Molecular phylogenetic and pathogenetic characterization of Fusarium solani species complex (FSSC), the cause of dry rot on potato in Iran

• This is the first report on molecular identification of pathogenic Fusarium solani species complex strains isolated from potato tubers in Iran.
• In this research F. falciforme was reported for the first time in Iran.
• Potato tubers were found to be very susceptible to FSSC 5.

Members of Fusarium solani species complex (FSSC) are common pathogens of potato, causing dry rot in the west of Iran which involved Hamedan, Kermanshah, Eilam and Kurdistan provinces. Therefore, the objectives in this study were to isolate and identify disease-causing FSSC from infected potato tubers based on the morphological and molecular characteristics. Forty-five isolates of Fusarium were obtained from potato tubers collected from the wet market in different regions of the west of Iran and identified as FSSC through morphological characters. All of the isolates were evaluated for their pathogenicity on healthy potato tubers in the planthouse. The tubers rot symptoms were observed on the 21st day after inoculation of Fusarium isolates on the tubers tested. In the tubers inoculation tests, lesion sizes were quite variable; therefore, the measurement was done to compare the depth and width of lesion expansion among the isolates. Based on the sequence data from translation elongation factor (EF-lα) gene and internal transcript spacer (ITS) regions analysis, all of the selected FSSC isolates were divided into two major groups. This is the first report on molecular identification of FSSC strains isolated from potato tubers in Iran and Fusarium falciforme was reported for the first time in Iran.