Tomato Intercropped with Potato-Onion Altered the Spore-Associated Bacterial Communities of Arbuscular Mycorrhizal Fungi in the Tomato Rhizosphere

Plant-plant interactions influence the abundance and diversity of AMF (Arbuscular Mycorrhizal Fungi) communities in the rhizosphere soil, which play a vital role in nutrient absorption, water utilization, and stress resistance. However, the mechanisms through which interspecific interactions shaping bacterial communities associated with AMF spores remains unclear. This study aimed to address this gap by using Illumina MiSeq sequencing to investigate the effects of tomato monoculture and tomato/potato-onion intercropping systems on the abundance, diversity, and composition of AMF spore-associated bacterial communities under greenhouse conditions. The results demonstrated that intercropping significantly enhanced the diversity of AMF spore-associated bacterial communities and altered their composition in the tomato rhizosphere. This shift increased the relative abundance of beneficial phyla, such as Actinobacteria and Cyanobacteria, bacterial classes including Alphaproteobacteria and Actinobacteria and bacterial genera like Janthinobacterium, Rhodococcus, Paenarthrobacter, and Streptomyces were more abundant in the intercropping system compared to monoculture. Furthermore, 156 distinct OTUs were identified, with 137 OTUs upregulated (primarily from Proteobacteria and Actinobacteria) and 19 OTUs downregulated (mostly from Proteobacteria and Bacteroidetes) compared to monoculture. The findings suggest that tomato/potato-onion intercropping significantly reshapes AMF spore-associated bacterial communities, enriching the abundance of potentially beneficial bacteria in the rhizosphere. This study emphasizes how optimal planting patterns can unlock vital soil biological mechanisms that improve plant growth through AMF inclusion. These findings offer innovative strategies for sustainable agriculture and provide valuable insight for ecosystem management to improve soil health and crop productivity.