Development of novel specific primers for rapid detection and identification of Dickeya zeae by classic PCR

Plant pathogenic bacterium Dickeya zeae is causing severe economic losses to many cultivated plants worldwide. Wide host range and high aggressiveness of D. zeae causes significant problems for the pathogen identification at the early stage of disease and in the choice of appropriate control methods. A rapid and accurate detection and identification of D. zeae in seeds, planting material, and in the field is needed to reduce potential yield losses. This study was aimed to develop simple and reliable PCR assay for identification of D. zeae suitable for pure culture and for plant material. Two primer pairs (DZRA-F/DZRA-R and rpoZeae-F/rpoZeae-R2M) were targeted on the sequence of D. zeae genes recA and rpoD. These primers amplified the target DNA fragments in D. zeae, but not in other Dickeya spp. and in 26 bacterial strains of other genera. The DZRA-F/DZRA-R and rpoZeae-F/rpoZeae-R2M have detected D. zeae at the lowest level of 10 DNA copies (DZRA-F/DZRA-R) or 50 DNA copies (rpoZeae-F/rpoZeae-R2M) per reaction. These primers were capable of detecting the presence of D. zeae in diseased plants and were more sensitive than conventional Dickeya spp.-specific primers ADE1/ADE2. PCR assay based on DZRA-F/DZRA-R or rpoZeae-F/rpoZeae-R2M, and ADE1/ADE2 primers can be used as a powerful tool to identify D. zeae in pure culture or diseased plants. © The Author(s), under exclusive license to Sociedade Brasileira de Fitopatologia 2026.