Continuous Cropping Is Associated with Shifts in Diversit of Strawberry Root Associated Bacteria

Strawberry is a fruit crop with high economic value, but its production is severely limited by continuous cropping obstacles. At a single sampling time point in May 2023, we compared 16S rRNA amplicon sequencing and FAPROTAX functional prediction were used to systematically analyze the effects of continuous cropping on the strawberry root endophytic bacterial community. Continuous cropping significantly reduced bacterial richness, with the number of amplicon sequence variants (ASVs) decreasing from 2,506 to 2,144, and also altered community composition. At the phylum level, the abundance of Actinobacteria decreased from 30.50% to 12.85%, while Bacteroidota increased from 1.64% to 5.68%. The abundances of Streptomyces (biocontrol-related) and Bradyrhizobium (nitrogen-fixing) were significantly reduced. In addition, the decline of several highly connected genera in the co-occurrence network suggested altered network topology under continuous cropping.. Functional prediction showed that chemoheterotrophy and nitrogen fixation decreased by 8.7% and 0.53%, respectively, whereas methylotrophy and ureolysis increased by 5.6% and 12.2%. These results suggest that continuous cropping was associated with shifts in bacterial community composition, co-occurrence patterns, and FAPROTAX-predicted carbon- and nitrogen-related functional groups in strawberry roots.. This study provides a theoretical foundation for alleviating continuous cropping obstacles through microbial regulation strategies in future strawberry cultivation.