عنوان مقاله [English]
نویسندگان [English]چکیده [English]
During the study on the Alternaria species from potato fields of West Azerbaijan province, foliage and stems that had suspected infections with Alternaria fungi were collected. Totally, 141 isolates belonging to the genus Alternaria were isolated and purified. Based on macro and micomorphological characters of the isolates, 9 species viz.: A. alternata, A. broussonetiae, A. destruens, A. dumosa, A. interrupta, A. rhadina, A. solani, A. soliaegyptiacae and A. tenuissima were identified. Among the identified species, 5 species: A. alternata, A. dumosa, A. interrupta, A. solani and A. tenuissima were reported previously from potato, but three species: A. broussonetiae, A. rhadina and A. soliaegyptiaca are new to mycoflora of Iran and are reported for the first time from potato plants (matrix nova). Also, potato is matrix nova for A. destruens. Pathogenicity studies on isolates of identified species were done on potato cultivar Agria and their pathogenicity were confirmed based on Koch´s postulates. All the studied isolates were pathogenic, although the degree of pathogenicity based on diameter of necrotic area varied among different species. A. tenuissima had the highest frequency and A. solani and A. tenuissima had the highest degree of pathogenicityamong the studied Alternaria isolates.