacremonium spp. caused large wood discoloration 10 months after inoculation without any external foliar symptoms. Phaeomoniella chlamydospora caused larger lesions than Phaeoacremonium spp. All inoculated species were re-isolated from the margin of the lesions completing Koch's postulates. This study represents the first comprehensive work that investigates the molecular and morphological identification and pathogenicity of Phaeoacremonium spp. and Pa. chlamydospora associated with vine decline in Iran. This is also the first report of Pm. inflatipes, N. parvum and D. seriata associated with grapevine decline in this country.