Browning in pure white Auricularia cornea ‘Yumuer’: identification and control management of conditional bacterial disease induced by Pseudomonas canadensis

BACKGROUND: Auricularia cornea 'Yumuer' is a highly nutritious and economically valuable mushroom crop, widely favored by consumers. However, bacterial browning disease poses a significant threat to its yield and quality. This study aimed to identify the causal agent of browning, clarify its environmental determinants, and evaluate effective chemical control measures. RESULTS: This study reports a novel bacterial disease affecting wood ear mushrooms. The pathogenic strain DB1028 was isolated from the browning tissues of symptomatic fruiting bodies, and its pathogenicity was confirmed by fulfilling Koch's postulates. Morphological characteristics, physiological and biochemical properties, and multi-locus phylogenetic analyses identified the pathogen as Pseudomonas canadensis Epidemics were driven by high temperature (greater than 28 °C) and humidity (greater than 90%), causing 100% incidence rate and a severe disease index. Among the tested antibiotics, streptomycin exhibited high efficacy with a minimum inhibitory concentration of 4.53 μg/mL, indicating its potential for safe and effective control. CONCLUSION: This study is the first to definitively identify the causal agent of bacterial browning disease in Auricularia cornea 'Yumuer', elucidate its environmentally dependent pathogenic pattern, and propose effective chemical control strategies. These findings provide a theoretical foundation and offer novel insights for the prevention and management of bacterial diseases in gelatinous edible fungi. © 2025 Society of Chemical Industry.