Sebacinoids within rhizospheric fungal communities associated with subsistence farming in the Congo Basin: a needle in each haystack

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
Jolien Venneman ◽  
Caroline De Tender ◽  
Jane Debode ◽  
Kris Audenaert ◽  
Geert Baert ◽  
...  

ABSTRACT The unique ecosystem of the Congolese rainforest has only scarcely been explored for its plant–fungal interactions. Here, we characterized the root fungal communities of field-grown maize and of Panicum from adjacent borders in the Congo Basin and assessed parameters that could shape them. The soil properties indicated that comparable poor soil conditions prevailed in fields and borders, illustrating the low input character of local subsistence farming. The rhizosphere fungal communities, dominated by ascomycetous members, were structured by plant species, slash-and-burn practices and soil P, pH and C/N ratio. Examining fungi with potential plant growth-promoting abilities, the glomeromycotan communities appeared to be affected by the same parameters, whereas the inconspicuous symbionts of the order Sebacinales seemed less susceptible to environmental and anthropogenic factors. Notwithstanding the low abundances at which they were detected, sebacinoids occurred in 87% of the field samples, implying that they represent a consistent taxon within indigenous fungal populations across smallholder farm sites. Pending further insight into their ecosystem functionality, these data suggest that Sebacinales are robust root inhabitants that might be relevant for on-farm inoculum development within sustainable soil fertility management in the Sub-Saharan region.

2020 ◽  
Vol 96 (11) ◽  
Author(s):  
María Isabel Mujica ◽  
María Fernanda Pérez ◽  
Marcin Jakalski ◽  
Florent Martos ◽  
Marc André Selosse

ABSTRACT Little is known about the soil factors influencing root-associated fungal communities in Orchidaceae. Limited evidence suggests that soil nutrients may modulate the association with orchid mycorrhizal fungi (OMF), but their influence on non-mycorrhizal fungi remains unexplored. To study how nutrient availability affects mycorrhizal and non-mycorrhizal fungi associated with the orchid Bipinnula fimbriata, we conducted a metagenomic investigation within a large population with variable soil conditions. Additionally, we tested the effect of phosphorus (P) addition on fungal communities and mycorrhizal colonization. Soil P negatively correlated with the abundance of OMF, but not with the abundance of non-mycorrhizal fungi. After fertilization, increments in soil P negatively affected mycorrhizal colonization; however, they had no effect on OMF richness or composition. The abundance and richness of pathotrophs were negatively related to mycorrhizal colonization and then, after fertilization, the decrease in mycorrhizal colonization correlated with an increase in pathogen richness. Our results suggest that OMF are affected by soil conditions differently from non-mycorrhizal fungi. Bipinnula fimbriata responds to fertilization by altering mycorrhizal colonization rather than by switching OMF partners in the short term, and the influence of nutrients on OMF is coupled with indirect effects on the whole fungal community and potentially on plant's health.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Jean Trap ◽  
Patricia Mahafaka Ranoarisoa ◽  
Usman Irshad ◽  
Claude Plassard

Plants evolve complex interactions with diverse soil mutualist organisms to enhance P mobilization from the soil. These strategies are particularly important when P is poorly available. It is still unclear how the soil P source (e.g., mineral P versus recalcitrant organic P) and its mobility in the soil (high or low) affect soil mutualist biological (ectomycorrhizal fungi, bacteria and bacterial-feeding nematodes) richness—plant P acquisition relationships. Using a set of six microcosm experiments conducted in growth chamber across contrasting P situations, we tested the hypothesis that the relationship between the increasing addition of soil mutualist organisms in the rhizosphere of the plant and plant P acquisition depends on P source and mobility. The highest correlation (R2 = 0.70) between plant P acquisition with soil rhizosphere biological richness was found in a high P-sorbing soil amended with an organic P source. In the five other situations, the relationships became significant either in soil conditions, with or without mineral P addition, or when the P source was supplied as organic P in the absence of soil, although with a low correlation coefficient (0.09 < R2 < 0.15). We thus encourage the systematic and careful consideration of the form and mobility of P in the experimental trials that aim to assess the role of biological complexity on plant P nutrition.


2021 ◽  
Author(s):  
Rasmus Kjoller ◽  
Carla Cruz-Paredes

&lt;p&gt;Soil pH is consistently recorded as the single most important variable explaining bacterial richness and community composition locally as globally. Bacterial richness responds to soil pH in a bell-shaped pattern, highest in soils with near-neutral pH, while lower diversity is found in soil with pH &gt;8 and &lt;4.5. Also, community turnover is strongly determined by pH for bacteria. In contrast, pH effects on fungi is apparently less pronounced though also much less studied compared to bacteria. Still, pH appears to be a significant determinant for fungal communities but typically not the most important. Rarely are bacterial and fungal communities co-analyzed from the same field samples taken across pH gradients. Here we analyze the community responses of fungi and bacteria in parallel over an extreme pH gradient ranging from pH 4 to 8 established by applying strongly alkaline wood ash to replicated plots in a Picea abies plantation. Bacterial and fungal community composition were assessed by amplicon-based meta-barcoding. Bacterial richness were not significantly affected by pH, while fungal richness and a-diversity were stimulated with higher pH. We found that both, bacterial and fungal communities increasingly deviated from the untreated plots with increasing amount of wood ash though fungal communities were more resistant to changes than bacterial. Soil NH&lt;sub&gt;4&lt;/sub&gt;, NO&lt;sub&gt;3&lt;/sub&gt; and pH significantly correlated with the NMDS pattern for both bacterial and fungal communities. In the presentation we will discuss resistance versus sensitivity of different fungal functional guilds towards higher pH as well as the underlying factors explaining the community changes.&lt;/p&gt;


2019 ◽  
Author(s):  
Di Liu ◽  
Qinglin Chen ◽  
Pangzhen Zhang ◽  
Deli Chen ◽  
Kate S. Howell

AbstractThe flavours of foods and beverages are formed by the agricultural environment where the plants are grown. In the case of wine, the location and environmental features of the vineyard site imprint the wine with distinctive aromas and flavours. Microbial growth and metabolism play an integral role in wine production from the vineyard to the winery, by influencing grapevine health, wine fermentation, and the flavour, aroma and quality of finished wines. The mechanism by which microbial distribution patterns drive wine metabolites is unclear and while flavour has been correlated with bacterial composition for red wines, bacterial activity provides a minor biochemical conversion in wine fermentation. Here, we collected samples across six distinct winegrowing areas in southern Australia to investigate regional distribution patterns of both fungi and bacteria and how this corresponds with wine aroma compounds. Results show that soil and must microbiota distinguish winegrowing regions and are related to wine chemical profiles. We found a strong relationship between microbial and wine metabolic profiles, and this relationship was maintained despite differing abiotic drivers (soil properties and weather/ climatic measures). Notably, fungal communities played the principal role in shaping wine aroma profiles and regional distinctiveness. We found that the soil microbiome is a potential source of grape- and must-associated fungi, and therefore the weather and soil conditions could influence the wine characteristics via shaping the soil fungal community compositions. Our study describes a comprehensive scenario of wine microbial biogeography in which microbial diversity responds to surrounding environments and ultimately sculpts wine aromatic characteristics. These findings provide perspectives for thoughtful human practices to optimise food and beverage flavour and composition through understanding of fungal activity and abundance.


Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 453
Author(s):  
Yanjiao Liu ◽  
Xiangzhen Li ◽  
Yongping Kou

Ectomycorrhizal fungi (EcMF) are involved in soil nutrient cycling in forest ecosystems. These fungi can promote the uptake of nutrients (e.g., nitrogen (N) and phosphorus (P)) and water by host plants, as well as facilitate host plant growth and resistance to stresses and diseases, thereby maintaining the aboveground primary productivity of forest ecosystems. Moreover, EcMF can acquire the carbon (C) sources needed for their growth from the host plants. The nutrient regulation mechanisms of EcMF mainly include the decay of soil organic matter via enzymatic degradation, nonenzymatic mechanism (Fenton chemistry), and priming effects, which in turn promote C and N cycling. At the same time, EcMF can secrete organic acids and phosphatases to improve the availability of soil P, or increase mycelium inputs to facilitate plant acquisition of P. The spatiotemporal distribution of EcMF is influenced by a combination of historical factors and contemporary environmental factors. The community of EcMF is associated with various factors, such as climate change, soil conditions, and host distribution. Under global climate change, investigating the relationships between the nutrient cycling functions of EcMF communities and their distribution patterns under various spatiotemporal scales is conducive to more accurate assessments of the ecological effects of EcMF on the sustainable development of forest.


2014 ◽  
Vol 65 (6) ◽  
pp. 556 ◽  
Author(s):  
Richard J. Simpson ◽  
Alan E. Richardson ◽  
Shirley N. Nichols ◽  
James R. Crush

Phosphorus (P) fertilisers are important for productivity in many grassland systems. Phosphorus is a non-renewable and finite resource, and there are environmental and economic reasons for using P more effectively. We review the P balance of temperate pastures to identify the factors contributing to inefficient use of P fertiliser and discuss ways to improve P-balance efficiency. Immediate gains can be made by ensuring that P fertiliser inputs are managed to ensure that the plant-available P concentrations of soil do not exceed the minimum concentration associated with maximum pasture production. Unnecessarily high soil P concentrations are associated with greater potential for P loss to the wider environment, and with higher rates of P accumulation in soils that have a high P-sorption capacity. Soil microorganisms already play a crucial role in P cycling and its availability for pasture growth, but are not amenable to management. Consequently, plants with lower critical P requirements, particularly because of better root foraging, will be an important avenue for improving the P-balance efficiency of fertilised pastures. Traits such as long fine roots, branching, root hairs, and mycorrhizal associations all contribute to improved root foraging by pasture plants; some of these traits are amenable to breeding. However, progress in breeding for improved P efficiency in pasture plants has been minimal. It is likely that traditional plant breeding, augmented by marker-assisted selection and interspecific hybridisation, will be necessary for progress. There are practical limits to the gains that can be made by root foraging alone; therefore, plants that can ‘mine’ sparingly available P in soils by producing organic anions and phosphatases are also needed, as are innovations in fertiliser technology.


2020 ◽  
Vol 5 (86) ◽  
pp. 3-10
Author(s):  
V.G. Chernikov ◽  
◽  
R.A. Rostovtsev ◽  
N.A. Kudryavtsev ◽  
I.V. Uschapovsky ◽  
...  

The formation of fiber flax yield and quality parameters depends on many soil-climatic, breedinggenetic, as well as anthropogenic factors. The quality of flax fiber is a combination of a number of features and properties that depend on the varietal characteristics of plants, the conditions of their cultivation, technologies for harvesting and straw retting, as well as on the processing modes of raw materials. During plant vegetation (90-130 days) many factors such as soil conditions (pH 4.8-5.5, humus 1.8-2.5%, P2O5 and K2O – 150-200 and 100-200 mg/kg, respectively) and the area of plant nutrition (15-30 million seeds/ha), temperature regime (the sum of active temperatures 1000-1800ºC), water supplying (400-430 units of water mass to create 1 unit of dry matter) and insolation (the arrival of FAR during the growing season 20-25 kcal / cm²), contamination of weeds (more than 60 annual and perennial species) and pests (more than 200 types of fungal, bacterial and viral diseases), features of phytosanitary measures (more than 50 chemicals) and agrotechnologic manners (Federal Register of technologies for the production of crop products) have a great influence on the quality of flax raw materials and can be a limit factor. Environmentally hazardous pollution of air, water and soil - the main components for the production of fiber flax – strongly affects the yield and quality of flax products. The development of waste-free environmentally friendly technologies for the cultivation, harvesting and processing of flax is an urgent task of scientific support of the industry. The main environmental factors affecting the yield and quality of fiber flax are discussed in the article.


2015 ◽  
Vol 51 (3) ◽  
pp. 370-381 ◽  
Author(s):  
ANNY RUTH PAME ◽  
CHRISTINE KREYE ◽  
DAVID JOHNSON ◽  
SIGRID HEUER ◽  
MATHIAS BECKER

SUMMARYSeedling vigor is important to help ensure good crop establishment. In direct-seeded rice, this is particularly relevant when soil conditions are marginal. In Asia, about one third of the area of rainfed rice is situated on unfavorable soils, many of which are low in plant available P. In such environments, as farmers tend to have few resources, options to overcome poor crop establishment should be low cost and preferably seed-based. The P content of seed depends on genotype and can be augmented by soaking seeds in a P-containing solution prior to seeding (P-priming). In addition, the presence of the Pup1 quantitative trait locus can reportedly confer tolerance to low soil P availability. We tested combinations of seed priming (unprimed control, water priming, P-priming), and inherent seed P concentrations in contrasting rice genotypes (DJ123, Sadri Tor Misri), and two near isogenic sister lines of IR74 with (+Pup1) and without (−Pup1) the Pup1 QTL. Treatment effects on germination were studied in Petri dishes, while seedling growth and P accumulation were assessed using pots with P deficient soil. Germination was less than 75% in seeds with low seed P content. Seed priming with both water and P enhanced germination and seedling growth. In plants growing from high P seeds, water priming outperformed P-priming. In Sadri Tor Misri with low seed P, we observed a tendency for better performance in some parameters when P-primed. While the presence of the Pup1 QTL in IR74 increased shoot biomass and total root length, these effects could be further enhanced by water priming. Combining genetic and seed management approaches may contribute to improved rice establishment in P deficient soils but its effectiveness depends on genotype and seed attributes.


Author(s):  
E. P. Bessolitsyna ◽  

Landscape-ecological analysis of taxonomic diversity and structure of soil invertebrates’ community in the geosystems of the Hamar-Daban Region was carried out on the main levels: local (biogeocenotic), topological (facies) and regional. The paper considers regularities of transformation of communities’ structure in landscape-zonal range under the influence of natural conditions: phytocenotic (peculiarities of vegetation), edaphical and climatic (hydrothermal regime of the soil) and anthropogenic factors. On the models groups: Сarabidae, Staphylinidae, Elateridae, Formicidae altitudinal changes of community' structure have been traced; in all landscape-high-rise complexes (in species composition and abundance of species) was revealed forest preference. The main trend of changes in taxonomic diversity of invertebrate’s communities is a decrease in the species number in the gradient of an increase of climate aridity, and strengthening of the hypothermal character and anthropogenic pressure. Peculiarities of structures invertebrate’s communities and their changes due to the climate change and anthropogenic impacts can serve as one of diagnostic criteria of soil conditions and can be used for estimation of landscapes’ transformation and monitoring.


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