庐山常绿落叶阔叶混交林土壤AM真菌资源及其分布特征

Soil AM fungal resources and its distribution characteristics in Lushan evergreen and deciduous broad-leaved mixed forest

  • 摘要: 【目的】探究庐山常绿落叶阔叶混交林土壤AM真菌群落多样性及分布特征,为推动其地下AM真菌资源的开发利用提供理论基础。【方法】以庐山典型常绿落叶阔叶混交林5种常见树种[(杜鹃(Rhododendron simsii)、蜡瓣花(Corylopsis sinensis)、山橿(Lindera reflexa)、女贞(Ligustrum lucidum)、榆树Ulmus pumila)]根际土壤丛枝菌根真菌(AM真菌)为材料,通过孢子形态学鉴定方法研究其多样性特征、影响因素及分布特征。【结果】从庐山常绿落叶阔叶混交林中鉴定、分离出55个AM真菌类群,其中包括2个广布种、10个常见种与43个稀有种(按优势度水平划分),其中无梗囊霉属(Acaulospora属,24种)和球囊霉属(Glomus属,18种)为优势属。此外,不同树种根际AM真菌孢子密度、物种丰富度、Shannon指数、Pielou均匀度指数等指标差异总体上不显著(P>0.05),且群落相似度系数较高,其中山橿(L.reflexa)与蜡瓣花(C.sinensis)根际AM真菌群落相似度系数最高(73.85%)。不同树种根际AM真菌种属分布存在差异,其中稀有内养囊霉(Entrophospora infrequens,稀有种之一)只在山橿根际有所发现,稀有种球囊霉17(Glomus.17)只在杜鹃(R.simsii)根际发现,稀有种亮色盾巨孢囊霉(Scutellospora fulgida)只在女贞(L.lucidum)根际发现,稀有种扭形伞房囊霉(Corymbiglomus tortuosum)只在蜡瓣花根际发现。不同树种根系侵染率水平存在显著差异(P<0.05),从高到低依次为蜡瓣花(45.72%)、榆树(U.pumila)(38.60%)、杜鹃和女贞(31.67%)、山橿(29.73%)。通过典范对应分析(CCA)发现土壤因子(全磷、全氮、氨态氮、硝态氮、有机质、pH和含水率)对土壤AM真菌群落变异的解释度为7.29%,而消除趋势对应分析(DCA)分析发现植物种类对土壤AM真菌群落变异的解释度为15.72%。【结论】庐山常绿落叶阔叶混交林土壤AM真菌是以稀有种为主的分布模式,该模式下的AM真菌及分布受宿主植物与土壤养分影响较小。

     

    Abstract: 【Objective】 In order to explore the diversity and distribution characteristics of AM fungi community in soil of evergreen and deciduous broad-leaved mixed forest in Lushan, and it provided theoretical basis to promote the development and utilization of underground AM fungal resources.【Method】 Five common tree species (Rhododendron simsii, Corylopsis sinensis, Lindera reflexa, Ligustrum lucidum, Ulmus pumila) rhizosphere siol arbuscular mycorrhizal fungi(AM fungi) diversity characteristics and influence factors analysis in Lushan typical evergreen and deciduous broad-leaved mixed forest were the grasp, and obtained its underground AM fungal diversity and distribution characteristics by spore morphology identification method.【Result】 Fifty-five AM fungi groups were identified and isolated from the Lushan evergreen and deciduous broad-leaved mixed forest, including 2 wide-spread species, 10 common species and 43 rare species (divided by level of dominance), among which Acaulospora(24 species) and Glomus(18 species) were the dominant genera. In addition, this study found that different tree species rhizosphere spore density of AM fungi community, the species abundance, diversity index and Pielou evenness index had no significant differences(P>0.05), and the community similarity coefficient was higher, L. reflexa and C. sinensis rhizosphere of AM fungi community similarity coefficient were the highest(73.85%). There were differences in the distribution of AM fungi in the rhizosphere of different tree species. Among them, Entrophospora infrequens(one of the rare species) was only found in the rhizosphere of L. reflexa, Glomus.17 was only found in the rhizosphere of R. simsii, and the rare species of Scutellospora fulgida was only found in the rhizosphere of L. lucidum. The rare species Corymbiglomus tortuosum only found in the rhizosphere of C. sinensis. The root infection rates of different tree species were significantly different (P<0.05), from high to low, they were C. sinensis(45.72%), U. pumila(38.60%), R. simsii and L. lucidum(31.67%), and L. reflexa(29.73%). According to canonical correspondence analysis(CCA), the explanatory degree of soil factors(total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen, organic matter, pH and moisture content) to the variation of soil AM fungal community was 7.29%, while according to the analysis of detrended correspondence analysis(DCA), the explanatory degree of plant species to the variation of soil AM fungal community was 15.72%.【Conclusion】 The distribution pattern of soil AM fungi in the evergreen and deciduous broad-leaved mixed forest of Lushan is mainly rare species, AM fungi and the distribution in this pattern are less affected by the host plants and soil nutrients.

     

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