丛枝菌根真菌对宁夏枸杞生长的影响 postprint

Abstract: This study aimed to elucidate the growth-promoting effects and underlying mechanisms of exogenous inoculation with arbuscular mycorrhizal (AM) fungi on Lycium barbarum under natural field conditions, with the goal of advancing mycorrhizal technology in the L. barbarum industry. Lycium barbarum 'Ningqi No. 9' was used as the plant material, and Rhizophagus intraradices and Funneliformis mosseae served as the test inoculants. A field plot experiment was conducted at the Huinong L. barbarum Planting Base in Ningxia, comprising two treatments: inoculation with AM fungi (AM) and a non-inoculated control (NM). Parameters assessed included plant growth, root mycorrhizal colonization rate, rhizosphere soil physicochemical properties, and fungal community structure. The results demonstrated that, relative to the NM treatment, the AM treatment significantly enhanced plant height (P < 0.001) and stem diameter (P = 0.032) of L. barbarum, and increased the concentrations of total phosphorus, total potassium, and available potassium in the rhizosphere soil. Furthermore, AM inoculation altered the beta-diversity of the rhizosphere fungal community and fostered a more complex, densely connected, and efficient fungal co-occurrence network, as evidenced by higher node counts and connectivity, along with reduced average path length and betweenness centrality. The AM treatment also decreased the relative abundance of indigenous AM fungi while increasing both the relative abundance and diversity of plant pathogenic fungi. Notably, root mycorrhizal colonization rate was not significantly affected. Hierarchical partitioning analysis revealed that attributes of the fungal co-occurrence network accounted for the largest proportion of the variance in L. barbarum growth (33.86%), followed by soil phosphorus and potassium nutrient status (30.78%), plant pathogenic fungi (19.40%), and saprophytic fungi (9.82%). In conclusion, the growth-promoting effect of AM fungi on L. barbarum is primarily achieved through the restructuring of the rhizosphere fungal interaction network, the enhancement of soil phosphorus and potassium availability, and the modulation of the balance between pathogenic and saprophytic fungi, rather than through the conventional mechanism of high mycorrhizal colonization. These findings offer a novel perspective for microbial management strategies in L. barbarum cultivation within arid regions.