Structural variability in the bulk soil, rhizosphere, and root endophyte fungal communities of Themeda japonica plants under different grades of karst rocky desertification


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.

Plant and Soil