Identification of the causal agents of crazy root disease on hydroponically cultivated cucumber plants in Poland

Abstract In April 2019, hydroponically cultivated cucumber plants with characteristic symptoms of crazy root disease were found in two different commercial production greenhouses Poland. Due to excessive and inappropriate growth, this led a reduction yield deterioration the general conditions infected plants. Bacteria isolated from roots subjected morphological evaluation, as well molecular, biochemical pathogenicity tests. To identify bacteria causing disease, Agrobacterium -like colonies PCR primers complementary pathogenicity-related genes located on root-inducing plasmid (Ri-plasmid): virD2A + virD2E virD2 gene rolBF rolBR rolB gene. The strains was studied sunflowers cucumbers. Twelve positive for Ri plasmid, determined by PCR, pathogenic identified based sequence analysis 16S rRNA recA genes. One strain classified belonging genus Pararhizobium , three Rhizobium eight biovar 1, highest similarity genomospecies G3. results analyses suggest that these may belong new, thus far, undescribed species. confirm hypothesis, further phylogenetic studies are required.