Environmental filtering affects fungal communities more than dispersal limitation in a high-elevation hyperarid basin on Qinghai-Tibet Plateau

Author(s):  
Rui Xing ◽  
Qing-bo Gao ◽  
Fa-qi Zhang ◽  
Jiu-li Wang ◽  
Shi-long Chen

Abstract The Qaidam Basin is the most extensive (120,000 km2) basin on the Qinghai-Tibet Plataea (QTP). Recent studies have shown that environmental selection and dispersal limitation influence the soil fungal community significantly in a large-scale distance. However, less is known about large-scale soil fungal community assemblages and its response to the elevation gradient in the high-elevation basin ecosystems. We studied fungal assemblages using Illumina sequencing of the ITS1 region from 35 sites of the Qaidam Basin. As the increase of elevation, fungal species richness and Chao1 index also increased. The Ascomycota was the most abundant phylum (more than 70% of total sequences), and six of the ten most abundance fungal family was detected in all 35 soil samples. The key factors influencing the soil fungal community composition in the Qaidam Basin were environmental filtering (soil properties and climate factors). The Mantel test showed no significant relationship between geographic distance and community similarity (r = 0.05 p = 0.81). The absence of the distance effect might be caused by lacking dispersal limitation for the soil fungal community.

2017 ◽  
Vol 67 (10) ◽  
pp. 679-689 ◽  
Author(s):  
Fei Xu ◽  
Tijiu Cai ◽  
Xue Yang ◽  
Wenzhi Sui

2019 ◽  
Vol 8 (10) ◽  
Author(s):  
Rui Xing ◽  
Qing‐bo Gao ◽  
Fa‐qi Zhang ◽  
Jiu‐li Wang ◽  
Shi‐long Chen

mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Pengfa Li ◽  
Weitao Li ◽  
Alex J. Dumbrell ◽  
Ming Liu ◽  
Guilong Li ◽  
...  

ABSTRACT Fungi underpin almost all terrestrial ecosystem functions, yet our understanding of their community ecology lags far behind that of other organisms. Here, red paddy soils in subtropical China were collected across a soil depth profile, comprising 0-to-10-cm- (0-10cm-), 10-20cm-, and 20-40cm-deep layers. Using Illumina MiSeq amplicon sequencing of the internal transcribed spacer (ITS) region, distance-decay relationships (DDRs), and ecological models, fungal assemblages and their spatial patterns were investigated from each soil depth. We observed significant spatial variation in fungal communities and found that environmental heterogeneity decreased with soil depth, while spatial variation in fungal communities showed the opposite trend. DDRs occurred only in 0-10cm- and 10-20cm-deep soil layers, not in the 20-40cm layer. Our analyses revealed that the fungal community assembly in the 0-10cm layer was primarily governed by environmental filtering and a high dispersal rate, while in the deeper layer (20-40cm), it was primarily governed by dispersal limitation with minimal environmental filtering. Both environmental filtering and dispersal limitation controlled fungal community assembly in the 10-20cm layer, with dispersal limitation playing the major role. Results demonstrate the decreasing importance of environmental filtering and an increase in the importance of dispersal limitation in structuring fungal communities from shallower to deeper soils. Effectively, “everything is everywhere, but the environment selects,” although only in shallower soils that are easily accessible to dispersive fungal propagules. This work highlights that perceived drivers of fungal community assembly are dependent on sampling depth, suggesting that caution is required when interpreting diversity patterns from samples that integrate across depths. IMPORTANCE In this work, Illumina MiSeq amplicon sequencing of the ITS region was used to investigate the spatial variation and assembly mechanisms of fungal communities from different soil layers across paddy fields in subtropical China, and the results demonstrate the decreasing importance of environmental filtering and an increase in the importance of dispersal limitation in structuring fungal communities from shallower to deeper soils. Therefore, the results of this study highlight that perceived drivers of fungal community assembly are dependent on sampling depth and suggest that caution is required when interpreting diversity patterns from samples that integrate across depths. This is the first study focusing on assemblages of fungal communities in different soil layers on a relatively large scale, and we thus believe that this study is of great importance to researchers and readers in microbial ecology, especially in microbial biogeography, because the results can provide sampling guidance in future studies of microbial biogeography.


2021 ◽  
Vol 7 (6) ◽  
pp. 420
Author(s):  
Wei Li ◽  
Shuo Shen ◽  
Hongyu Chen ◽  
Yang Zhang ◽  
Lei Deng ◽  
...  

The application of herbicides to arable land is still the most effective and accepted method to protect plants from weeds. Extensive use of chemicals in conventional agricultural practices has resulted in continuous and serious environmental pollution. Flurochloridone (FLC) is a monophenyl pyrrolidinone selective herbicide that is commonly used to inhibit weeds that occur during the growth of potatoes. In recent years, research on the toxicity of FLC has gradually increased. However, it is relatively rare to analyze the role of FLC by studying the composition of soil microorganisms. Therefore, we used NGS methods to identify the fungal community structure of the low content soil (LS) and high content soil (HS) samples in this study. Subsequently, we identified the fungal community and composition differences of these two group samples using the statistical analysis. Despite the variances of fungal community and composition across the different samples within the group, the fungal composition of the LS samples and the HS samples. LS samples were predominated by Ascomycota, while the HS samples were predominated by Mortierellomycota and Basidiomycota. The major species in the LS samples were Plectosphaerella cucumerina and Trichocladium asperum, whereas the dominant species in the HS samples were Epicoccum nigrum and Cladosporium chasmanthicola. These results suggested that the LS samples and the HS samples had different rhizosphere soil fungal community and composition changes resulting from implementation of FLC in potato growing areas.


Author(s):  
Zhi-Feng Zhang ◽  
Yue-Ping Pan ◽  
Yue Liu ◽  
Meng Li

Fungi are key components of microbial community in mangrove wetlands, with important roles in the transformation of nutrients and energy. However, existing studies typically focus on cultivable fungi, and seldomly on the structure and driving factors of the entire fungal communities. The compositions, community assembly and interaction patterns of mangrove fungal community on large scale remain elusive. Here, biogeography, assembly and co-occurrence patterns of fungal communities in mangrove across Eastern to Southern China were systematically analyzed by targeting the entire ITS region with high-throughput Pacific Biosciences single-molecule real-time sequencing. The analysis recovered a high level of fungal diversity, including a number of basal fungal lineages not previously reported in mangroves, such as Rozellomycota and Chytridiomycota . Beta nearest-taxon index analyses suggested a determinant role of dispersal limitation on fungal community in overall and most individual mangroves, with supporting from the strong distance-decay patterns of community similarity. Further, nonmetric multidimensional scaling analyses revealed a similar biogeography of dominant and rare fungal community. A minor role of environmental selection on the fungal community was noted, with geographical location and sediment depth as crucial factors driving the distribution of both, the dominant and rare taxa. Finally, network analysis revealed high modularized co-occurrence patterns of fungal community in mangrove sediments, and the keystone taxa might play important roles in microbial interactions and ecological functions. The investigation expands our understanding of biogeography, assembly patterns, driving factors, and co-occurrence relationships of mangrove fungi, and will spur the further functional exploration and protection of fungal resources in mangrove. IMPORTANCE As key components of microbial community in mangroves, fungi have important ecological functions. However, fungal community in mangrove on large scale is generally elusive, and mangroves are declining rapidly due to climate change and anthropogenic activities. This work provided an overview of fungal community structure and biogeography in mangrove wetlands along an over-9000 km coastline across Eastern to Southern China. Our study observed a high number of basal fungal lineages in mangrove sediments, such as Rozellomycota and Chytridiomycota . In addition, our results highlighted a crucial role of dispersal limitation and a minor role of environmental selections on fungal community in mangrove sediments. These novel findings add important knowledge about the structure, assembly processes, and driving factors of fungal community in mangrove sediments.


2020 ◽  
Author(s):  
Guillaume Lentendu ◽  
Micah Dunthorn

AbstractWe used two large-scale metabarcoding datasets to evaluate phylogenetic signals at global marine and regional terrestrial scales using co-occurrence and co-exclusion networks. Phylogenetic relatedness was estimated using either global pairwise sequence distance or phylogenetic distance and the significance of observed patterns relating networks and phylogenies were evaluated against two null models. In all datasets, we found that phylogenetically close OTUs significantly co-occurred more often, and OTUs with intermediate phylogenetic relatedness co-occurred less often, than expected by chance. Phylogenetically close OTUs co-excluded less often than expected by chance in the marine datasets only. Simultaneous excess of co-occurrences and co-exclusions were observed in the inversion zone between close and intermediate phylogenetic distance classes in marine surface. Similar patterns were observed by using either pairwise sequence or phylogenetic distances, and by using both null models. These results suggest that environmental filtering and dispersal limitation are the preponderant forces driving co-occurrence of protists in both environments, while signal of competitive exclusion was only detected in the marine surface environment. The discrepancy in the co-exclusion pattern is potentially linked to the individual environments: water bodies are more homogeneous while tropical forest soils contain a myriad of nutrient rich micro-environment reducing the strength of mutual exclusion.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6962
Author(s):  
Xing Li ◽  
Tianming Li ◽  
Delong Meng ◽  
Tianbo Liu ◽  
Yongjun Liu ◽  
...  

Background The soil fungal community plays an important role in global carbon cycling and shows obvious seasonal variations, however, drivers, particularly stochastic drivers, of the seasonal variation in the fungal community have never been addressed in sufficient detail. Methods We investigated the soil fungal community variation between summer growing (SG) and winter fallow (WF) stage, through high throughput sequencing of internal transcribed spacer (ITS) amplicons. Subsequently, we assessed the contribution of different ecological processes to community assembly using null-model-based statistical framework. Results The results showed that the fungal community diversity decreased significantly after tobacco cropping in the SG stage and the composition showed a clear turnover between the WF and SG stages. The variation in community composition was largely attributable to the presence of a small portion of Dothideomycetes in the WF stage that dominated the soil fungal community in the SG stage. The organic matter, temperature, and water content were the main deterministic factors that regulated the fungal community; these factors explained 34.02% of the fungal community variation. Together with the result that the fungal community was mainly assembled by the dispersal process, our results suggested that the stochastic factors played important roles in driving the seasonal variation of fungal community. The dispersal limitation dominated the fungal community assembly during the WF stage when homogenizing dispersal was the main assembly process of the fungal community in the SG stage. Thus, we proposed that the dispersal processes are important drivers for seasonal variation of fungal community in tobacco planted soil.


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