Influence of Arbuscular Mycorrhizal Fungi on Soybean Growth and Yield: A Metabarcoding Approach

This study evaluated the efficiency of arbuscular mycorrhizal fungi (AMF) in promoting the growth, yield, protein, and phytochemical contents of <i>Glycine max</i> cv. Morkhor 60. A completely randomized pot experiment was conducted for 90 days in non-sterile soil with nine replications. Three AMF species were tested and compared with two non-mycorrhizal controls, with and without NPK fertilizer. All AMF treatments enhanced plant growth, photosynthetic rate, and water-use efficiency compared with the unfertilized control. Inoculation with <i>Acaulospora dilatata</i> KKU-SK202 produced the highest pod number and increased 100-seed weight by 27.00% and 4.13% over the non-inoculated and NPK treatments, respectively. <i>Gigaspora margarita</i> KKU-SK210 yielded the highest total protein and phenolic contents, while <i>A. dilatata</i> KKU-SK401 showed the highest antioxidant activity (72.09%). Metabarcoding analysis revealed that AMF inoculation reduced root colonization by pathogenic fungi, with <i>G. margarita</i> KKU-SK210 and <i>A. dilatata</i> KKU-SK202 being the most effective. These results suggest that AMF inoculation can enhance soybean productivity and seed quality while reducing chemical fertilizer dependency and pathogenic fungal incidence.