白芍根腐病病株与健株根际土壤微生物群落及酶活性变化.

[Objective] Analyzing the changes of microbial community and enzyme activities in the rhizospheric soil of Paeonia lactiflora with root rot and understanding the relationship between soil environmental factors, microbial community and root rot of P. lactiflora would provide the scientific basis for controlling root rot of P. lactiflora. [Method] Illumina high throughput sequencing technology and soil physicochemical property method were employed to investigate soil bacterial and fungal communities, soil nutrients and enzyme activities of rhizosphere soil of healthy and root rot diseased plants of P. lactiflora. [Result] The content of soil organic matter in the rhizosphere of diseased plants significantly increased, the content of available potassium significantly decreased, and the content of soil alkaline phosphatase and peroxidase significantly increased, compared with healthy plants of P. lactiflora. The richness and diversity of bacteria decreased, but the richness and diversity of fungi increased in the rhizosphere soil of root rot diseased plants of P. lactiflora. The relative abundance of Proteobacteria, Bacteroidota and Sumerlaeota in the rhizosphere soil of root rot diseased plants of P. lactiflora was significantly higher than that of healthy plants, but Chloroflexi, Actinobaciota, Ethylomirabilota and Firmicutes decreased significantly. Sphingomonas, Chtoniobacter, Subgroup7 and Saccharimondales in the rhizosphere soil of root rot diseased plants of P. lactiflora was higher than that of healthy plants. The relative abundance of Ascomycota increased and Basidiomycota decreased in the rhizosphere soil of root rot diseased plants of P. lactiflora, and Zygomycota was significantly higher than that of healthy plants. The pH, organic matter, available phosphorus, available potassium, water-soluble salt, alkaline phosphatase, peroxidase, urease and sucrase were important factors that affected the changes of microbial community in the rhizosphere soil of P. lactiflora, which were mainly related to the changes of dominant bacterial phyla, Chloroflexi, Metromirabilota, Actinobacteriota, and dominant fungal phyla, Chytridiomycota, Basidiomycota, Ascomycota. [Conclusion] The relative abundance of harmful fungi such as Ilyonia, Erysiphe and Fusarium increases significantly. The accumulation of pathogenic bacteria, the changes of enzyme activities, and the nutrient imbalance are the important reasons for the occurrence of root rot of P. lactiflora. [ABSTRACT FROM AUTHOR]