Pathogenicity of some Fusarium species associated with superficial blemishes of potato tubers.

As an organ for reserve and propagation, the tuber grows underground and is in contact with soil-borne microorganisms, making it potentially exposed to blemishes. Therefore, the objective of this study was the possibility of using some modern methods of molecular diagnostics and detection of the presence of fungal contaminants in potato blemishes in Al-Qasim (Saudi Arabia). Polygonal lesions were the most observed blemish type in the collected samples. One hundred and sixty isolates were recovered from different types of blemishes obtained in this study. Fusarium, Penicillium, Ilyonectria, Alternaria and Rhizoctonia were the most common genera collected from different blemish types. Using ITS region sequencing, all collected fungi were identified at the species level. All Fusarium strains collected during this study were used to detect their pathogenicity against potato tubers. This is the first comprehensive report on the identification of major pathogenic fungi isolated from potato tuber blemishes in Saudi Arabia.