Microbial Community Response and Assembly Process of Yellow Sand Matrix in a Desert Marginal Zone Under Morchella Cultivation

Abstract

In this study, we investigated the adaptation of yellow-sand-substrate Morchella cultivation in the desert fringe and its effect on soil physicochemical properties and microbial communities. The qPCR and high-throughput sequencing with null modeling analyzed microbial diversity, networks, and assembly of Morchella cultivation under nutrient supplementation, linking physicochemical changes to microbial dynamics. The results showed that the yellow sand substrate can be planted with Morchella in the desert fringe area, as the Morchella cultivation with nutrient bags resulted in a yield of 691 g/m² of Morchella fruit units. Cultivation of Morchella could significantly increase the physicochemical properties of the yellow sand substrate, such as soil organic matter (SOM), total nitrogen (TN), ammonium nitrogen (NH₄⁺-N), and the microbial amount of carbon and nitrogen (MBC/MBN). The fungal community was dominated by Ascomycota, and Basidiomycota, Firmicutes, Bacteroidota, and Actinobacteriota. RDA analysis showed that Ascomycota and Proteobacteria were positively correlated with NH₄⁺-N, MBN, SOM, MBC, acting potassium (AK), TN, and C/N. Morchella cultivation promoted a positive correlation-dominant microbial network pattern in the yellow sand substrate. The nutrient bag treatment reduced bacterial network complexity while enhancing fungal network complexity, connectivity and stability, accompanied by significant increases in Proteobacteria, Bacteroidota, Cladosporium, and Thermomyces relative abundances during cultivation until original substrate degradation. Deterministic processes dominated bacterial and fungal communities, and morel cultivation drove bacterial and fungal community assembly toward heterogeneous selection processes. The results of the study revealed the economic value of Morchella cultivation in the desert fringe and the application potential of improving the physicochemical properties of yellow sandy soil, which is of great importance for practical cultivation and application of morel mushrooms in the desert.

Keywords: Morchella; co-occurrence network; microbial community; yellow sand substrate.

Figure 1

Shift of physiochemical chracteristics in the yellow sand substrate during Morchella cultivation. Note: SOM stands for soil organic matter, TN stands for total nitrogen, NH₄⁺−N stands for ammonium nitrogen, NO₃⁻−N stands for nitrate nitrogen, AK stands for available potassium, AP stands for available phosphorus, MBC stands for microbial biomass carbon, MBN stands for microbial biomass nitrogen, and C/N stands for carbon/nitrogen ratio. YSC stands for yellow sand substrate without Morchella cultivation, YSM stands for yellow sand substrate Morchella cultivation without nutrient bags, YSMN stands for yellow sand substrate Morchella cultivation with nutrient bags. Different lowercase letters indicate significant differences (p < 0.05) in the same treatment under different sampling time points, where black represents YSC treatment, blue represents YSM treatment, and red represents YSMN treatment.

Figure 1

Shift of physiochemical chracteristics in the yellow sand substrate during Morchella cultivation. Note: SOM stands for soil organic matter, TN stands for total nitrogen, NH₄⁺−N stands for ammonium nitrogen, NO₃⁻−N stands for nitrate nitrogen, AK stands for available potassium, AP stands for available phosphorus, MBC stands for microbial biomass carbon, MBN stands for microbial biomass nitrogen, and C/N stands for carbon/nitrogen ratio. YSC stands for yellow sand substrate without Morchella cultivation, YSM stands for yellow sand substrate Morchella cultivation without nutrient bags, YSMN stands for yellow sand substrate Morchella cultivation with nutrient bags. Different lowercase letters indicate significant differences (p < 0.05) in the same treatment under different sampling time points, where black represents YSC treatment, blue represents YSM treatment, and red represents YSMN treatment.

Figure 2

qPCR amplification curves (left) and melting curves (right) of plasmid samples of gene 16S (a) and ITS (b).

Figure 3

Effect of Morchella cultivation on bacteria copies(A) and fungi (B) copies in yellow sand substrate. A represents the time of sampling on day 0 after Morchella sowing. F represents the time of sampling on the 150th day after Morchella sowing. Different lowercase letters indicate significant differences (p < 0.05) in the different treatments.

Figure 4

Effect of Morchella cultivation on the number of bacterial (a) and fungal microbial OTUs in yellow sand substrate (b).

Figure 5

Microbial Alpha index of yellow sand substrate for Morchella Cultivation. (a) Bacterial in group; (b) Bacterial in time point; (c) Fungal in group; (d) Fungal in time point.

Figure 5

Microbial Alpha index of yellow sand substrate for Morchella Cultivation. (a) Bacterial in group; (b) Bacterial in time point; (c) Fungal in group; (d) Fungal in time point.

Figure 6

NMDS analysis of the bacterial community (a) and fungal community (b) in yellow sand substrate of Morchella cultivation.

Figure 7

Taxonomic composition of the microbial communities. (a) Bacterial phylum; (b) Bacterial genus; (c) Fungal phylum; (d) Fungal genus.

Figure 7

Taxonomic composition of the microbial communities. (a) Bacterial phylum; (b) Bacterial genus; (c) Fungal phylum; (d) Fungal genus.

Figure 8

LEfSe analysis: Biomarker taxa of the bacterial communities (a) and fungal communities (b).

Figure 9

RDA analysis of the correlation between the bacteria community (a) and fungal community (b) and environmental factors in yellow sand under Morchella cultivation.

Figure 10

Co-occurrence network analysis of soil microorganisms under Morchella cultivation.

Figure 11

Topological roles analysis of soil microorganism co-occurrence network under Morchella cultivation.