scholarly journals Belowground fungal community diversity, composition and ecological functionality associated with winter wheat in conventional and organic agricultural systems

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9732
Author(s):  
Sigisfredo Garnica ◽  
Ronja Rosenstein ◽  
Max Emil Schön

Understanding the impacts of agricultural practices on belowground fungal communities is crucial in order to preserve biological diversity in agricultural soils and enhance their role in agroecosystem functioning. Although fungal communities are widely distributed, relatively few studies have correlated agricultural production practices. We investigated the diversity, composition and ecological functionality of fungal communities in roots of winter wheat (Triticum aestivum) growing in conventional and organic farming systems. Direct and nested polymerase chain reaction (PCR) amplifications spanning the internal transcribed spacer (ITS) region of the rDNA from pooled fine root samples were performed with two different sets of fungal specific primers. Fungal identification was carried out through similarity searches against validated reference sequences (RefSeq). The R package ‘picante’ and FUNGuild were used to analyse fungal community composition and trophic mode, respectively. Either by direct or cloning sequencing, 130 complete ITS sequences were clustered into 39 operational taxonomic units (OTUs) (25 singletons), belonging to the Ascomycota (24), the Basidiomycota (14) and to the Glomeromycota (1). Fungal communities from conventional farming sites are phylogenetically more related than expected by chance. Constrained ordination analysis identified total N, total S and Pcal that had a significant effect on the OTU’s abundance and distribution, and a further correlation with the diversity of the co-occurring vegetation could be hypothesised. The functional predictions based on FUNGuild suggested that conventional farming increased the presence of plant pathogenic fungi compared with organic farming. Based on diversity, OTU distribution, nutrition mode and the significant phylogenetic clustering of fungal communities, this study shows that fungal communities differ across sampling sites, depending on agricultural practices. Although it is not fully clear which factors determine the fungal communities, our findings suggest that organic farming systems have a positive effect on fungal communities in winter wheat crops.

2003 ◽  
Vol 54 (9) ◽  
pp. 889 ◽  
Author(s):  
J. L. Kitchen ◽  
G. K. McDonald ◽  
K. W. Shepherd ◽  
M. F. Lorimer ◽  
R. D. Graham

Organic farming standards do not allow addition of water-soluble fertilisers and therefore it is likely that growth of organically grown crops will be limited by nutrient availability. However, in marginal rainfall conditions, when growth in conventional systems is limited by water availability, yields of organically grown crops could be comparable with those conventionally grown. Similarly, micronutrient-efficient plant varieties could be expected to perform comparatively better under organic farming conditions than they do in conventional systems, when compared with micronutrient-inefficient varieties.In this study, biomass and grain production of wheat from certified organic farming systems were compared with neighbouring conventional farming systems in 'across the fence' field trials in 1 moderate and 2 marginal rainfall areas of South Australia. Wheat varieties compared included 2 old wheat varieties developed under relatively low-input conditions (Baroota Wonder and Dirk-48) and varieties shown to be micronutrient-efficient (Janz and Trident) and inefficient (Yallaroi).The organic farming systems produced significantly less biomass than the conventional farming systems at late tillering in both the moderate and marginal rainfall areas. Grain yield was variable, but significantly lower in the organic farming system for 11 of the 14 comparisons. None of the varieties showed an adaptive advantage for 1 farming system over the other. The relative yield of the organic system, compared with the conventional system, was not associated with rainfall.


2021 ◽  
Vol 12 ◽  
Author(s):  
Aitana Ares ◽  
Joana Costa ◽  
Carolina Joaquim ◽  
Duarte Pintado ◽  
Daniela Santos ◽  
...  

Maize is one of the most important crops worldwide and is the number one arable crop in Portugal. A transition from the conventional farming system to organic agriculture requires optimization of cultivars and management, the interaction of plant–soil rhizosphere microbiota being pivotal. The objectives of this study were to unravel the effect of population genotype and farming system on microbial communities in the rhizosphere of maize. Rhizosphere soil samples of two open-pollinated maize populations (“SinPre” and “Pigarro”) cultivated under conventional and organic farming systems were taken during flowering and analyzed by next-generation sequencing (NGS). Phenological data were collected from the replicated field trial. A total of 266 fungi and 317 bacteria genera were identified in “SinPre” and “Pigarro” populations, of which 186 (69.9%) and 277 (87.4%) were shared among them. The microbiota of “Pigarro” showed a significant higher (P < 0.05) average abundance than the microbiota of “SinPre.” The farming system had a statistically significant impact (P < 0.05) on the soil rhizosphere microbiota, and several fungal and bacterial taxa were found to be farming system-specific. The rhizosphere microbiota diversity in the organic farming system was higher than that in the conventional system for both varieties. The presence of arbuscular mycorrhizae (Glomeromycota) was mainly detected in the microbiota of the “SinPre” population under the organic farming systems and very rare under conventional systems. A detailed metagenome function prediction was performed. At the fungal level, pathotroph–saprotroph and pathotroph–symbiotroph lifestyles were modified by the farming system. For bacterial microbiota, the main functions altered by the farming system were membrane transport, transcription, translation, cell motility, and signal transduction. This study allowed identifying groups of microorganisms known for their role as plant growth-promoting rhizobacteria (PGPR) and with the capacity to improve crop tolerance for stress conditions, allowing to minimize the use of synthetic fertilizers and pesticides. Arbuscular mycorrhizae (phyla Glomeromycota) were among the most important functional groups in the fungal microbiota and Achromobacter, Burkholderia, Erwinia, Lysinibacillus, Paenibacillus, Pseudomonas, and Stenotrophomonas in the bacterial microbiota. In this perspective, the potential role of these microorganisms will be explored in future research.


2010 ◽  
Vol 149 (1) ◽  
pp. 85-93 ◽  
Author(s):  
D. N. VLACHOSTERGIOS ◽  
A. S. LITHOURGIDIS ◽  
D. G. ROUPAKIAS

SUMMARYThe development of organic agriculture has raised the demand for crop varieties well-adapted to organic farming systems. Most of the varieties presently cultivated in organic agriculture were developed from conventional breeding programmes. The objective of the present work was to study the adaptability to organic farming systems of lentil (Lens culinaris Medik.) varieties developed from conventional breeding programmes. Twenty varieties were evaluated over five environments under organic and conventional farming systems from 2005 to 2007. Genotype×system interactions (GSI) for grain yield were significantly different in four out of the five environments and GSI explained 0·03–0·17 of the variance. Spearman's rank correlation index of the 20 varieties between the conventional and organic system ranged from 0·27 to 0·93 in the five environments. Direct selection of the top five varieties in organic systems resulted in significantly higher grain yields than indirect selection in one out of the five environments. However, among the top five varieties, the highest yielding varieties under conventional farming systems were not always the highest yielding varieties under organic farming systems. These results indicate that the demands of organic agriculture for yield performance could be only partially satisfied by varieties developed under conventional breeding programmes.


2011 ◽  
Vol 14 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Hiroshi Uchino ◽  
Kazuto Iwama ◽  
Yutaka Jitsuyama ◽  
Keiko Ichiyama ◽  
Eri Sugiura ◽  
...  

2006 ◽  
Vol 18 ◽  
pp. 301-308 ◽  
Author(s):  
E.A. Stockdale ◽  
M.A. Shepherd ◽  
S. Fortune ◽  
S.P. Cuttle

2021 ◽  
pp. 116827
Author(s):  
Violette Geissen ◽  
Vera Silva ◽  
Esperanza Huerta Lwanga ◽  
Nicolas Beriot ◽  
Klaas Oostindie ◽  
...  

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