Fig. 1

Symptoms of natural infection of brown blotch disease in A. bisporus, pathogenicity testing, and phylogenetic analysis of the pathogens. a Symptoms of natural infection in young fruiting bodies. b Symptoms of natural infection in mature fruiting bodies. c Symptoms 48 h after inoculation with P. tolaasii suspension. d Pathogenic symptoms in pot experiments with inoculation of 1 × 10⁸ CFU/g (soil wet weight) P. tolaasii. e Symptoms 48 h after inoculation with C. neteri suspension. f Pathogenic symptoms in pot experiments with inoculation of 1 × 10⁸ CFU/g (soil wet weight) C. neteri. g Phylogenetic tree of inter-species relationships within the Pseudomonas genus, based on concatenated sequences of 16S rRNA (1–1334 bp), gapA (1335–1904 bp), gltA (1905–2648 bp), gyrB (2649–3085 bp), recA (3086–3781 bp), and rpoB (3782–4479 bp). h Phylogenetic tree of C. neteri and closely related species based on concatenated sequences of 16S rRNA (1–1195 bp), atpD (1196–2080 bp), dnaJ (2081–2700 bp), tuf (2701–3033 bp), and gyrB (3034–4173 bp). The tree was constructed using the Maximum Likelihood method (ML). ▲ indicates strains isolated in this study