Molecular identification of Fusarium species causing dry rot disease in potato fields in Afyonkarahisar province

Potato plant (Solanum tuberosum L.), which has significant place in human nutrition belongs to the family of Solanaceae. Although potato originated in South America, it is grown all over the world due to its high adaptibility and productivity. The province of Afyonkarahisar ranks third after Niğde and Konya in terms of total potato production in Turkey. Dry rot disease caused by the species of Fusarium after harvest and in storage is one of the most important fungal diseases of potato tuber. In this study, it is aimed to detect and identify as well as to determine distribution of Fusarium species resposible for dry rot disease in Afyonkarahisar province which is one of the signifcant potato production areas of the country. For this purpose, potato tubers displaying dry rot symptoms were collected from Sandıklı, Şuhut, Dinar, Center and Bolvadin districts and the isolations of the fungus were carried out from the samples. Internal Transcribed Spacer (ITS) and Elongatin Factor (EF) gene regions of 32 Fusarium isolates recovered from the tubers with dry rot symptoms were amplified respectively with ITS1/ITS4 and EF1/EF2 primers in Polymerase Chain Reaction (PCR) assays and the DNA sequences of the isolates were obtained. The sequences of ITS and EF regions of the isolates were compared with the isolates in the Gen bank in NCBI BLAST analysis and phlogenetic analysis to identify and caharacterize the species of the fungus common in the storage areas of Afyonkarahisar province. Of total 32 isolates from 5 districts of Afyonkarahisar province, 15 Fusarium oxysporum (%47),8 Fusarium solani(%25), 5Fusarium sambucinum(%16) and 4 Fusarium graminearum (%13) species were identified and characterized in both DNA sequence and phlogenetic analysis. The DNA sequences of ITS and EF regions of the isolates were found to be highly compatible with each other and to separate the Fusarium species with high accuracy. Phylogenetic analysis of the DNA sequences of the both region further confirmed that Afyonkarahisar isolates were consist of 4 species that are completely different from each other. The analysis also showed that the isolates of F. sambucinum and F. graminearum were different but closely related two species. The results of EF gene region phylogenetic analysis also indicated the isolates comprised of 4 different Fusarium species and the presence of two completely different groups of Fusarium oxysporum isolates in the region. First time, the species of Fusarium were identified and characterized by molecular methods as the causal agents of dry rot disease in the storage facilities of Afyon province in this study.