Detection of Soil-Borne Bacterial Diseases in Potato Cultivation in Niğde Province

Abstract

Potato is a globally important food crop, and Türkiye’s Niğde province has the largest potato cultivation area in the country. However, soil‑borne bacterial diseases including blackleg, soft rot, bacterial wilt, ring rot and common scab cause substantial yield and quality losses, and direct detection of these pathogens from field soils has been rarely performed. This study therefore aimed to isolate and characterize soil‑borne bacterial pathogens from potato production fields in Niğde. Soil samples were collected from symptomatic plant vicinities in Hasaköy, Alay and Altunhisar districts. Soil samples were serially diluted and inoculated onto the nutrient agar to isolate bacteria. A total of 27 morphologically distinct bacterial isolates were obtained. Pathogenicity of the isolates was determined using both a potato disc test and a tobacco hypersensitivity test. Among 21 isolates tested for pathogenicity, ten were positive in both the potato disc test and the tobacco hypersensitivity test. Genomic DNA was extracted from the ten isolates that were positive in both pathogenicity tests, and some of these were identified by 16S ribosomal RNA gene amplification and Sanger sequencing. BLAST analysis identified them as bacterial species belonging to genera commonly associated with potato diseases, including Streptomyces, which is known to cause common scab. The studies are still ongoing. These results demonstrate that diverse soil‑borne bacterial pathogens are present in Niğde’s potato production areas. Therefore, regular soil monitoring and integrated pest management are essential to reduce disease risks and sustain potato production in the region.