Taxonomic and pathogenic characterization of species from West Azarbaijan, Iran, and description of two new species.

is a globally distributed genus, species of which occur in various ecological niches. Despite their importance as plant pathogens, information on species diversity and their distribution in West Azarbaijan Province of Iran is limited. This study aimed to investigate the taxonomy and plant pathogenicity of isolates recovered from soils in the province. A polyphasic taxonomy based on morphological, cultural, and multilocus sequence data revealed two new species, described here as and . In addition, a putatively new species and five known species, , and , were found in the studied region. , and were the three most frequent species isolated from soil, although was only found in one field. Among the studied species, , and exhibited various levels of pathogenicity on sugar beet, sunflower, and tomato, and was documented for first time as a plant pathogen. was highly aggressive on sugar beet and sunflower but lowly aggressive on tomato, whereas exhibited high aggressiveness toward the three crop plants. Both and were found to be lowly aggressive on the host plants. The results indicated that members of , particularly plant-pathogenic species, are common in arable soils of West Azarbaijan Province and can pose a threat to agricultural crops in the region.