Alternaria telliensis, a new causal agent of cabbage leaf spot disease in Iran

In order to study of cabbage leaf spot disease in Damavand region, Tehran province, Iran, symptomatic cabbage leaves (Brassica oleracea var. capitata) were collected during the late summer and fall of 2017. Twenty-one isolates with the main characteristics of the genus Alternaria were isolated from lesions on the cabbage leaves. Based on morphological characteristics and phylogenetic analysis using multi-gene sequences, they were identified as Alternaria telliensis. Pathogenicity tests were conducted on cabbage leaves under greenhouse conditions and characteristic lesions were formed on inoculated leaves. Re-isolation of the inoculated fungus from the treated leaves confirmed Koch’s postulates. Based on the available information, this is the first occurrence of A. telliensis as a new species and pathogen to cabbage plants in Iran.