Fungal-Bacterial Networks in the Habitat of SongRong (Tricholoma matsutake) and Driving Factors of Their Distribution Rules

Abstract

Soil origin, mycorrhizal plant partners and environmental factors affect the growth and development of SongRong (Tricholoma matsutake). In order to clarify the relationships of fungi-bacteria networks and various influence factors in the habitat of SongRong, we chose three collection sites with a Quercus mongolica pure forest (plot A without SongRong was used as the control sample site), Q. mongolica mixed Rhododendron dauricum (plot B) and Q. mongolica mixed with R. dauricum and Pinus densiflora (plot C). By using high-throughput sequencing, we obtained a total of 4930 fungal and 55501 bacterial amplicon sequence variants (ASVs) based on internally transcribed spacer ribosomal RNA (ITS rRNA) and 16S ribosomal RNA (16S rRNA) sequencing via the Illumina NovaSeq platform. In the habitat soil of SongRong (plot B and plot C), alpha or beta diversity and species compositions of fungi and bacteria were different from plot A. The fungal-bacterial networks follow the selection rule that few dominant genera account for the greater relative abundance. Forest types, but not the host itself, drove the fungal-bacterial networks of the forest soil, and soil physicochemical characteristics and texture affected their abundance. The abundance of Tricholoma was affected by the fungal and bacterial abundance in the habitat.

Keywords: Tricholoma matsutake; forestry types; fungi–bacterial networks; mixed forest with Quercus mongolica; soil physicochemical parameters; soil structure.

Figure 1

Bacterial community in the soil from three collection sites: (a) NMDS analysis of bacterial β-diversity from three collective sites, (b) alpha diversity of bacteria, the asterisk (*) represents a significant difference at p < 0.05 level, (c) Venn map of bacteria, (d) a heat map of the bacteria composition of the first 20 genera. PA, soil sample from plot A; PB, soil sample from plot B; PC, soil sample from plot C.

Figure 2

Fungal community in the soil from three collection sites: (a) NMDS analysis of fungal beta diversity, (b) alpha diversity of fungi, (c) Venn map of fungi from three soil samples, (d) a heat map of the fungi composition of the first 20 genera. (e) Functional guild cluster diagram of fungi of the first 20 genera. ECMF: ectomycorrhizal fungi; ERMF, ericoid mycorrhizal fungi; SAF, saprotrophic fungi. PA, soil sample from plot A; PB, soil sample from plot B; PC, soil sample from plot C.

Figure 3

The relationships of soil physicochemical factors with (a) bacteria and (b) fungal communities in soil with different collection sites. PA, soil samples from plot A; PB, soil samples from plot B; PC, soil samples from plot C.

Figure 4

International triangulation of soil texture. PA, soil samples from plot A; PB, soil samples from plot B; PC, soil samples from plot C.

Figure 5

The relationships of soil texture factors with (a) bacteria and (b) fungal communities in soil with different collection sites. PA, soil samples from plot A; PB, soil samples from plot B; PC, soil samples from plot C.