Effects of Suillus luteus on growth promotion and root phosphorus activation and absorption of Pinus sylvestris var. Mongolica

Abstract Aims: Pinus sylvestris var. Mongolica is a major afforestation tree species in northern China. However, the soil in the natural growth area of P. sylvestris var. Mongolica often lacks nutrients. Applying ectomycorrhizal fungi (ECMF) to seedlings can effectively enhance their root system's absorption of phosphorus. However, how does mycorrhizal fungi activate insoluble phosphorus elements in the rhizosphere? The purpose of this study is to explain how ectomycorrhizal fungi activate insoluble phosphorus in the rhizosphere of seedlings into soluble phosphorus, which is supplied to seedlings for absorption. Methods：P. sylvestris var. Mongolica seedlings were inoculated with Suillus luteus to study the efficacy of ECMF on the performance of P. sylvestris var. Mongolica seedlings. At the same time, the effects of S. luteus on the activation of P in the interrhizosphere and the absorption of P in the rhizosphere of P. sylvestrisvar. Mongolica were studied by using a space-division grid device. Results：The outcome expressed that S. luteus treatment could enhance the seedling growth. The content of cellulose and lignin increased by 9.36% and 31.16%; And the root growth was significantly improved. Inoculation with ECMF significantly reduced soil pH, and the release of acid phosphatase and organic acids led to a significant increase in soil active phosphorus content. Meanwhile, ECMF could increase P content in root and leaf of P. sylvestris var. Mongolica. Conclusion：S. luteus can activate soil phosphorus, promote the absorption and turnover of P by P. sylvestris var. Mongolica, and improve growth potential.