Differential impacts of Funneliformis Mosseae and Rhizophagus intraradices on the rice rhizosphere microbiome, nutrient availability, and yield in paddy fields.

Abstract

While the positive impact of arbuscular mycorrhizal fungi (AMF) on rice growth has been well documented, the specific mechanisms by which different AMF species regulate rice growth and the rhizosphere microecosystem are not fully understood. This research investigated two AMF species, Funneliformis mosseae (Fm) and Rhizophagus intraradices (Ri), to elucidate their effects on rice rhizosphere soil characteristics, microbial community structure, and rice yield. Field experiments showed that treatment with Fm resulted in significantly yields (26.96%) compared to Ri (21.19%). Although both AMF species significantly increased mycorrhizal colonization rates compared to the control (Fm: 78.23%, Ri: 70.13% at maturity), they induced distinct improvements in soil properties. Specifically, Fm significantly boosted soil enzyme activities, increasing urease and cellulase activities by 47.29% and 24.62%, respectively, compared to Ri, Conversely, Ri promoted the accumulation of soil available phosphorus (69.81% higher than Fm). Additionally, the two AMF strains influenced the rhizosphere microbial community through different regulatory mechanisms. Fm significantly enriched bacterial taxa related to carbon cycling, such as Chloroflexota and Actinomycetota. Ri not only significantly increased microbial α-diversity but also specifically enriched bacterial function groups related to sulfur cycling. Crucially, the two AMF species optimized interactions between AMF, rice plants, and rhizosphere microorganisms via different structural modifications. Under Fm, fungal community network modularity was significantly higher, while the bacterial network under Ri treatment exhibited stronger connectivity. This study elucidates the distinct mechanisms by which AMF species synergistically enhance rhizosphere soil microenvironmental quality and increase rice yield. These findings provide a theoretical basis for the sustainable management of rice fields and suggest new directions for developing environmentally friendly agricultural technologies.