Effects of Ectomycorrhizal Fungi on the Activation and Uptake of Phosphorus in the Mycorrhizal and Hypodermal Layers of Populus davidiana × P. bolleana

In this study, we investigated the activation and uptake of soil phosphorus by ectomycorrhizal fungi. We used Populus davidiana × Populus bolleana tissue culture-generated seedlings to conduct experiments. Inoculation was performed with two ectomycorrhizal fungi: Suillus luteus and Paxillus involutus. Our results showed that inoculation with S. luteus and P. involutus significantly increased the height, ground diameter, biomass, and tissue phosphorus content of P. davidiana × P. bolleana seedlings. Simultaneously, it decreased the soil pH and increased the soil acid phosphatase activity and soil effective phosphorus content. All effects on the mycorrhizosphere were greater than those on the hyphosphere. These findings indicated that the introduction of ectomycorrhizal fungi acidified the soil, increased the activity of soil acid phosphatase, promoted the decomposition of phosphate in the insoluble state of the soil, and increased the effective phosphorus content in the soil, thus promoting the uptake of phosphorus in plants and playing a role in the growth of P. davidiana × P. bolleana. Among them, mycorrhizae affected the soil to a greater extent than hyphae.