Fusarium acutatum همراه با پوسیدگی غده و ریشه سیب زمینی در استان کرمان

Potato (Solanum tubersum L.) is one of the important and basic agricultural crops which plays an important role in human nutrition in different countries. Some soil-borne fungi, including Fusarium species, are known as the most common fungal pathogens. During a survey conducted in the major potato-growing areas in Kerman Province, disease symptoms include of yellowing, root and tuber rot were observed in some potato fields in Jiroft county. In order to identify the fungi associated with these symptoms, samples were collected from the diseased plants and transferred to the laboratory. Symptomatic plant tissues from infected roots and tubers were cut (3-5 mm) and surface-sterilized with a 5% solution of sodium hypochlorite (NaClO) for 60 s and then washed twice with sterile distilled water. Tissue pieces were dried on sterilised filter paper under the laminar hood, and then plated onto potato dextrose agar (PDA) plates. Petri plates were incubated in the dark at 25 °C and the emerged fungal colonies were transferred to new PDA Petri dishes. In this study, 10 isolates of a Fusarium sp. were isolated from infected potato tissues. The isolates were identified based on morphological and molecular characteristics. The genomic DNA of two representative isolates was extracted using CTAB method and the internal transcribed spacer (ITS) region and a partial of nuclear translation elongation factor 1-alpha (tef-1α) were amplified using the primers ITS1/ITS4 and EF1-728F /EF1-986R, respectively. Based on the characteristics of the culture medium, microscopic structures and molecular analysis, the representative isolates were identified as Fusarium acutatum. The results of the pathogenicity tests showed that this species is capable of causing tuber and root rot symptoms on inoculated potato plants. Based on the review of previous references, this study is the first report of this species on potato.