A new bacterial disease of maize (Zea mays) in the Eastern Mediterranean Region: bacterial stalk rot disease caused by Dickeya zeae

Aims: It is aimed to identify the bacterial pathogen that causes water soaking, browning, softening, rotting, unpleasant odour and collapses on stalks of maize plants growing in Adana and Osmaniye provinces in 2021 and 2022.Methods and Results: Plants showing bacterial stalk rot disease symptoms were collected from maize fields in Adana and Osmaniye provinces and 29 bacterial strains were obtained in the study. Totally 22 of the obtained strains caused soft rot on potato slices in pectolytic activity tests and showed positive results in pathogenicity tests on maize seedlings. Morphological, physiological and biochemical tests, MALDI-TOF and PCR tests were used to identify the strains and the strains were compatible with Dickeya zeae. The strains showed a high match with the CFBP-2052 coded Dickeya zeae isolate found in the MALDI TOF library with 2.264; 2.332; 2.339; 2.364 and 2.365 score values. In the PCR test using the ADE1/ADE2 primer pair, all of our strains were identified as Dickeya zeae by forming bands of 420 bp.Conclusions: In the study, the stalk rot disease caused by Dickeya zeae was observed for the first time in maize fields in Adana and Osmaniye provinces. Therefore, it is necessary to take precautions with cultural measures against the disease, which has no chemical control. So, the use of healthy and certified seeds, drip irrigation instead of wild or sprinkler irrigation, removal of all diseased plant residues from the fields, and increasing the microbial activity of the soil by beneficial microorganisms are important strategies in the management of the disease.Significance and Impact of the Study: Dickeya zeae causal agent of bacterial stalk rot disease of maize has been isolated and identified from diseased plants such as symptoms of water-soak appearance, browning, softening, rotting, unpleasant odour and collapse of the stalks in Adana and Osmaniye provinces.