Plant pathogenic pectolytic bacteria in the mycelia of the fungi infecting potato tubers

Fungi are closely associated with bacteria. The fungus helps the bacteria to survive in severe conditions and can promote their spread with growing fungal hyphae. Three strains of the pectolytic bacteria were isolated from the mycelium of plant pathogenic fungi Fusarium torulosum and Trichocladium solani. Pure fungal cultures were obtained from the potato tubers with dry rot symptoms of the Geyser potato variety grown in the Kamchatka Territory (Far East, Russia). All analysed bacterial strains infected potato tuber’s slices at temperatures + 10 °C and + 25 °C. The lesions looked almost the same after 24 h at both incubation temperatures. Sequences of gene regions 16S rRNA, gyrase B (gyrB) and RNA polymerase sigma factor (rpoD) of the tested bacteria were identical to those of Pseudomonas palleroniana. The presence of plant pathogenic bacteria in the fungal mycelia should be considered when developing plant protection systems. © The Author(s) under exclusive licence to Società Italiana di Patologia Vegetale (S.I.Pa.V.) 2025.