Ecological response of Angelica dahurica and its rhizosphere microorganisms to the treatment of Alternanthera philoxeroides extracts

This study investigated the allelopathic effects of Alternanthera philoxeroides extracts on Angelica dahurica seedlings and soil enzyme activity to provide insights into its field management. Angelica Angelica Seedlings were treated with root, stem and leaf extracts at different concentrations, and physiological, biochemical, and soil enzymatic responses were analyzed. Furthermore, high-throughput sequencing was used to assess rhizosphere microbial diversity. Results showed that antioxidant enzyme (Superoxide dismutase, Peroxidase , Catalase) activity initially increased and then declined with rising extract concentration, with root extracts having the strongest inhibitory effect. Soil enzyme activity followed the order: root > stem > leaf, with soil enzymes soil β-glucosidase, soil Leucine Aminopeptidase and soil Alkaline phosphatase reaching peak levels at 80 g/L. Rhizosphere bacterial communities were dominated by Proteobacteria , Acidobacteria , Bacteroides and Sphingomonas . With increasing extract concentration, Proteobacteria , Bacteroidetes , and Sphingomonas increased, while Acidobacteria decreased. Principal component analysis revealed distinct shifts in bacterial community structure between treated and control samples. These findings provide a scientific basis for understanding the ecological adaptation of Angelica dahurica to Alternanthera philoxeroides invasion.