Background and aims

Karst rocky desertification (KRD) influences soil properties and plant species. Soil microbes are important factors in maintaining ecosystem stability. However, little is known about the role of fungi in adaptation of plants to KRD.

Methods

Fungi colonized in bulk soil, rhizosphere, and roots of Themeda japonica at strong and slight KRD were analyzed by ITS2 amplicon sequencing. The relationship between soil nutrients and fungal diversity was estimated by redundancy analysis (RDA) and Spearman analysis.

Results

AN, NN, SOC, TN, TP content and pH in strong KRD soil were higher than those with slight KRD. Rhizosphere with slight KRD had higher fungal richness and diversity than it with strong KRD, but there was no difference in root endophyte between KRD grades. The bulk soil with slight KRD had higher fungal richness compare to strong KRD. The fungal communities in bulk soil, rhizosphere, and root between plants at different KRD grades were significantly different. In addition, the fungal communities of rhizosphere were sensitive to the change of KRD environment. Ascomycota and Basidiomycota were the predominant phyla in bulk soil, rhizosphere and root endophyte at strong and slight KRD. SOC, AN and pH influenced the composition of fungal communities at strong KRD. In contrast, TN and AN had a negative impact on richness.

Conclusion

Our results suggest that fungal communities of rhizosphere may play a role in adaptation of T. japonica to KRD and may contribute to promote plant growth and ecological performance in karst areas.

中文翻译：

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不同等级喀斯特石漠化条件下Themeda japonica植物的块状土壤，根际和根内生真菌群落的结构变异性

背景和目标

喀斯特石漠化（KRD）影响土壤性质和植物种类。土壤微生物是维持生态系统稳定的重要因素。但是，关于真菌在植物适应KRD中的作用知之甚少。

方法

散装土，根际和根定植菌黄背草在强大的和轻微的KRD被ITS2扩增子测序。通过冗余分析（RDA）和Spearman分析来估算土壤养分与真菌多样性之间的关系。

结果

强KRD土壤中的AN，NN，SOC，TN，TP含量和pH值均高于轻KRD土壤。轻度KRD的根际比强KRD的根际具有更高的真菌丰富性和多样性，但KRD等级之间的根内生植物没有差异。与强KRD相比，轻KRD的散装土壤具有较高的真菌丰富度。KRD等级不同的植物之间，土壤，根际和根部的真菌群落存在显着差异。此外，根际的真菌群落对KRD环境的变化敏感。在强弱KRD下，散装土壤，根际和根内生植物中的主要菌群是子囊菌和担子菌。SOC，AN和pH值影响强KRD时真菌群落的组成。相反，TN和AN对丰富度有负面影响。

结论

我们的结果表明，根际真菌群落可能在日本粳稻适应KRD的过程中发挥作用，并可能有助于促进喀斯特地区的植物生长和生态性能。