秦岭辛家山林区落叶松外生菌根真菌多样性

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

【目的】以秦岭辛家山林区落叶松为研究对象,观察鉴定与其共生的外生菌根真菌。【方法】通过野外调查结合形态学和分子生物学鉴定方法。【结果】鉴定出31种外生菌根真菌,分属2门4目11科11属,分别有毛革菌属(Tomentella)、丝盖伞属(Inocybe)、红菇属(Russula)、Amphinema、蜡蘑属(Laccaria)、蜡壳耳属(Sebacina)、鹅膏菌属(Amanita)、牛肝菌属(Boletus)、丝膜菌属(Cortinarius)、乳菇属(Lactarius)和硬皮马勃属(Scleroderma),丝盖伞属是优势类群。阳坡外生菌根真菌多样性高于阴坡。对菌根根际土与非根际土化学性质分析表明,pH值显著低于非根际,速效磷、速效钾含量显著高于非根际。对根际土化学性质与外生菌根侵染率相关性分析表明,落叶松外生菌根侵染率与土壤pH值呈显著正相关;与速效钾呈极显著正相关;与全氮、速效磷呈显著负相关。【结论】落叶松外生菌根真菌多样性丰富,且受坡向影响。外生菌根真菌可降低根际pH,提高根际有机质、全氮、速效磷、速效钾、水溶性钙和水溶性镁的含量。外生菌根侵染率受土壤pH值、全氮、速效磷、速效钾的影响。

[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. [Methodsl 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-myeorrhizosphere soil. The correlation analyses for chemical properties of mycorrhizosphere soil and ectomyeorrhiza 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 gmeBnii 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.