Characteristics of the Fungal Communities and Co-occurrence Networks in Hazelnut Tree Root Endospheres and Rhizosphere Soil

Abstract

Hazelnut has gained economic value in China in recent years, but its large-scale planting and research started later than other countries. Conducting basic research on hazelnut trees requires studying their related microorganisms. Here, we used high-throughput DNA sequencing to quantify the fungal communities in the root endospheres and rhizosphere soil of four hazelnut species. Fungal diversity in the rhizosphere soil was significantly higher than that in the root endospheres. Rhizosphere soil had more Mortierellomycota, and the fungal community compositions differed among the four hazelnut species. The root endospheres, especially those of the Ping’ou (Corylus heterophylla × Corylus avellana) trees, contained more ectomycorrhizal fungi. The co-occurrence networks in the rhizosphere soil were more sophisticated and stable than those in the root endospheres, even when the root endospheres had higher modularity, because the structural differentiation of the root endospheres differed from that of the rhizosphere soil. Two-factor correlation network analysis and linear regression analysis showed that the total organic carbon was the main environmental factor affecting the fungal communities. Our study revealed the community compositions, functional predictions, and co-occurrence network structural characteristics of fungi in hazelnut root endospheres and rhizosphere soil. We also examined the potential keystone taxa, and analyzed the environmental factors of the dominant fungal community compositions. This study provides guidance for the growth of hazelnut and the management of hazelnut garden, and provides an insight for future development of fungal inoculants to be used in hazelnut root.

The effect of shrubs admixture in pine forest stands on soil bacterial and fungal communities and accumulation of polycyclic aromatic hydrocarbons

“…In pine stands without shrubs proportion of these phyla was comparable. The dominance of the Ascomycota group was also found in the study of the structure of fungal populations in the root zone of various species of hazelnut 50 . It seems that high rate of this phylum is vulnerable from the point of view the ability of fungi to decompose of PAHs.…”

Microbial community composition and Co-occurrence network analysis of the rhizosphere soil of the main constructive tree species in Helan Mountain of Northwest China

“…A lower level of modularity indicates that cross-module associations between different groups may be more common 48 . If environmental interference affects some modules, then this impact may spread to other modules 17 . It is worth mentioning that there are more positive rather than competitive relationships in fungal communities, possibly because these fungi have sufficient resources.…”

“…In addition, the modularity exhibited in microbial networks is also a focus of research. The complexity and diversity of microbial communities can be revealed based on the greedy modularity optimization method 17 , and key taxa (Connector hubs and Module hubs) in co-occurrence networks can be identified through highly correlated taxonomic groups 18,19 . These key groups are crucial for maintaining network stability and the functionality of specific ecosystems 20 .…”

Effects of SMOF on soil properties, root-zone microbial community structure, metabolites, and maize (Zea mays L.) response on a reclaimed barren mountainous land

“…In this study, we applied correlation-based network results to analyze the interaction between OTUs of different treatments (Sparcc's correlation N > 0.5 or <−0.5, p < 0.01). It is well-known that more nodes and edges and higher community diversity represent a complex and stable network structure (Hernandez et al, 2021 ), and high modularity is also an indicator of the network's structural stability (Ma et al, 2021 ). In our study, four different treatments had different microbial co-occurrence network structures.…”