Identification of the Fungal Agents Associated with Almond Trunk Diseases in East Azerbeijan Province

Trunk diseases are among the important diseases of almond trees, considered as a potential threat for the almond cultivation and production. Given the incidence of the trunk diseases on almond trees in the orchards of East Azarbaijan province, the identity of fungal species associated with disease symptoms mainly remain unknown. In this study, the fungal species associated with the trunk diseases on almond trees in East Azerbaijan province were characterized using morphological and molecular data. A total number of 115 fungal isolates were recovered from diseased samples showing canker and wood decay and discoloration symptoms. The identity of the fungal species were determined by using both morphological and sequence data of the ITS-rDNA region. The results revealed Collophora hispanica as the dominant species amongst the fungal groups associated with almond trunk diseases in this region with the isolation frequency of 61.73 percent. In addition fungal species including Cytospora chrysosperma, Truncatella angustata, Beauveria bassiana, Acrostalagmus luteoalbus, Quambalaria sp., Clonostachys rosea, Fusarium proliferatum, F. acuminatum, F. torulosum, F. solani, F. avenaceum, F. oxysporum, Paecilomyces variotii, Trichothecium roseum, Phellinus sp. and Phoma sp. were isolated with lower frequencies. All of the species, except, C. chrysosperma, P. variotii, C. rosea, T. roseum and Phellinus sp. represent new records on almond for Iran. Additinaly, T. angustata, F. torulosum, F. proliferatum and Quambalaria sp. are newly reported on almond all over the world. With the identification of fungal species associated with almond tree decline in this region it will be possible to evaluate their pathogenicity on almond and eventually practice suitable management strategies for this complex disease.