Root rot alters rhizosphere fungal community and suppresses soil enzyme activities in Lily

To clarify the pathogenesis of lily root rot, we compared the rhizosphere fungal community and soil enzyme activities of healthy and diseased Lilium brownii var. viridulum plants from a six-year continuous monoculture field. Urease, sucrase, and acid phosphatase activities were significantly suppressed in diseased rhizosphere. High-throughput ITS sequencing revealed a drastic reduction in fungal richness (Chao1) and a shift in community structure. Ascomycota relative abundance surged, while Basidiomycota and Zygomycota declined sharply. Pathogenic genera (Fusarium, Gibberella, Neonectria, etc.) were significantly enriched, whereas several potentially beneficial genera (Mortierella, Trichoderma, Cladorrhinum, etc.) were depleted. These findings characterize the microecological imbalance underlying lily root rot and provide a foundation for future biocontrol strategies.