Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. II. Mycorrhizal fungal communities

1998 ◽  
Vol 76 (2) ◽  
pp. 204-212 ◽  
Author(s):  
Ann B Gould ◽  
James W Hendrix

Over a period of 2.5 years, mycorrhizal fungal communities in soils of five abandoned surface coal mine sites in western Kentucky were studied in relation to time following reclamation. These sites were reclaimed at different times and were in varying stages of revegetation. At the seeding stage of reclamation, low populations of mycorrhizal fungal spores of only a few species, notably Glomus microcarpum Tul. & Tul., Glomus aggregatum Schenck & Smith emend. Koske, and Glomus fasciculatum (Thaxter) Gerdemann & Trappe emend. Walker & Koske, were present. Populations of spores of these species increased rapidly during the first 1 or 2 years after reclamation. Other species, notably those with larger spores, appeared with time. Spores of one group of species were a high proportion of the total early after reclamation, then declined in relation to populations of other species. A second group appeared soon after reclamation and maintained a relatively constant proportion of the total population. A third group was inconspicuous for a few years after reclamation but increased in proportion to the total population of spores with time. Species richness was low soon after reclamation, rose slowly and erratically over 5 years, then stabilized at about 10 species. Species dominance, diversity, and evenness were relatively constant after the first 2 years of reclamation.Key words: Glomales mycorrhizal fungi, arbuscular mycorrhizal fungi, abandoned minespoil, succession, community relations.

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.


2020 ◽  
Author(s):  
Mariah M. McIntosh ◽  
Lorinda Bullington ◽  
Ylva Lekberg ◽  
Lila Fishman

SUMMARYUnderstanding the physiological and genetic mechanisms underlying plant variation in interactions with root-associated biota (RAB) requires a micro-evolutionary approach. We use locally adapted montane annual and coastal perennial ecotypes of Mimulus guttatus (yellow monkeyflower) to examine population-scale differences in plant-RAB-soil feedbacks.We characterized fungal communities for the two ecotypes in-situ and used a full-factorial greenhouse experiment to investigate the effects of plant ecotype, RAB source, and soil origin on plant performance and endophytic root fungal communities.The two ecotypes harbored different fungal communities and responsiveness to soil biota was highly context-dependent. Soil origin, RAB source, and plant ecotype all affected the intensity of biotic feedbacks on plant performance. Feedbacks were primarily negative, and we saw little evidence of local adaptation to either soils or RAB. Both RAB source and soil origin significantly shaped fungal communities in roots of experimental plants. Further, the perennial ecotype was more colonized by arbuscular mycorrhizal fungi (AMF) than the montane ecotype, and preferentially recruited home AMF taxa.Our results suggest life history divergence and distinct edaphic habitats shape plant responsiveness to RAB and influence specific associations with potentially mutualistic root endophytic fungi. Our results advance the mechanistic study of intraspecific variation in plant–soil–RAB interactions.


Mycorrhiza ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 773-780
Author(s):  
Saskia Klink ◽  
Philipp Giesemann ◽  
Timo Hubmann ◽  
Johanna Pausch

Abstract Data for stable C and N isotope natural abundances of arbuscular mycorrhizal (AM) fungi are currently sparse, as fungal material is difficult to access for analysis. So far, isotope analyses have been limited to lipid compounds associated with fungal membranes or storage structures (biomarkers), fungal spores and soil hyphae. However, it remains unclear whether any of these components are an ideal substitute for intraradical AM hyphae as the functional nutrient trading organ. Thus, we isolated intraradical hyphae of the AM fungus Rhizophagus irregularis from roots of the grass Festuca ovina and the legume Medicago sativa via an enzymatic and a mechanical approach. In addition, extraradical hyphae were isolated from a sand-soil mix associated with each plant. All three approaches revealed comparable isotope signatures of R. irregularis hyphae. The hyphae were 13C- and 15N-enriched relative to leaves and roots irrespective of the plant partner, while they were enriched only in 15N compared with soil. The 13C enrichment of AM hyphae implies a plant carbohydrate source, whereby the enrichment was likely reduced by an additional plant lipid source. The 15N enrichment indicates the potential of AM fungi to gain nitrogen from an organic source. Our isotope signatures of the investigated AM fungus support recent findings for mycoheterotrophic plants which are suggested to mirror the associated AM fungi isotope composition. Stable isotope natural abundances of intraradical AM hyphae as the functional trading organ for bi-directional carbon-for-mineral nutrient exchanges complement data on spores and membrane biomarkers.


2003 ◽  
Vol 16 (1) ◽  
pp. 131 ◽  
Author(s):  
J. Bell ◽  
S. Wells ◽  
D. A. Jasper ◽  
L. K. Abbott

Field experiments were conducted at rehabilitation sites at two contrasting mines in Western Australia. At both mines, Acacia spp. are important components of the rehabilitation ecosystem. At a mineral sands mine near Eneabba, dry-root inoculum of the arbuscular mycorrhizal (AM) fungus Glomus invermaium (WUM 10) was introduced into riplines with three rates of phosphate fertiliser application. Plants were assessed for mycorrhizal colonisation and phosphorus status. There was no plant growth benefit from inoculation. A considerable number of infective propagules of indigenous AM fungi was already present in the topsoil. The inoculant fungus as well as the indigenous AM fungi formed mycorrhizas, but only in a small number of Acacia and other native plant species. In a study of AM fungal inoculation at a gold mine rehabilitation site at Boddington, dry-root inoculum of G.�invermaium was applied to riplines prior to seeding. Despite apparently ideal environmental conditions, colonisation of native seedlings was limited. Possible reasons for this were investigated in further experiments that addressed environmental factors such as soil temperature and moisture and factors such as the age of the plant and presence of a colonised cover crop. Inoculum remained infective even under moist conditions in field soil for at least 4 months. Its infectivity decreased in parallel with falling temperatures. However, the level of infectivity present did not ensure extensive colonisation of native plants such as Acacia seedlings in the field. Susceptibility of Acacia seedlings to colonisation by AM fungi appeared to be seasonal, as colonisation increased with increasing daytime temperatures and daylight hours.


1985 ◽  
Vol 15 (6) ◽  
pp. 1061-1064 ◽  
Author(s):  
Paul P. Kormanik

Sweetgum seedlings with vesicular–arbuscular mycorrhizae formed by Glomusetunicatum or Glomusdeserticola in nursery soil with 30 ppm available phosphorus (P) and nonmycorrhizal seedlings grown in nursery soil with 800 ppm available P were outplanted and whole trees were excavated periodically over the next 5 years in the plantation to follow mycorrhizal development. Four months after outplanting, roots of all initially nonmycorrhizal seedlings had formed vesicular–arbuscular mycorrhizae and the degree of root colonization was comparable to that of initially vesicular–arbuscular mycorrhizal seedlings. New feeder roots did not develop on seedlings of any treatment until almost 5 months after planting. By the end of the first growing season and for the remainder of the study, vesicular–arbuscular mycorrhizae development was approximately the same on all seedlings. The proportion of feeder roots colonized by vesicular–arbuscular mycorrhizal fungi stabilized at 65 to 70%; approximately 56% of the cortical tissues of all feeder roots were colonized with arbuscles, vesicles, and hyphae. Periodic assays of the soil in the plantation showed that vesicular–arbuscular mycorrhizal fungal spores gradually declined from an initial high of 3600 spores to 620 spores per 100-cm3 soil sample after 5 years. This decline was probably caused by crown closure of the sweetgum trees which gradually suppressed understory vegetation.


1995 ◽  
Vol 73 (S1) ◽  
pp. 1284-1290 ◽  
Author(s):  
Peter Jeffries

The term mycoparasitism applies strictly to those relationships in which one living fungus acts as a nutrient source for another, but fungicolous relationships may also be included in which nutrient exchange has not been shown. Fungicolous fungi have a constant but indeterminate association with another fungus, and it can be difficult to demonstrate a true parasitic relationship. Mycoparasitic relationships can be necrotrophic or biotrophic, and can be classified on the basis of the host–parasite interface as contact necrotrophs, invasive necrotrophs, haustorial biotrophs, intracellular biotrophs, or fusion biotrophs depending on the intimacy of the relationship. In natural ecosystems, it is proposed that mycoparasitic relationships play an important role in the development of fungal communities. Two specific examples have been chosen to illustrate the general principles of mycoparasitism: the necrotrophic invasion of spores of arbuscular mycorrhizal fungi and the biotrophic invasion of mucoralean hosts by haustorial mycoparasites. Key words: mycoparasitism, fungicolous fungi, arbuscular mycorrhizal fungi, fungal ecology.


2020 ◽  
Author(s):  
V. Bala Chaudhary ◽  
Sarah Nolimal ◽  
Moisés A. Sosa-Hernández ◽  
Cameron Egan ◽  
Jude Kastens

SUMMARYDispersal is a key process driving local-scale community assembly and global-scale biogeography of plant symbiotic arbuscular mycorrhizal (AM) fungal communities. A trait-based approach could improve predictions regarding how AM fungal aerial dispersal varies by species.We conducted month-long collections of aerial AM fungi for 12 consecutive months in an urban mesic environment at heights of 20 m. We measured functional traits of all collected spores and assessed aerial AM fungal community structure both morphologically and with high-throughput sequencing.Large numbers of AM fungal spores were present in the air over the course of one year and these spores were more likely to exhibit traits that facilitate dispersal. Aerial spores were smaller than average for Glomeromycotinan fungi. Trait-based predictions indicate that nearly 1/3 of described species from diverse genera demonstrate the potential for aerial dispersal. Diversity of aerial AM fungi was relatively high (20 spore species and 17 virtual taxa) and both spore abundance and community structure shifted temporally.The prevalence of aerial dispersal in arbuscular mycorrhizas is perhaps greater than previously indicated and a hypothesized model of AM fungal dispersal mechanisms is presented. Anthropogenic soil impacts may initiate the dispersal of disturbance-tolerating AM fungal species and facilitate community homogenization.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 463A-463
Author(s):  
Rhoda Burrows ◽  
Francis Pfleger

Growing a plant host in association with other plant species (i.e., increasing diversity) changes the composition of the associated arbuscular–mycorrhizal (AM) fungal community. We tested whether this alteration in the fungal community causes significant differences in the growth of Schizachyrium scoparium L. (Little Bluestem, a C4 grass) or Lespedeza capitata L. (Bush clover, a legume). Seedlings were transplanted into pasteurized soil inoculated with soil from monoculture plots of Schizachyrium or Lespedeza, respectively, vs. plots containing one, seven, or 15 additional plant species. Soil washes from a composite of the plots were added to all pots, including non-inoculated controls, to reduce differences in the non-AM microbial communities. Spore counts of the inoculum from Lespedeza plots showed increasing numbers of AM fungal spores and species richness with increasing plant diversity; this was not true with the Schizachyrium plots, possibly because Schizachyrium may be a better host to more species of AM fungi than Lespedeza. Both Schizachyrium and Lespedeza responded to inoculation with increased growth compared to non-inoculated controls. Tissue analyses of both species showed that inoculation increased the percentage of Cu, and lowered the percentage of Mn compared to control plants. Schizachyrium showed no significant differences in growth due to inoculum source (1-, 2-, 8-, or 16-species plots); while Lespedeza showed increases in root and shoot weights with increasing source-plot diversity.


Author(s):  
Fuad Ameen ◽  
Steven L. Stephenson ◽  
Saleh Al Nadhari ◽  
Mohamed A. Yassin

e microbial communities associated with desert soils are poorly studied. Moleculartechniques have revealed that these communities are more diverse than previously thought. In thisreview, we have assembled and synthesized available literature on microbiological research directedtowards Arabian Desert soils, with primary emphasis on fungi. Recent molecular techniqueshave generated metagenomics data indicating a relatively high diversity of fungi in deserts, includingthe Arabian Desert. However, most publications dealing with Arabian Desert soils have reportedonly fungi that can be cultured, identified either molecularly or morphologically. As such,the fungal communities and their diversity are still largely unknown. Most functional studies in theArabian Desert deal with the role of arbuscular mycorrhizal fungi in improving plants’ survival inthe harsh conditions of desert. In addition, desert fungi might be utilized in developing sustainableagriculture and biomedical applications. Because of future challenges related to desertification andclimate change, there is a need for additional studies on heat and drought resistant fungi and thefunctions of these organisms in deserts.


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