The dynamics of root colonisation by communities of arbuscular mycorrhizal fungi in jarrah forest soil (original) (raw)
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International Agrophysics
Arbuscular mycorrhizal fungi inhabiting soil play an important role for vascular plants. Interaction between arbuscular mycorrhizal fungi, plants and soil microorganisms leads to many mutual advantages. However, the effectiveness of mycorrhizal fungi depends not only on biotic, but also abiotic factors such as physico-chemical properties of the soil, availability of water and biogenic elements, agricultural practices, and climatic conditions. First of all, it is important to adapt the arbuscular mycorrhizal fungi species to changing environmental conditions. The compactness of the soil and its structure have a huge impact on its biological activity. Soil pH reaction has a substantial impact on the mobility of ions in soil dilutions and their uptake by plants and soil microflora. Water excess can be a factor negatively affecting arbuscular mycorrhizal fungi because these microorganisms are sensitive to a lower availability of oxygen. Mechanical cultivation of the soil has a marginal ...
Arbuscular Mycorrhizal Symbiosis, Ecosystem Processes and Environmental Changes in Tropical Soils
Applied Ecology and Environmental Research, 2015
Arbuscular mycorrhizal fungi (AMF) are more widely distributed and associate with a wide range of plant species. AMF are keystone organisms that form an interface between soils and plant roots, and are sensitive to changes in soil and plant conditions. They are important microbial symbioses for plants and under conditions of P-limitation and are significant in the maintenance of soil health and fertility. AMF are crucial for the functioning of terrestrial ecosystems and plants form symbiotic interactions with AMF and colonize more than 80% of plant roots. Mycorrhizal fungi are known to influence plant diversity patterns in a variety of ecosystems globally. AMF hyphae form an extensive network in soil and length is a common parameter used to quantifying fungal hyphae. The mycelial network of AM fungi extends into the soil volume and greatly increases the surface area for uptake of immobile nutrients. Also, AM symbioses improve drought tolerance of plants and enhance tolerance of or resistance to root pathogens. Furthermore, networks of AM hyphae play a role in the formation of stable soil aggregates, building up a macroporous structure of soil that allows penetration of water and air and prevents erosion. The functioning of AMF symbiosis is mediated by direct and indirect effects of biotic and abiotic factors of the surrounding rhizosphere, community, and ecosystem. They have great potential in the restoration of disturbed land and low fertility soil. Little is known about the effects of environmental changes on AMF abundance, activity and the impact on ecosystem services. Also, we still have much to learn regarding the extent of mycorrhizal fungal diversity. It is critical to gain a clearer understanding of functional variation among AM fungal species to guide conservation and restoration efforts.
Introduction: The study of symbiotic relationship between arbuscular mycorrhizal fungi (AMF) and medicinal plants is very important. Information about the symbiosis of medicinal plant species with AMF in the semi-arid regions of Iran is rare. This information allows increasing knowledge of the biology and ecology of these plant species. Materials and methods: The existence of AM symbiosis in 48 medicinal plant species (belonging to 9 families) was studied by root staining. Soil around the root of each species was sampled and analyzed for all soil properties which may be interrelated to AM symbiosis. The importance of different soil properties in AMF and plant biological relationship and the dependency of root colonization and spore formation by AMF on soil properties were statistically analyzed. Results: Among them Lepidium sativum, Brassica oleracea, Cheiranthus cheiri, Beta vulgaris, Spinacia oleracea, Malva sylvestris, Zygophyllum fabago, Arctium Lappa have not been colonized by AM fungi. Colonization and spore density of perennial plants were slightly higher than those of annual plants and were varied among different plant families. Soil texture and available phosphorous were the most important soil properties affecting fungal root colonization and spore numbers. Discussion and conclusion: Although in accordance with other researches, most of the medicinal plants from Brassicaceae family had no mycorrhizal symbiosis, a few of them had this type of symbiosis. Dependency of spore formation by AM fungi on soil properties was higher than dependency of root colonization percentage on soil properties. Increasing root colonization and spore numbers with increasing the percentage of sand and decreasing the percentage of clay and available phosphorous in soils show that plants are more depended on mycorrhizal symbiosis in hard environments and less productive soils. Key words: Arbuscular mycorrhiza, Medicinal plants, Soil properties, Root colonization
Journal of Ecology, 2006
1 Arbuscular mycorrhizal (AM) fungi are obligate root symbionts that are present in most terrestrial ecosystems and have roles in plant mineral nutrition, carbon cycling and biotic interactions. In this work, 26 publications were surveyed that report on the occurrence of natural root-colonizing AM fungi identified using rDNA region sequences. A total of 52 host plant species were investigated. Sixteen publications provided data enabling a comparison to be made of AM fungal taxon richness and community composition across 36 host plant species and 25 locations. Ninety-five fungal taxa (small subunit rRNA gene sequence types) were involved, 49 of which were recorded from at least two study sites, and 65 from more than one host plant species. 2 The number of AM fungal taxa per host plant species differed between habitat types: a significantly higher richness was found in tropical forests (18.2 fungal taxa per plant species), followed by grasslands (8.3), temperate forests (5.6) and habitats under anthropogenic influence (arable fields and polluted sites, 5.2). 3 AM fungal communities exhibit differing compositions in broadly defined habitat types: tropical forests, temperate forests and habitats under anthropogenic influence. Grassland locations around the world host heterogeneous AM fungal communities. 4 A number of AM fungi had a global distribution, including sequence types related to the Glomus intraradices / fasciculatum group, G. mosseae , G . sp. UY1225 and G. hoi , as well as the Glomus and Scutellospora types of unknown taxonomic affiliation. Widespread taxa occur in both natural and anthropogenic (disturbed) habitats, and may show high local abundance. However, about 50% of taxa have been recorded from only a single site. 5 The current global analysis of AM fungal communities suggests that soil microorganisms may exhibit different distribution patterns, resulting in a high variability of taxon richness and composition between particular ecosystems.
Arbuscular mycorrhizal fungi (AMF) are more widely distributed and can associate with a wide range of plant species. AMF are keystone organisms that form an interface between soils and plant roots. They are also sensitive to environmental changes. AMF are important microbial symbioses for plants under conditions of P-limitation. The AMF are crucial for the functioning of terrestrial ecosystems as they form symbiotic interactions with plants. Mycorrhizal fungi are known to influence plant diversity patterns in a variety of ecosystems globally. AMF hyphae form an extensive network in the soil. The length is a common parameter used to quantifying fungal hyphae. The mycelial network of AM fungi extends into the soil volume and greatly increases the surface area for the uptake of immobile nutrients. Also, AM symbioses improve plants tolerance to drought and enhance plants’ tolerance of or resistance to root pathogens. Also, the networks of AM hyphae play a crucial role in the formation of stable soil aggregates and in the building up of a macroporous structure of soil that allows penetration of water and air and thereby prevents erosion. The functioning of AMF symbiosis is mediated by direct and indirect effects of biotic and abiotic factors of the surrounding rhizosphere, the community, and the ecosystem. AMF have great potential in the restoration of disturbed land and low fertility soil. However, despite the importance of AMF to terrestrial ecosystems, little is known about the effects of environmental changes on AMF abundance, activity and the impact of these changes on the ecosystem services. Therefore, it is important to gain a clearer understanding of the effects of environmental changes on the AM fungal species to guide conservation and restoration efforts.
Mycorrhiza, 2020
This study explores the relationships of AM fungal abundance and diversity with biotic (host plant, ungulate grazing) and abiotic (soil properties, precipitation) factors in the Serengeti National Park, Tanzania. Soil and root samples were collected from grazed and ungrazed plots at seven sites across steep soil fertility and precipitation gradients. AM fungal abundance in the soil was estimated from the density of spores and the concentration of a fatty acid biomarker. Diversity of AM fungi in roots and soils was measured using DNA sequencing and spore identification. AM fungal abundance in soil decreased with grazing and precipitation and increased with soil phosphorus. The community composition of AM fungal DNA in roots and soils differed. Root samples had more AM fungal indicator species associated with biotic factors (host plant species and grazing), and soil samples had more indicator species associated with particular sample sites. These findings suggest that regional edaphic conditions shape the sitelevel species pool from which plant species actively select root-colonizing fungal assemblages modified by grazing. Combining multiple measurements of AM fungal abundance and community composition provides the most informed assessment of the structure of mycorrhizal fungal communities in natural ecosystems.
2012
Mycorrhizal association in seven plants grown in Arasbaran forest located in the north west of Iran was investigated. The soil samples were collected from the plants rhizosphere. Physico-chemical properties of rhizosphere soils like soil texture, pH, EC and some extractable nutrients such as N, P and K were recorded. The number of spores in rhizosphere and percentage of root mycorrhizal colonization were found. Soil physico-chemical analyses were done on August while spore number and root colonization were studied in May and August. All the data collected in this research were analyzed by the statistical software, SPSS. Results showed that different plant species colonized differently by VAM fungi, and spore number and root mycorrhizal colonization increased through the time from May to August. Among the physicochemical factors, soil N content had high correlation with root colonization and soil extractable P had high correlation with soil spore number. pH had a high negative correlation with spore number. Among the plant species, Stachys pubescens showed the most VAM fungi root colonization and Cruciata laevipes rhizosphere soil showed the highest spore number.
Arbuscular Mycorrhizal Fungi – Their Life and Function in Ecosystem
Agriculture (Pol'nohospodárstvo), 2019
Arbuscular mycorrhizal fungi living in the soil closely collaborate with plants in their root zone and play very important role in their evolution. Their symbiosis stimulates plant growth and resistance to different environmental stresses. Plant root system, extended by mycelium of arbuscular mycorrhizal fungi, has better capability to reach the water and dissolved nutrients from a much larger volume of soil. This could solve the problem of imminent depletion of phosphate stock, affect plant fertilisation, and contribute to sustainable production of foods, feeds, biofuel, and raw materials. Expanded plant root systems reduce erosion of soil, improve soil quality, and extend the diversity of soil microflora. On the other hand, symbiosis with plants affects species diversity of arbuscular mycorrhizal fungi and increased plant diversity supports diversity of fungi. This review summarizes the importance of arbuscular mycorrhizal fungi in relation to beneficial potential of their symbios...
Ecology, 1998
Almost all natural plant communities contain arbuscular mycorrhizal fungi (AMF). We hypothesized that the species composition of AMF communities could have the potential to determine plant community structure if the growth response to different AMF species or to communities of AMF species varies among plant species. To test the existence of such a differential response we conducted a pot experiment where each of three plant species, Hieracium pilosella, Bromus erectus, and Festuca ovina were inoculated with each of four AMF species, or with a mixture of these four AMF species, or were uninoculated. The AMF species originated from a calcareous grassland in which the three plant species also coexisted.
2009
Arbuscular mycorrhizal fungi (AMF) are important functional components of ecosystems. Although there is accumulating knowledge about AMF diversity in different ecosystems, the effect of forest management on diversity and functional characteristics of AMF communities has not been addressed. Here, we used soil inoculum representing three different AM fungal communities (from a young forest stand, an old forest stand and an arable field) in a greenhouse experiment to investigate their effect on the growth of three plant species with contrasting local distributions -Geum rivale, Trifolium pratense and Hypericum maculatum. AM fungal communities in plant roots were analysed using the terminal restriction fragment length polymorphism (T-RFLP) method. The effect of natural AMF communities from the old and young forest on the growth of studied plant species was similar. However, the AMF community from the contrasting arable ecosystems increased H. maculatum root and shoot biomass compared with forest inocula and T. pratense root biomass compared to sterile control. According to ordination analysis AMF inocula from old and young forest resulted in similar root AMF communities whilst plants grown with AM fungi from arable field hosted a different AMF community from those grown with old forest inocula. AMF richness in plant roots was not related to the origin of AMF inoculum. G. rivale hosted a significantly different AM fungal community to that of T. pratense and H. maculatum. We conclude that although the composition of AM fungal communities in intensively managed stands differed from that of old stands, the ecosystem can still offer the 'symbiotic service' necessary for the restoration of a characteristic old growth understorey plant community.