Determination of Bacterial Contamination in Orange and Black Carrot Seeds

Carrot (Daucus carota L.) is one of the top-ten most economically important vegetables crops in the world. Turkey is one of the world's most important carrot producers with its annual production of 300,000 to 400,000 tons. Seed-borne bacterial pathogens of carrot cause important damage on yield and seed quality on plants. In this study, infested bacteria were determined on some carrot seeds sown in Turkey. Different orange and black varieties of carrot seeds were collected from the Eregli and Kasınhanı districts of Konya province, Turkey's largest carrot-producing regions. Subsamples of 10,000 seeds were soaked overnight at 5 °C in 100 mL sterile saline (0.85% NaCl) with 0.02% Tween 20. A ten-fold dilution series was prepared from each seed soak extract and 100 μL of each dilution and the undiluted extract were spread in triplicate on yeast dextrose calcium carbonate agar (YDCA), Kings B medium (KB), tryptic soy agar (TSA). Morphological, biochemical, physiological, and molecular methods were used for identification of isolated bacteria. Pathogenicity tests of strains were performed on black and orange carrots, and all strains induced a hypersensitive response in tobacco plants. Obtaining pathogenic and beneficial bacteria strains were identified from Pseudomonaceae, Bacillaceae, and Enterobacteriaceae families. It is important to determine the level of disease incidence in fields and alert the farmers to apply quarantine regulations. The next stage of this study will be to determine their agronomic importance on carrot production in Turkey.