Taxonomy and phylogeny of the glomales, S. Rosendahl et al biodiversity and characterization of arbuscular mycorrhizal fungi at the molecular level, D. van Tuinen et al characterization of arbuscular mycorrhizal fungi by immunochemical methods, A. Hahn et al European bank of glomales - an essential tool for the efficient international and interdisciplinary collaboration, J.C. Dodd et al physiological characteristics of the host plant promoting an undisturbed functioning of the mycorrhizal symbiosis, C. Azcon-Aguilar and B. Bago recognition and infection process, basis for host specificity of arbuscular mycorrhizal fungi, M. Giovannetti et al ultrastructural analysis reveals the complex interactions between root cells and arbuscular mycorrhizal fungi, P. Bonfante impact of mycorrhizal colonization on root architecture, root longevity and the formation of growth regulators, D. Atkinson et al biogeochemical cycling and arbuscular mycorrhizas in the sustainability of plant-soil systems, P. Jeffries and J.M. Barea arbuscular mycorrhizas and agrosystem stability, G.J. Bethlenfalvay and H. Schuepp hyphal phosphorous transport - a keystone to mycorrhizal enhancement of plant growth, I. Jakobsen et al approaches to the study of the extraradical mycelium of arbuscular mycorrhizal fungi, J.C. Dodd water relations and alleviation of drought stress in mycorrhizal plants, M. Sanchez-Diaz and M. Honrubia impact of arbuscular mycorrhizal fungi on plant uptake of heavy metals and radionuclides from soil, K. Haselwandter et al biocontrol of plant pathogens using arbuscular mycorrhizal fungi, J.E. Hooker et al management of positive interactions of arbuscular mycorrhizal fungi with essential groups of soil microorganisms, G. Puppi et al micropropagated plants, an opportunity to positively manage mycorrhizal activities, M. Vestberg and V. Estaun.

Impact of Arbuscular Mycorrhizas on Sustainable Agriculture and Natural Ecosystems

In many soils, roots and fungal hyphae, especially those of vesicular arbuscular mycorrhizal (VAM) fungi, stabilize macroaggregates (>250 μm diameter); organic residues, bacteria, polysaccharides and inorganic materials stabilize microaggregates (<250 μm). This review discusses the factors (including other organisms) which affect VAM hyphae and their extracellular polysaccharides in soil, and the subsequent effect on stability of aggregates. The review also discusses the possible role of other organisms, including ectomycorrhizal fungi, in the stability of soil, and suggests future research.

Possible role of soil microorganisms in aggregation in soils

Arbuscular mycorrhizal (AM) fungi are ubiquitous in agricultural soils. These fungi play important roles in plant nutrition and soil conservation. The persistence of AM fungi in ecosystems depends on the formation and survival of propagules (e.g., spore, hyphae and colonized roots). While spores are considered to be resistant structure that may be view as “long-term” propagules when viable host plants are not present, hyphae are considered to be the main source of inocula when host plants are present and the soil is not disturbed. Tillage is an integral part of modern agriculture that can modify the physical, chemical and biological properties of a soil. Consequently, tillage practices may also affect AM fungi. The various tillage practices used in the management of soil for maximum crop production may negatively impact the survival of AM fungal propagules. In tilled soil, certain AM species may survive while others may disappear. Because AM fungi are more abundant in the topsoil, deep plowing may dilute ...

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Tillage or no-tillage: Impact on mycorrhizae

The potential contribution of plant growth-promoting bacteria to reduce environmental degradation – A comprehensive evaluation

Arbuscular-mycorrhizal (AM) fungi stabilize the soil and enhance plant growth by alleviating nutrient and drought stress. Their contributions to agriculture are well known, but their role in desert ecosystems has received less attention. The AM status of perennial plants in disturbed and undisturbed plots were investigated in the Sonoran Desert near La Paz, Baja California Sur, Mexico to determine if AM fungi contribute to resource-island stability and plant establishment. All perennial plants (46 species) in the study plots were AM, but root colonization varied widely ( 70%). Roots of plants that established in greatest numbers in plant-free zones (colonizers) of disturbed areas were highly AM. Plants with trace ( 20 yr) nurse-legumes P. articulata and O. tesota supported the largest number of under-story plants. Younger plants had only occasional associates. AM propagule densities in plant-free areas were lower than under plant canopies (40 vs. 280 propagules/kg soil). Occurrence of soil mounds (islands) under plants owing to soil deposition was related to the nature of the canopies and to the AM status of the roots. Island soils were enmeshed with AM-fungal hyphae, especially in the upper layer (approximately 10 cm). Seedlings of P. pringlei, growing in a screenhouse for six months in soil collected under P. articulata, had a biomass ten times greater than plants growing in bare-area soil. The results are consistent with the proposition that AM fungi contributed to the plant-soil system of our study area by: (1) helping to stabilize windborne soil that settles under dense plant canopies; (2) enhancing the establishment of colonizer plants in bare soils of disturbed areas; and (3) influencing plant associations through differences in the mycotrophic status of the associates.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1526-100X.1999.72027.x

S. B. Camel

Papers

Growth of Vesicular-Arbuscular Mycorrhizal Mycelium through Bulk Soil