scholarly journals Zero Tillage Systems Conserve Arbuscular Mycorrhizal Fungi, Enhancing Soil Glomalin and Water Stable Aggregates with Implications for Soil Stability

Soil Systems ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Thomas I. Wilkes ◽  
Douglas J. Warner ◽  
Veronica Edmonds-Brown ◽  
Keith G. Davies ◽  
Ian Denholm
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Conventional Tillage ◽  
Zero Tillage ◽  
Tillage Systems ◽  
Symbiotic Relationships ◽  
Structural Support ◽  
Water Stable Aggregates ◽  
Seedbed Preparation

Arbuscular Mycorrhizal (AM) fungi form mutualistic symbiotic relationships with approximately 80% of terrestrial plant species, while producing the glycoprotein glomalin as a structural support molecule along their mycelial network. Glomalin confers two benefits for soils: (1) acting as a carbon and nitrogen storage molecule; (2) the binding of soil microaggregates (<250 µm) to form larger, more stable structures. The present study aimed to test the hypothesis that a correlation between glomalin and soil aggregation exists and that this is influenced by the method of seedbed preparation. The soils from two crops of winter wheat in Hertfordshire, UK, practising either conventional (20 cm soil inversion) or zero tillage exclusively, were sampled in a 50 m grid arrangement over a 12 month period. Glomalin and water stable aggregates (WSA) were quantified for each soil sample and found to be significantly greater in zero tillage soils compared to those of conventional tillage. A stronger correlation between WSA and glomalin was observed in zero tillage (Pearson’s coeffect 0.85) throughout the cropping year compared to conventional tillage (Pearson’s coeffect 0.07). The present study was able to conclude that zero tillage systems are beneficial for AM fungi, the enhancement of soil glomalin and soil erosion mitigation.

scholarly journals Influence on Different Types of Mycorrhizal Fungi on Crop Productivity in Ecosystem

2015 ◽  
Vol 38 ◽  
pp. 9-15 ◽  
Author(s):  
K. Ramakrishnan ◽  
G. Bhuvaneswari
Keyword(s):  
Mycorrhizal Fungi ◽  
Current Knowledge ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Heavy Metal Stress ◽  
Crop Productivity ◽  
Symbiotic Relationships ◽  
Potential Benefits ◽  
Mycorrhizal Interactions

Mycorrhizal fungi greatly enhanced the ability of plants to take up phosphorus and other nutrients those are relatively immobile and exist in low concentration in the soil solution. Fungi can be important in the uptake of other nutrients by the host plant. Mycorrhizae establish symbiotic relationships with plants and play an essential role in plant growth, disease protection, and overall soil quality. Of the seven types of mycorrhizae described in current scientific literature (arbuscular, ecto, ectendo, arbutoid, monotropoid, ericoid and orchidaceous mycorrhizae), the arbuscular and ectomycorrhizae are the most abundant and widespread. This chapter presents an overview of current knowledge of mycorrhizal interactions, processes, and potential benefits to society. The molecular basis of nutrient exchange between arbuscular mycorrhizal (AM) fungi and host plants is presented; the role of AM fungi in disease protection, alleviation of heavy metal stress and increasing grain production. Most land plants form associations with mycorrhizal fungi. Mycorrhizas are mutualistic associations between fungi and plant roots. They are described as symbiotic because the fungus receives photo synthetically derived carbon compounds and the plant has increased access to mineral nutrients and sometimes water.

scholarly journals Use of the Signature Fatty Acid 16:1ω5 as a Tool to Determine the Distribution of Arbuscular Mycorrhizal Fungi in Soil

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Ngosong ◽  
Elke Gabriel ◽  
Liliane Ruess
Keyword(s):  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Plant Root ◽  
Background Level ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Biomass Estimation ◽  
Lipid Fatty Acid ◽  
Neutral Lipid Fatty Acid ◽  
Root Symbionts

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.

Soil microbial biomass and diversity respond to tillage and sulphur fertilizers

2001 ◽  
Vol 81 (5) ◽  
pp. 577-589 ◽  
Author(s):  
N. Z. Lupwayi ◽  
M. A. Monreal ◽  
G. W. Clayton ◽  
C. A. Grant ◽  
A. M. Johnston ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Microbial Diversity ◽  
Soil Microorganisms ◽  
Soil Microbial Biomass ◽  
Conventional Tillage ◽  
Bulk Soil ◽  
Zero Tillage ◽  
Negative Effects ◽  
Tillage Systems ◽  
Soil Microbial

There is little information on the effects of S management strategies on soil microorganisms under zero tillage systems o n the North American Prairies. Experiments were conducted to examine the effects of tillage and source and placement of S on soil microbial biomass (substrate induced respiration) and functional diversity (substrate utilization patterns) in a canola-wheat rotation under conventional and zero tillage systems at three sites in Gray Luvisolic and Black Chernozemic soils. Conventional tillage significantly reduced microbial biomass and diversity on an acidic and C-poor Luvisolic soil, but it had mostly no significant effects on the near-neutral, C-rich Luvisolic and Chernozemic soils, which underlines the importance of soil C in maintaining a healthy soil. Sulphur had no significant effects on soil microbial biomass, and its effects on microbial diversity were more frequent on the near-neutral Luvisol, which was more S-deficient, than on the acidic Luvisol or the Chernozem. Significant S effects on microbial diversity were observed both in the bulk soil (negative effects, compared with the control) and rhizosphere (positive effects) of the acidic Luvisol, but all significant effects (positive) were observed in root rhizospheres in the other soils. Sulphur by tillage interactions on acidic Luvisolic soil indicated that the negative effects of S in bulk soil occurred mostly under zero tillage, presumably because the fertilizer is concentrated in a smaller volume of soil than under conventional tillage. Sulphate S effects, either negative or positive, on microbial diversity were usually greater than elemental S effects. Therefore, S application can have direct, deleterious effects on soil microorganisms or indirect, beneficial effects through crop growth, the latter presumably due to increased root exudation in the rhizosphere of healthy crops. Key Words: Biolog, conservation tillage, microbial biodiversity, rhizosphere, soil biological quality, S fertilizer type and placement

scholarly journals Response of Arbuscular Mycorrhizal Fungi to Simulated Climate Changes by Reciprocal Translocation in Tibetan Plateau

2015 ◽  
Vol 43 (2) ◽  
pp. 488-493
Author(s):  
Zhaoyong SHI ◽  
Xubin YIN ◽  
Bede MICKAN ◽  
Fayuan WANG ◽  
Ying ZHANG ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Arbuscular Mycorrhizal Fungi ◽  
Reciprocal Translocation ◽  
Mycorrhizal Fungi ◽  
Climate Changes ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Spore Density ◽  
The Tibetan Plateau ◽  
Colonization Frequency

Arbuscular mycorrhiza (AM) fungi are considered as an important factor in predicting plants and ecosystem responses to climate changes on a global scale. The Tibetan Plateau is the highest region on Earth with abundant natural resources and one of the most sensitive region to climate changes. To evaluate the complex response of arbuscular mycorrhizal fungi colonization and spore density to climate changes, a reciprocal translocation experiment was employed in Tibetan Plateau. The reciprocal translocation of quadrats to AM colonization and spore density were dynamic. Mycorrhizal colonization frequency presented contrary changed trend with elevations of quadrat translocation. Colonization frequency reduced or increased in majority quadrats translocated from low to high or from high to low elevation. Responses of colonization intensity to translocation of quadrats were more sensitive than colonization frequency. Arbuscular colonization showed inconsistent trend in increased or decreased quadrat. Vesicle colonization decreased with changed of quadrat from low to high elevations. However, no significant trend was observed. Although spore density was dynamic with signs of decreasing or increasing in translocated quadrats, the majority enhanced and declined respectively in descent and ascent quadrat treatments. It is crucial to understand the interactions between AM fungi and prairie grasses to accurately predict effects of climate change on these diverse and sensitive ecosystems. This study provided an opportunity for understanding the effect of climate changes on AM fungi.

scholarly journals Synergistic community responses of plants and arbuscular mycorrhizal fungi to extreme droughts in a cold-temperate grassland

2020 ◽  
Author(s):  
Wei Fu ◽  
Baodong Chen ◽  
Matthias Rillig ◽  
Wang Ma ◽  
Chong Xu ◽  
...  
Keyword(s):  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Community Dynamics ◽  
Environmental Changes ◽  
Environmental Filtering ◽  
Climate Extremes ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Temperate Grassland ◽  
Community Responses

Mutualistic associations between plants and arbuscular mycorrhizal (AM) fungi may have profound influences on their response to climate changes. Existing theories evaluate the effects of interdependency and environmental filtering on plant-AM fungal community dynamics separately; however, abrupt environmental changes such as climate extremes can provoke duo-impacts on the metacommunity simultaneously. Here, we experimentally tested the relevance of plant and AM fungal community responses to extreme drought (chronic or intense) in a cold temperate grassland. Irrespective of drought intensities, plant species richness and productivity responses were significantly and positively correlated with AM fungal richness and also served as best predictors of AM fungal community shifts. Notably, the robustness of this community synergism increased with drought intensity, likely reflecting increased community interdependence. Network analysis showed a key role of Glomerales in AM fungal interaction with plants, suggesting specific plant-AM fungal pairing. Thus, community interdependence may underpin climate change impact on plant-AM fungal diversity patterns in grasslands.

scholarly journals The Synergy of Arbuscular Mycorrhizal Fungi and Exogenous Abscisic Acid Benefits Robinia pseudoacacia L. Growth through Altering the Distribution of Zn and Endogenous Abscisic Acid

2021 ◽  
Vol 7 (8) ◽  
pp. 671
Author(s):  
Xiao Lou ◽  
Xiangyu Zhang ◽  
Yu Zhang ◽  
Ming Tang
Keyword(s):  
Abscisic Acid ◽  
Mycorrhizal Fungi ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Am Symbiosis ◽  
Antioxidant Defense Systems ◽  
Robinia Pseudoacacia L ◽  
Zn Stress

The simultaneous effects of arbuscular mycorrhizal (AM) fungi and abscisic acid (ABA) on the tolerance of plants to heavy metal (HM) remain unclear. A pot experiment was carried out to clarify the effects of simultaneous applications of AM fungi and ABA on plant growth, Zn accumulation, endogenous ABA contents, proline metabolism, and the oxidative injury of black locust (Robinia pseudoacacia L.) exposed to excess Zn stress. The results suggested that exogenously applied ABA positively enhanced AM colonization, and that the growth of plants only with AM fungi was improved by ABA application. Under Zn stress, AM inoculation and ABA application increased the ABA content in the root/leaf (increased by 48–172% and 92%, respectively) and Zn content in the root/shoot (increased by 63–152% and 61%, respectively) in AM plants, but no similar trends were observed in NM plants. Additionally, exogenous ABA addition increased the proline contents of NM roots concomitantly with the activities of the related synthases, whereas it reduced the proline contents and the activity of Δ1-pyrroline-5-carboxylate synthetase in AM roots. Under Zn stress, AM inoculation and ABA application decreased H2O2 contents and the production rate of O2, to varying degrees. Furthermore, in the roots exposed to Zn stress, AM inoculation augmented the activities of SOD, CAT, POD and APX, and exogenously applied ABA increased the activities of SOD and POD. Overall, AM inoculation combined with ABA application might be beneficial to the survival of black locust under Zn stress by improving AM symbiosis, inhibiting the transport of Zn from the roots to the shoots, increasing the distribution of ABA in roots, and stimulating antioxidant defense systems.

scholarly journals Biocontrol of Sclerotium rolfsii in Groundnut by Using Microbial Inoculants

2017 ◽  
Vol 9 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Khirood DOLEY ◽  
Mayura DUDHANE ◽  
Mahesh BORDE
Keyword(s):  
Mycorrhizal Fungi ◽  
Antioxidant Activities ◽  
Sclerotium Rolfsii ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Stem Rot ◽  
Mycorrhizal Dependency ◽  
Trichoderma Species ◽  
Arachis Hypogaea L ◽  
Microbial Strains

Sclerotium rolfsii (Sacc.) is the causal agent of stem-rot in groundnut (Arachis hypogaea L.)crop. With the increase in demand for the groundnut, control of stem-rot efficiently by microbial strains is fast becoming inevitable as the conventional system of chemicals is degrading our ecosystem. This investigation here emphasizes on inoculation of arbuscular mycorrhizal fungi (AMF) and Trichoderma species for growth achievement and disease control. The present investigation showed that these microbial strains were found to be worth applying as they stimulated growth and decreased harmful effects of S. rolfsii (cv. ‘Western-51’). The increased biochemical parameters and antioxidant activities also indicated their defence related activities in groundnut plants. In spite of positive attributes meted out by these microbial strains towards groundnut crop, the interaction among AM fungi and Trichoderma species seemed to be less co-operative between each other which were noted when mycorrhizal dependency and percent root colonization were observed. However, in summary more practical application of low-input AM fungi along with Trichoderma species may be needed for the advancement of modern agricultural systems.

scholarly journals Haustorium Formation in Medicago truncatula Roots Infected by Phytophthora palmivora Does Not Involve the Common Endosymbiotic Program Shared by Arbuscular Mycorrhizal Fungi and Rhizobia

2015 ◽  
Vol 28 (12) ◽  
pp. 1271-1280 ◽  
Author(s):  
Rik Huisman ◽  
Klaas Bouwmeester ◽  
Marijke Brattinga ◽  
Francine Govers ◽  
Ton Bisseling ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Phytophthora Palmivora ◽  
Living Plant ◽  
Mutualistic Symbiosis ◽  
Membrane Compartment ◽  
Microbe Interactions ◽  
Host Genes

In biotrophic plant-microbe interactions, microbes infect living plant cells, in which they are hosted in a novel membrane compartment, the host-microbe interface. To create a host-microbe interface, arbuscular mycorrhizal (AM) fungi and rhizobia make use of the same endosymbiotic program. It is a long-standing hypothesis that pathogens make use of plant proteins that are dedicated to mutualistic symbiosis to infect plants and form haustoria. In this report, we developed a Phytophthora palmivora pathosystem to study haustorium formation in Medicago truncatula roots. We show that P. palmivora does not require host genes that are essential for symbiotic infection and host-microbe interface formation to infect Medicago roots and form haustoria. Based on these findings, we conclude that P. palmivora does not hijack the ancient intracellular accommodation program used by symbiotic microbes to form a biotrophic host-microbe interface.

Water and bromide movement in a Vertosol under four fallow management systems

Soil Research ◽  
1999 ◽  
Vol 37 (1) ◽  
pp. 75 ◽  
Author(s):  
J. E. Turpin ◽  
J. P. Thompson ◽  
B. J. Bridge ◽  
D. Orange
Keyword(s):  
Water Movement ◽  
Conventional Tillage ◽  
Management Systems ◽  
Zero Tillage ◽  
Tillage Systems ◽  
Fallow Management ◽  
Stubble Retention ◽  
Tracer Solution ◽  
Stubble Burning

Recent work on the Hermitage long-term fallow management found increased rates of anion movement under zero tillage systems compared with conventional tillage. Four separate experiments have been used to determine relative rates of water movement through different fallow management treatments on the Hermitage long-term fallow management trial and the causes of any differences. Photography of the aggregation patterns at the depth of tillage (approx. 15 cm) showed that conventional tillage combined with stubble burning has led to the formation of large massive peds up to 20 cm across below the tillage layer, whereas zero-tillage with stubble retention has maintained much smaller aggregates in this zone. Measurements of hydraulic conductivity at 15 cm under both dry and moist conditions indicated that, when the soil is dry and cracked, all tillage treatments have similar conductivities, but when the soil swells and cracks close, zero tillage–stubble retention maintains a greater volume of large pores and thereby greater conductivity. This effect was further demonstrated when a bromide tracer solution was applied to a relatively wet soil by ring infiltrometer, where only 15% of the solution moved below 15 cm in conventional tillage–stubble burning compared with 26% and 38% in zero tillage{stubble retention. In the final experiment, which followed the movement of surface applied bromide over a 6-month fallow, there were no significant differences in rates of leaching between management treatments.

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