scholarly journals Changes in Fungal Community Structure in Freshwater Canals across a Gradient of Urbanization

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1917
Author(s):  
Tianma Yuan ◽  
Haihan Zhang ◽  
Qiaoli Feng ◽  
Xiangyu Wu ◽  
Yixin Zhang ◽  
...  

Fungi are an important, yet often, neglected component of the aquatic microflora, and is responsible for primary decomposition and further processing of organic matter. By comparison, the ecological roles of terrestrial fungi have been well-studied, but the diversity and function of fungi that populate aquatic environments remain poorly understood. Here, the impact of urbanization on fungal diversity and community composition in the canal system of Suzhou was assessed by sequencing the internal transcribed spacer 1 (ITS1) region of the rRNA operon. It was amplified from environmental DNA that has been extracted from water samples and pre-deployed decomposing leaves collected from nine sampling locations (high, medium and low urbanization) over two seasons. The fungal diversity and community composition were determined by bioinformatic analysis of the large DNA sequence datasets generated to identify operational taxonomic units (OTUs) for phylogenetic assignment; over 1 million amplicons were sequenced from 36 samples. The alpha-diversity estimates showed high differences in fungal diversity between water and leaf samples, and winter versus summer. Higher numbers of fungal OTUs were identified in both water and leaf samples collected in the summer, and fungal diversity was also generally higher in water than on colonized leaves in both seasons. The fungal community on leaves was usually dominated by Ascomycetes, especially in winter, while water samples contained more diversity at phylum level with Chytridiomycetes often prominent, particularly in summer. At a genus level, a very high relative abundance of Alternaria on leaves was observed in winter at all locations, in contrast to very low abundance of this genus across all water samples. Fungal community composition also varied between sampling locations (i.e., urbanization); in cluster analysis, samples from high urbanization locations formed a distinct cluster, with medium and low urbanization samples clustering together or in some instances, separately. Redundancy analysis shed further light on the relationships between variation in fungal community composition and water physico-chemical properties. Fungal community diversity variation and correlation with different parameters is discussed in detail, but overall, the influence of season outweighed that of urbanization. This study is significant in cataloguing the impact of urbanization on fungal diversity to inform future restoration of urban canal systems on the importance of protecting the natural aquatic fungal flora.

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Zaihua He ◽  
Qiang Li ◽  
Xiaoyi Zeng ◽  
Kai Tian ◽  
Xiangshi Kong ◽  
...  

Abstract Peat, as a heterogeneous mixture of decaying plant debris and microbial residues, has been widely used in many fields. However, little research focused on the impact of peat addition on food waste composting. To fill this gap, a composting experiment of food waste mixed with five varying percent peat 0, 5, 10, 15, and 20% (w/w, dry weight) was designed to investigate the effect of different dosages of peat on nitrogen conservation, physiochemical parameters, and fungal community dynamics during composting. The results showed that adding peat elevated the peak temperature of composting, lowered final pH, reduced ammonia emissions and increased the final total nitrogen content. Compared to control, adding 5, 10, 15, and 20% peat decreased ammonia emissions by 1.91, 10.79, 23.73, and 18.26%, respectively, during 42 days of composting. Moreover, peat addition increased fungal community diversity especially during maturation phase. The most two abundant phyla were Basidiomycota and Ascomycota in all treatments throughout the composting process. At the end of composting, in treatments with adding 10 and 15% peat, the richest fungi were Scedosporium spp. and Coprinopsis spp., respectively. Simultaneously, canonical correlation analyses showed that pH, moisture content, and seed germination index had significant association with fungal community composition. The study also showed that fungal community and nitrogen conservation had no direct obvious relation during composting. Overall, the results suggest that the addition of peat could efficiently enhance nitrogen conservation through reduction of ammonia emissions and 15% peat addition is the optimal formula for food waste composting.


Author(s):  
Kaire Loit ◽  
Liina Soonvald ◽  
Alar Astover ◽  
Eve Runno-Paurson ◽  
Maarja Öpik ◽  
...  

The rhizosphere fungal community can play an important role in determining plant growth and health. In this study, using high-throughput sequencing, we investigated the fungal diversity and community composition in the roots and rhizosphere soil of 21 potato (Solanum tuberosum L.) cultivars. The samples were collected at three different sampling points. Furthermore, we assessed the differences in both diversity and composition of pathogen and saprotroph communities. In soil and roots, the fungal richness and relative abundance of pathogens and saprotrophs were mainly affected by sampling time. However, root fungal communities were also significantly affected by cultivar. The most substantial effect of cultivar was on root pathogen diversity. Moreover, the occurrence of most pathogens strongly varied among cultivars. Soil fungal community composition was primarily determined by sampling time; whereas in roots, the primary determinant was cultivar. Our results demonstrate changes in fungal communities over the potato growing season, as well as highlight the importance of potato cultivar on root fungal communities, and emphasise their importance in plant breeding.


2020 ◽  
Author(s):  
Wei Zheng ◽  
Zhiyuan Zhao ◽  
Fenglian Lv ◽  
Yanan Yin ◽  
Zhaohui Wang ◽  
...  

Abstract Background In soil ecosystems, bacteria and fungi always co-exist in the same niche and interact with each other, especially in different sized soil aggregates. The bacterial and fungal community assembly process and bacteria-fungi interactions in soil aggregates, which is important for bacterial and fungal community diversity and composition, is still unclear.Methods We examined bacterial and fungal community assembly in soil macroaggregate (> 0.25 mm), microaggregate (0.053–0.25 mm) and smaller microaggregate (silt + clay, < 0.053 mm) in an apple orchard. The microbial community assembly processes were analyzed by normalized stochasticity ratio index (NST).Results Bacterial community diversity, composition and assembly were more affected by agricultural practice and aggregate than fungal community. Bacterial community assembly was more stochastic in silt + clay than in macroaggregate, and was more stochastic (NST > 50%) than fungal community in soil aggregates. Meanwhile, bacterial NST was negatively correlated with fungal diversity, and fungal NST was positively correlated with fungal diversity. Co-occurrence network suggested that the bacteria and fungi were less strongly interacting in the network of silt + clay, compared to macroaggregate. The results indicated that fungi impact on the bacterial community assembly in soil aggregate, and the stochasticity of bacterial community assembly was increased with the decrease of interaction between bacteria and fungi in soil aggregates.Conclusions This study enhances our understanding of the mechanism of bacterial and fungal community assembly and co-exists pattern of bacteria and fungi in soil aggregates.


2021 ◽  
Vol 53 (1) ◽  
pp. 93-100
Author(s):  
X.H. Zhang ◽  
H.L Xie ◽  
Y.Y. Wang ◽  
X.G. Zhou

In pot culture, we evaluated the effects of green manure of wild rocket (Diplotaxis tenuifolia (L.) DC.) on cucumber (Cucumis sativus L.) rhizosphere fungal community composition. Cucumber rhizosphere fungal composition was analyzed by high-throughput amplicon sequencing of fungal ITS regions. Results showed that cucumber seedling rhizosphere fungal community composition was different between the fallow treatment and green manure treatment. However, green manure treatment did not affect the cucumber seedlings fungal community alpha diversity. Compared with the fallow treatment, cucumber grown in green manure of wild rocket had higher relative abundance of phylum Ascomycota but lower relative abundance of phylum Zygomycota. Moreover, green manure of wild rocket decreased operational taxonomic units (OTUs) classified as Pseudallescheria and Kernia spp. but increased OTUs classified as Humicola and Fusarium spp. in cucumber rhizosphere.


2020 ◽  
Vol 12 (14) ◽  
pp. 5835
Author(s):  
Makoto Kanasugi ◽  
Elsie Sarkodee-Addo ◽  
Richard Ansong Omari ◽  
Khondoker Mohammad Golam Dastogeer ◽  
Yoshiharu Fujii ◽  
...  

We investigated the root microbiomes of rice sampled from six major rice-producing regions in Ghana using Illumina MiSeq high-throughput amplicon sequencing analysis. The result showed that both bacterial and fungal community compositions were significantly varied across the regions. Bacterial communities were shaped predominantly by biotic factors, including root fungal diversity and abundance. In contrast, fungal communities were influenced by abiotic factors such as soil nitrate, total carbon and soil pH. A negative correlation between the diversity and abundance of root fungi with soil nitrate (NO3-) level was observed. It suggested that there were direct and indirect effects of NO3- on the root-associated bacterial and fungal community composition. The gradient of soil nitrate from North to South parts of Ghana may influence the composition of rice root microbiome. Bacterial community composition was shaped by fungal diversity and abundance; whereas fungal community composition was shaped by bacterial abundance. It suggested the mutualistic interaction of bacteria and fungi at the community level in the rice root microbiome. Specific bacterial and fungal taxa were detected abundantly in the ‘Northern’ regions of Ghana, which were very low or absent from the samples of other regions. The analysis of indicator species suggested that an ‘ecological specialization’ may have occurred which enabled specific microbial taxa to adapt to the local environment, such as the low-nitrate condition in the Northern regions.


2021 ◽  
Vol 2 ◽  
Author(s):  
Stefanie Hoeber ◽  
Christel Baum ◽  
Martin Weih ◽  
Stefano Manzoni ◽  
Petra Fransson

Soil fungi are strongly affected by plant species or genotypes since plants modify their surrounding environment, but the effects of plant genotype diversity on fungal diversity and function have not been extensively studied. The interactive responses of fungal community composition to plant genotypic diversity and environmental drivers were investigated in Salix biomass systems, posing questions about: (1) How fungal diversity varies as a function of plant genotype diversity; (2) If plant genotype identity is a strong driver of fungal community composition also in plant mixtures; (3) How the fungal communities change through time (seasonally and interannually)?; and (4) Will the proportion of ECM fungi increase over the rotation? Soil samples were collected over 4 years, starting preplanting from two Salix field trials, including four genotypes with contrasting phenology and functional traits, and genotypes were grown in all possible combinations (four genotypes in Uppsala, Sweden, two in Rostock, Germany). Fungal communities were identified, using Pacific Biosciences sequencing of fungal ITS2 amplicons. We found some site-dependent relationships between fungal community composition and genotype or diversity level, and site accounted for the largest part of the variation in fungal community composition. Rostock had a more homogenous community structure, with significant effects of genotype, diversity level, and the presence of one genotype (“Loden”) on fungal community composition. Soil properties and plant and litter traits contributed to explaining the variation in fungal species composition. The within-season variation in composition was of a similar magnitude to the year-to-year variation. The proportion of ECM fungi increased over time irrespective of plant genotype diversity, and, in Uppsala, the 4-mixture showed a weaker response than other combinations. Species richness was generally higher in Uppsala compared with that in Rostock and increased over time, but did not increase with plant genotype diversity. This significant site-specificity underlines the need for consideration of diverse sites to draw general conclusions of temporal variations and functioning of fungal communities. A significant increase in ECM colonization of soil under the pioneer tree Salix on agricultural soils was evident and points to changed litter decomposition and soil carbon dynamics during Salix growth.


2020 ◽  
Author(s):  
Magdalena Wutkowska ◽  
Dorothee Ehrich ◽  
Sunil Mundra ◽  
Anna Vader ◽  
Pernille B. Eidesen

ABSTRACTArctic plants are affected by many stressors. Root-associated fungi are thought to influence plant performance in stressful environmental conditions. However, the relationships are not transparent; do the number of fungal partners, their ecological functions and community composition mediate the impact of environmental conditions and/or influence host plant performance? To address these questions, we used a common arctic plant as a model system: Bistorta vivipara. Whole plants (including root system) were collected from nine locations in Spitsbergen (n=214). Morphometric features were measured as a proxy for performance and combined with metabarcoding datasets of their root-associated fungi (amplicon sequence variants, ASVs), edaphic and meteorological variables. Seven biological hypotheses regarding fungal influence on plant measures were tested using structural equation modelling. The best-fitting model revealed that local temperature affected plants both directly (negatively aboveground and positively below-ground) and indirectly - mediated by fungal richness and the ratio of symbio- and saprotrophic ASVs. Fungal community composition did not impact plant measurements and plant reproductive investment did not depend on any fungal parameters. The lack of impact of fungal community composition on plant performance suggests that the functional importance of fungi is more important than their identity. The influence of temperature on host plants is therefore complex and should be examined further.


2016 ◽  
Vol 59 (5) ◽  
Author(s):  
Amy L. Salamone ◽  
Brent M. Robicheau ◽  
Allison K. Walker

AbstractWe present the first characterization of fungal community diversity of natural mixed-species biofilms on artificial marine reefs. Four artificial reefs in the Mississippi (MS) Sound, USA, representing low-profile (underwater) and high-profile (periodically air-exposed) conditions were sampled every 3 months over a 23-month period to investigate changes in fungal diversity within reef biofilms. Fungal presence was assessed via PCR amplification of the internal transcribed spacer (ITS) region of fungal ribosomal DNA, and by terminal restriction fragment length polymorphism (T-RFLP) analysis of fungal ITS regions – the latter being used to track variation in fungal community structure with respect to season, location, and reef profile type. Fungal communities were also characterized taxonomically through both morphological identification and phylogenetic comparisons of ITS gene sequences, with 36 fungal genera cultured from reef biofilms. Using a multivariate statistical approach, significant temporal and spatial differences in fungal biofilm communities were detected. High-profile reefs differed significantly in biofilm fungal community composition across the 10 sampling periods. This assessment of marine fungal biofilm communities over time provides novel insights into the fungal diversity present on artificial reefs in an understudied region, the north-central Gulf of Mexico.


2021 ◽  
Vol 9 ◽  
Author(s):  
Ying Zhang ◽  
Hongyu Cao ◽  
Peishan Zhao ◽  
Xiaoshuai Wei ◽  
Guodong Ding ◽  
...  

Revegetation is regarded as an effective means to improve the ecological environment in deserts and profoundly influences the potential ecological functions of the soil fungal community. Therefore, Illumina high-throughput sequencing was performed to characterize the soil fungal diversity and community composition at two soil depths (0–10 cm and 10–20 cm) with four revegetation durations (natural grassland, half-mature, nearly mature, and mature Pinus. sylvestris var. mongolica plantations) in the Mu Us Sandy Land, China. The effects of soil properties on soil fungal communities were also examined to reveal the connection between fungal function and soil environment. The results indicated that 1) soil nutrient content and enzyme activity showed significant differences through the restoration durations, 2) there was no significant effect of soil depth on soil fungal diversity, while the Shannon diversity index of all fungal communities was significantly different among different revegetation durations, 3) compared with grassland, ectomycorrhizal fungi (notably, Inocybe, Tuber, and Calostoma) were abundant in plantations. The endophyte fungus Mortierella was among the top 10 genera in all soil samples and arbuscular mycorrhizal fungus Diversispora was the indicator genus of the grassland, and 4) catalase and total nitrogen were the main factors affecting fungal community composition and were closely related to saprotrophs and pathotrophs, respectively. This new information indicates the variation of soil fungal communities along revegetation durations and highlights the interaction between fungal functions and desert ecosystems.


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