Diversity of ectomycorrhizal fungi associated with Larixg melinii in Xinjiashan forest region of Qinling Mountains

Abstract:

[Objective] Larix gmelinii in Xinjiashan forest region of Qinling Mountains was taken as the object of this study, and its associated ectomycorrhizal fungi were observed and identified. [Methods] Field investigation was combined with identification methods of morphology and molecular biology to identify ectomycorrhizal fungi. [Results] There were 31 species of ectomycorrhizal fungi, belonging to 2 classes, 4 orders, 11 families and 11 genera. They were Tomentella, Inocybe, Russula, Amphinema, Laccaria, Sebacina, Amanita, Boletus, Cortinarius, Lactarius and Scleroderma; and Inocybe was the predominant group. The diversity of ectomycorrhizal fungi in sunny slope was higher than that in shady slope. The analyses about the chemical properties of mycorrhizosphere soil and non-mycorrhizosphere soil showed that the pH of mycorrhizosphere soil was significantly lower than that of non-mycorrhizosphere soil, while therapidly available phosphorus and potassium contents of mycorrhizosphere soil were significantly higher than those of non-mycorrhizosphere soil. The correlation analyses for chemical properties of mycorrhizosphere soil and ectomycorrhiza infection rate demonstrated that the ectomycorrhiza infection rate of Larix gmelinii was significantly positively correlated with soil pH, and was in extremely significant positive correlation with rapidly available potassium; while the infection rate was significantly negatively correlated with total nitrogen content and available phosphorus content. [Conclusion] The diversity of ectomycorrhizal fungi associated with Larix gmelinii was abundant, and it was affected by the slope aspect. Ectomycorrhizal fungi could reduce the pH of mycorrhizosphere soil, and increase the contents of organic matter, total nitrogen, rapidly available phosphorus, rapidly available potassium, soluble calcium and soluble magnesium of mycorrhizosphere soil. The ectomycorrhiza infection rate was affected by soil pH and contents of total nitrogen, available phosphorus and rapidly available potassium.

Key words:Larix gmelinii;ectomycorrhizal fungi;slope aspect;mycorrhizosphere;infection rate