Arbuscular mycorrhiza and salt tolerance of plants

Although salt has detrimental effects on spore germination of arbuscular mycorrhizal fungi (AMF), their hyphal growth and the colonization rate of plants under laboratory conditions, many salt tolerant plants (the halophytes) are strongly colonized by AMF in their natural habitats. AMF spores in several saline soils consist of to up to 80 % of one single species, Glomus geosporum. In contrast, roots of halophytes are mostly colonized by fungi of the Glomus intraradices group, of which many are as yet uncultured. Salt stress is intimately related to drought in saline habitats. Molecular analyses of genes expressed upon salt stress indicate that aquaporins which facilitate the transfer of water across membranes play a major role in alleviating salt stress in plants. In AMF, genes serving to scavenge reactive oxygen species (ROS) are expressed upon exposure to salt, indicating that fungi have to develop an enhanced oxidative defence. The development of AMF inocula that confer sustained salt tolerance to plants would have enormous practical applications. Many positive reports on salt stress alleviation by AMF exist. However, the state of the art has not yet reached field applications. In contrast to other recent reviews, the present article focuses on ecological aspects of the symbiosis between AMF and halophytes. It also emphasizes the complexity of the interactions between salt and drought stress as well as the role of AMF in alleviating salt stress.     

Effect of phenanthrene and Rhodotorula glutinis on arbuscular mycorrhizal fungus colonization of maize roots

The effect of the polycyclic aromatic hydrocarbon (PAH) phenanthrene and the yeast Rhodotorula glutinis on the arbuscular mycorrhizal fungus (AMF) Glomus geosporum colonizing maize roots, was studied. During a 90-day experiment, the highest G. geosporum colonization values were found in control plants. Mycorrhiza root length, measured both on the basis of percentage of root colonization and on the activity of succinate dehydrogenase, showed similar patterns in different phenanthrene treatments. The presence of phenanthrene in the substrate reduced G. geosporum intraradical colonization. The presence of R. glutinis did not enhance AMF colonization in the presence of phenanthrene. The biomass of the external mycelium estimated on the basis of the fatty acid 16:1 omega 5 concentration showed a progressive increase through time, and the amounts of this fatty acid differed among treated and untreated substrates. However, this increase was found to be lowest in the phenanthrene and Rhodotorula treatment at 60 days. There was less phenanthrene accumulation in roots of maize inoculated with AMF and the yeast than in roots inoculated only with AMF. A similar pattern was observed in the phenanthrene content of G. geosporum spores collected after 90 days.     

西双版纳四种壳斗科植物丛枝菌根状况的初步研究

研究了西双版纳热带次生林中杯丝锥(Castanopsis calathiformis)、红锥(C.hys-trix)、印度锥(C.indica)和截果柯(Lithocarpus truncatus)4种壳斗科植物的丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)的侵染状况,并从这些植物的根际土壤中分离鉴定了隶属于球囊霉属(Glomus)、巨孢囊霉属(Gigaspora)、盾巨孢囊霉属(Scutellospora)和无梗囊霉属(Acaulospora)的10种丛枝菌根真菌。这4种壳斗科植物根际AMF的孢子密度为14~22个.100g-1土壤,种的丰富度在4~7,平均频度为60.00%,相对多度为4.41%~22.06%,丛枝菌根真菌的定居水平达46.26%~51.40%。     

Evidence of differences between the communities of arbuscular mycorrhizal fungi colonizing galls and roots of Prunus persica infected by the root-knot nematode Meloidogyne incognita

Arbuscular mycorrhizal fungi (AMF) play important roles as plant protection agents, reducing or suppressing nematode colonization. However, it has never been investigated whether the galls produced in roots by nematode infection are colonized by AMF. This study tested whether galls produced by Meloidogyne incognita infection in Prunus persica roots are colonized by AMF. We also determined the changes in AMF composition and biodiversity mediated by infection with this root-knot nematode. DNA from galls and roots of plants infected by M. incognita and from roots of noninfected plants was extracted, amplified, cloned, and sequenced using AMF-specific primers. Phylogenetic analysis using the small-subunit (SSU) ribosomal DNA (rDNA) data set revealed 22 different AMF sequence types (17 Glomus sequence types, 3 Paraglomus sequence types, 1 Scutellospora sequence type, and 1 Acaulospora sequence type). The highest AMF diversity was found in uninfected roots, followed by infected roots and galls. This study indicates that the galls produced in P. persica roots due to infection with M. incognita were colonized extensively by a community of AMF, belonging to the families Paraglomeraceae and Glomeraceae, that was different from the community detected in roots. Although the function of the AMF in the galls is still unknown, we hypothesize that they act as protection agents against opportunistic pathogens.     

Effect of Host Plants and Inoculum Forms on the Inoculum Potential of Arbuscular Mycor rhizal Fungi

The effects of inoculum forms (single-spore, multi-spores, or colonized root pieces) and host plants (Nicotiana tabacum L., Sorghum sudanense(Piper) Stapf, and Trifolium repens L. ) on the development and inoculum potential (IP) of the arbuscular mycorrhizal fungi (AMF): Glomus macrocarpum Tul & Tul, Glomus mosseae (Nicol & Gerd. ) Gerdemann & Trappe, Glomus versiforme (Karsten) Berch, and Sclerocystis sinuosa Gerdemann & Bakhi cultured in pots were investigated. The lag phase of treatment with 50 spores or 0.5 g (fresh weight) of colonized root pieces was 4 weeks, much shorter than that of the treatment with 1 spore (8 weeks); the value of IP(VIP) and percentage of root colonization(PRC) of the former were greater than those of the latter. Only on the early stages of colonization was there difference between the 50 spores and the 0.5 g (fresh weight) of colonized root piece inoculation treatments. The IP per plant inoculated with 0. 5 g (fresh weight) of colonized mot pieces of AMF was greater than that of the other two treatments except G. vers/forme on Nicotiana tabacum, while the PRC of the plants inoculated with 50 spores and 0. 5 g (fresh weight) of colonized root pieces of AMF was higher than that of the 1 spore inoculation after 10 weeks. The VIP of AMF on Trifolium repens was significantly higher than that on the other two hosts. The VIP of G. mosseae, G. versiforme, and S. sinuosa was respectively greater than that of G. macrocarpum. This suggested that different species of AMF produced different VIP of the inoculum. Nicotiaha tabacum was much better than the other host plants which used to be inoculated with single spore, and to produce inocula of AMF.     

Bacteria associated with spores of the arbuscular mycorrhizal fungi Glomus geosporum and Glomus constrictum

Spores of the arbuscular mycorrhizal fungi (AMF) Glomus geosporum and Glomus constrictum were harvested from single-spore-derived pot cultures with either Plantago lanceolata or Hieracium pilosella as host plants. PCR-denaturing gradient gel electrophoresis analysis revealed that the bacterial communities associated with the spores depended more on AMF than host plant identity. The composition of the bacterial populations linked to the spores could be predominantly influenced by a specific spore wall composition or AMF exudate rather than by specific root exudates. The majority of the bacterial sequences that were common to both G. geosporum and G. constrictum spores were affiliated with taxonomic groups known to degrade biopolymers (Cellvibrio, Chondromyces, Flexibacter, Lysobacter, and Pseudomonas). Scanning electron microscopy of G. geosporum spores revealed that these bacteria are possibly feeding on the outer hyaline spore layer. The process of maturation and eventual germination of AMF spores might then benefit from the activity of the surface microorganisms degrading the outer hyaline wall layer.     

Genetic structure of arbuscular mycorrhizal populations in fallow and cultivated soils

The impact of fallowing on the genetic structure of arbuscular mycorrhizal fungi (AMF) was studied by hierarchical sampling of spores from four plots in a fallow and a cultivated field. A nested multiplex PCR approach was used to assign the spores to genotypes. Variable introns of the two protein-coding genes GmFOX2 and GmTOR2 were used as co-dominant genetic markers together with the large subunit (LSU) rDNA. The gene diversity and genetic structure of Glomus mosseae, Glomus geosporum and Glomus caledonium were compared within and between the fields. Spores of G. caledonium and G. geosporum were more abundant in the cultivated field, whereas G. mosseae was more frequent in the fallow field. The number of genotypes was not different between the two fields. Analysis of gene diversity of G. caledonium in the fallow field indicated that a larger part of the heterogeneity could be attributed to variation between plots rather than subplots, suggesting that the lack of soil cultivation resulted in more heterogeneous population genetic structures. Analyses of haplotype networks of the fungi suggested a subdivision of G. mosseae haplotypes between the two fields, whereas no such division was seen in G. geosporum and G. caledonium. The results show that agricultural practices differently affect both the abundance and the population structure of different AMF species.     

Biodiversity of arbuscular mycorrhizal fungi in roots and soils of two salt marshes

The occurrence of arbuscular mycorrhizal fungi (AMF) was assessed by both morphological and molecular criteria in two salt marshes: (i) a NaCl site of the island Terschelling, Atlantic Coast, the Netherlands and (ii) a K₂CO₃ marsh at Schreyahn, Northern Germany. The overall biodiversity of AMF, based on sequence analysis, was comparably low in roots at both sites. However, the morphological spore analyses from soil samples of both sites exhibited a higher AMF biodiversity. Glomus geosporum was the only fungus of the Glomerales that was detected both as spores in soil samples and in roots of the AMF-colonized salt plants Aster tripolium and Puccinellia sp. at both saline sites and on all sampling dates (one exception). In roots, sequences of Glomus intraradices prevailed, but this fungus could not be identified unambiguously from DNA of soil spores. Likewise, Glomus sp. uncultured, only deposited as sequence in the database, was widely detected by DNA sequencing in root samples. All attempts to obtain the corresponding sequences from spores isolated from soil samples failed consistently. A small sized Archaeospora sp. was detected, either/or by morphological and molecular analyses, in roots or soil spores, in dead AMF spores or orobatid mites. The study noted inconsistencies between morphological characterization and identification by DNA sequencing of the 5.8S rDNA-ITS2 region or part of the 18S rDNA gene. The distribution of AMF unlikely followed the salt gradient at both sites, in contrast to the zone formation of plant species. Zygotes of the alga Vaucheria erythrospora (Xanthophyceae) were retrieved and should not be misidentified with AMF spores.     

Growth of mycorrhizal tomato and mineral acquisition under salt stress

 High salt levels in soil and water can limit agricultural production and land development in arid and semiarid regions. Arbuscular mycorrhizal fungi (AMF) have been shown to decrease plant yield losses in saline soils. The objective of this study was to examine the growth and mineral acquisition responses of greenhouse-grown tomato to colonization by the AMF Glomus mosseae [(Nicol. And Gerd.) Gerd. and Trappe] under varied levels of salt. NaCl was added to soil in the irrigation water to give an EC_e of 1.4 (control), 4.7 (medium) and 7.4 dS m^–1 (high salt stress). Plants were grown in a sterilized, low P (silty clay) soil-sand mix. Mycorrhizal colonization was higher in the control than in saline soil conditions. Shoot and root dry matter yields and leaf area were higher in mycorrhizal than in nonmycorrhizal plants. Total accumulation of P, Zn, Cu, and Fe was higher in mycorrhizal than in nonmycorrhizal plants under both control and medium salt stress conditions. Shoot Na concentrations were lower in mycorrhizal than in nonmycorrhizal plants grown under saline soil conditions. The improved growth and nutrient acquisition in tomato demonstrate the potential of AMF colonization for protecting plants against salt stress in arid and semiarid areas. Accepted: 21 February 2000     

云南金顶铅锌矿区丛枝菌根真菌多样性的研究

对云南金顶铅锌矿区丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)资源进行了调查,从32种植物的83个根际土壤样本中分离鉴定出5属36种丛枝菌根真菌,其中无梗囊霉属Acaulospora 5种、内养囊霉属Entrophospora 2种、巨孢囊霉属Gigaspora 1种、球囊霉属Glomus 24种及盾巨孢囊霉属Scutellospora 4种。球囊霉属和无梗囊霉属为金顶铅锌矿区中丛枝菌根真菌的优势属,沃克球囊霉Glomus walkeri是我国的新记录种。近明球囊霉Glomus claroideum、明球囊霉G.clarum、缩球囊霉G.constrictium、地球囊霉G.geosporum、摩西球囊霉G.mossaea、膨胀球囊霉G.pansihalos和疣突球囊霉G.verruculosum是金顶铅锌矿区的优势种;金顶铅锌矿区土壤中丛枝菌根真菌的孢子密度为495-11175个/100g土,平均3368±291(SE,标准误差)个/100g土,每种植物根际土壤中丛枝菌根真菌的物种丰富度为2-20种,平均11.5种;金顶铅锌矿区植物根际土壤中较高的AMF孢子密度和物种丰富度说明AMF对重金属污染具有较强的抗(耐受)性。     

Diversity of Arbuscular Mycorrhizal Fungi Associated with Plants Growing in Fly Ash Pond and Their Potential Role in Ecological Restoration

Root colonization and diversity of arbuscular mycorrhizal fungi (AMF) were analyzed in plants growing in fly ash pond. Eight species could be separated morphologically, while phylogenetic analyses after PCR amplification of the ITS region followed by RFLP and sequencing revealed seven different AM fungal sequence types. Phylogenetic analysis showed that these sequences cluster into four discrete groups, belonging to the genus Glomus and Archaeospora. Inoculation of plants with spores of AM fungal consortia (Glomus etunicatum, Glomus heterogama, Glomus maculosum, Glomus magnicaule, Glomus multicaule, Glomus rosea, Scutellospora heterogama, and Scutellospora nigra) along with colonized root pieces increased the growth (84.9%), chlorophyll (54%), and total P content (44.3%) of Eucalyptus tereticornis seedlings grown on fly ash compared to non-inoculated seedlings. The growth improvement was the consequence of increased P nutrition and decreased Al, Fe, Zn, and Cu accumulations. These observations suggested that the inoculation of tree seedlings with stress adapted AM fungi aid in the reclamation of fly ash ponds.     

Chemical defense,mycorrhizal colonization and growth responses in <Emphasis Type="Italic">Plantago lanceolata</Emphasis> L.

Allelochemicals defend plants against herbivore and pathogen attack aboveground and belowground. Whether such plant defenses incur ecological costs by reducing benefits from plant mutualistic symbionts is largely unknown. We explored a potential trade-off between inherent plant chemical defense and belowground mutualism with arbuscular mycorrhizal fungi (AMF) in Plantago lanceolata L., using plant genotypes from lines selected for low and high constitutive levels of the iridoid glycosides (IG) aucubin and catalpol. As selection was based on IG concentrations in leaves, we first examined whether IG concentrations covaried in roots. Root and leaf IG concentrations were strongly positively correlated among genotypes, indicating genetic interdependence of leaf and root defense. We then found that root AMF arbuscule colonization was negatively correlated with root aucubin concentration. This negative correlation was observed both in plants grown with monocultures of Glomus intraradices and in plants colonized from whole-field soil inoculum. Overall, AMF did not affect total biomass of plants; an enhancement of initial shoot biomass was offset by a lower root biomass and reduced regrowth after defoliation. Although the precise effects of AMF on plant biomass varied among genotypes, plants with high IG levels and low AMF arbuscule colonization in roots did not produce less biomass than plants with low IG and high AMF arbuscule colonization. Therefore, although an apparent trade-off was observed between high root chemical defense and AMF arbuscule colonization, this did not negatively affect the growth responses of the plants to AMF. Interestingly, AMF induced an increase in root aucubin concentration in the high root IG genotype of P. lanceolata. We conclude that AMF does not necessarily stimulate plant growth, that direct plant defense by secondary metabolites does not necessarily reduce potential benefits from AMF, and that AMF can enhance concentrations of root chemical defenses, but that these responses are plant genotype-dependent.     

Violets of the section Melanium, their colonization by arbuscular mycorrhizal fungi and their occurrence on heavy metal heaps

Violets of the sections Melanium were examined for their colonization by arbuscular mycorrhizal fungi (AMF). Heartsease (Viola tricolor) from several heavy metal soils was AMF-positive at many sites but not at extreme biomes. The zinc violets Viola lutea ssp. westfalica (blue zinc violet) and ssp. calaminaria (yellow zinc violet) were always AMF-positive on heavy metal soils as their natural habitats. As shown for the blue form, zinc violets germinate independently of AMF and can be grown in non-polluted garden soils. Thus the zinc violets are obligatorily neither mycotrophs nor metalophytes. The alpine V. lutea, likely ancestor of the zinc violets, was at best poorly colonized by AMF. As determined by atomic absorption spectrometry, the contents of Zn and Pb were lower in AMF colonized plants than in the heavy metal soils from where the samples had been taken. AMF might prevent the uptake of toxic levels of heavy metals into the plant organs. Dithizone staining indicated a differential deposition of heavy metals in tissues of heartsease. Leaf hairs were particularly rich in heavy metals, indicating that part of the excess of heavy metals is sequestered into these cells.     

Arbuscular mycorrhizal fungi differ in affecting the flowering of a host plant under two soil phosphorus conditions

Aims Studies have showed that arbuscular mycorrhizal fungi (AMF) can greatly promote the growth of host plants, but how AMF affect flowering phenology of host plants is not well known. Here, we conducted a pot experiment to test whether life cycle and flowering phenology traits of host plant Medicago truncatula Gaertn can be altered by AMF under low and high soil phosphorus (P) levels.Methods The experiment was conducted in a greenhouse at Zhejiang University in China (120°19′E, 30°26′N) and had a completely randomized design with two factors: AMF treatments and soil P levels. Six AMF species (Acaulospora scrobiculata, As; Gigaspora margarita, Gma; Funneliformis geosporum, Fg; Rhizophagus intraradices, Ri; Funneliformis mosseae, Fmo and Glomus tortuosum, Gt.) were used, and two soil P levels (24.0 and 5.7 mg kg^-1 Olsen-soluble P) were designed. The six AMF species were separately inoculated or in a mixture (Mix), and a non-AMF control (NAMF) was included. When plants began to flower, the number of flowers in each pot was recorded daily. During fruit ripening, the number of mature fruits was also recorded daily. After ~4 months, the biomass, biomass P content and AMF colonization of host plant were measured. Correlation between root colonization and first flowering time, or P content and first flowering time was analyzed.Important findings Under the low P level, first flowering time negatively correlated with root colonization and biomass P. Only host plants with AMF species As, Fg, Ri, or Mix were able to complete their life cycle within 112 days after sowing. And treatment with AMF species Fg, Gt, or As resulted in two periods of rapid flower production while other fungi treatments resulted in only one within 112 days after sowing. The cumulative number of flowers produced and biomass P content were highest with species Fg. Host biomass allocation significantly differed depending on the species of AMF. Under both soil P levels, the host plant tended to allocate more biomass to fruits in the Mix treatment than in the other treatments. These results indicated that the effects of AMF on host flowering phenology and biomass allocation differed depending on AMF species and soil P levels.     

Effect of edaphic factors and seasonal variation on spore density and root colonization of arbuscular mycorrhizal fungi in sugarcane fields

Sugarcane fields in 14 different study sites were analyzed for the presence of different arbuscular mycorrhizal fungal (AMF) spores. A total of 23 AMF species representing four genera were identified, among which Glomus fasciculatum and G. mosseae were the dominant species. The mean spore density in the root-zone soils of sugarcane plants varied from 119 to 583 per 100 g of soil, and the mean percentage root colonization varied from 60 to 89 %. A study of the effect of edaphic factors on AM spore density and percentage root colonization revealed a positive correlation between pH and AMF spore density and root colonization and a negative correlation between electrical conductivity, nitrogen, and phosphorus. A positive correlation was observed between AMF spore density and root colonization. Season was also found to play a vital role in determining AMF spore density and percentage root colonization, with high spore density and root colonization observed during the summer season and lower spore densities and root colonization during the winter season.     

Colonization of pennycresses (Thlaspi spp.) of the Brassicaceae by arbuscular mycorrhizal fungi

Members of the Brassicaceae are generally believed to be non-mycorrhizal. Pennycress (Thlaspi) species of this family from diverse locations in Slovenia, Austria, Italy and Germany were examined for their colonisation by arbuscular mycorrhizal fungi (AMF). Meadow species (T. praecox, T. caerulescens and T. montanum) were sparsely but distinctly colonised, as indicated by the occurrence of intraradical hyphae, vesicles, coils, and occasionally arbuscules. Species from other locations were poorly colonised, but arbuscules were not discernible. The genus Thlaspi comprises several heavy metal hyperaccumulating species (T. caerulescens, T. goesingense, T. calaminare, T. cepaeifolium). All samples collected from heavy metal soils were at best poorly colonized. Thus the chance is small to find a "hypersystem" in phytoremediation consisting of an AM fungus which prevents the uptake of the major part of the heavy metals and of a Thlaspi species which effectively deposits the residual heavy metals inevitably taken up into its vacuoles. In two different PCR approaches, fungal DNA was amplified from most of the Thlaspi roots examined, even from those with a very low incidence of AMF colonization. Sequencing of the 28S- and 18S-rDNA PCR-products revealed that different Thlaspi field samples were colonized by Glomus intraradices and thus by a common AM fungus. However, none of the sequences obtained was identical to any other found in the present study or deposited in the databanks, which might indicate that a species continuum exists in the G. intraradices clade. An effective colonization of Thlaspi by AMF could not be established in greenhouse experiments. Although the data show that Thlaspi can be colonized by AMF, it is doubtful whether an effective symbiosis with the mutual exchange of metabolites is formed by both partners.     

Molecular diversity of arbuscular mycorrhizal fungi in onion roots from organic and conventional farming systems in the Netherlands

Diversity and colonization levels of naturally occurring arbuscular mycorrhizal fungi (AMF) in onion roots were studied to compare organic and conventional farming systems in the Netherlands. In 2004, 20 onion fields were sampled in a balanced survey between farming systems and between two regions, namely, Zeeland and Flevoland. In 2005, nine conventional and ten organic fields were additionally surveyed in Flevoland. AMF phylotypes were identified by rDNA sequencing. All plants were colonized, with 60% for arbuscular colonization and 84% for hyphal colonization as grand means. In Zeeland, onion roots from organic fields had higher fractional colonization levels than those from conventional fields. Onion yields in conventional farming were positively correlated with colonization level. Overall, 14 AMF phylotypes were identified. The number of phylotypes per field ranged from one to six. Two phylotypes associated with the Glomus mosseae–coronatum and the G. caledonium–geosporum species complexes were the most abundant, whereas other phylotypes were infrequently found. Organic and conventional farming systems had similar number of phylotypes per field and Shannon diversity indices. A few organic and conventional fields had larger number of phylotypes, including phylotypes associated with the genera Glomus-B, Archaeospora, and Paraglomus. This suggests that farming systems as such did not influence AMF diversity, but rather specific environmental conditions or agricultural practices. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Authors Guillermo A. Galván and István Parádi contributed equally to this research and share first co-authorship.     

Modularity Reveals the Tendency of Arbuscular Mycorrhizal Fungi To Interact Differently with Generalist and Specialist Plant Species in Gypsum Soils

Patterns in plant–soil biota interactions could be influenced by the spatial distribution of species due to soil conditions or by the functional traits of species. Gypsum environments usually constitute a mosaic of heterogeneous soils where gypsum and nongypsum soils are imbricated at a local scale. A case study of the interactions of plants with arbuscular mycorrhizal fungi (AMF) in gypsum environments can be illustrative of patterns in biotic interactions. We hypothesized that (i) soil characteristics might affect the AMF community and (ii) there are differences between the AMF communities (modules) associated with plants exclusive to gypsum soils (gypsophytes) and those associated with plants that show facultative behavior on gypsum and/or marly-limestone soils (gypsovags). We used indicator species and network analyses to test for differences between the AMF communities harbored in gypsophyte and gypsovag plants. We recorded 46 operational taxonomic units (OTUs) belonging to nine genera of Glomeromycota. The indicator species analysis showed two OTUs preferentially associating with gypsum soils and three OTUs preferentially associating with marly-limestone soils. Modularity analysis revealed that soil type can be a major factor shaping AMF communities, and some AMF groups showed a tendency to interact differently with plants that had distinct ecological strategies (gypsophytes and gypsovags). Characterization of ecological networks can be a valuable tool for ascertaining the potential influence of above- and below-ground biotic interactions (plant-AMF) on plant community composition.     

Niche partitioning in arbuscular mycorrhizal communities in temperate grasslands: a lesson from adjacent serpentine and nonserpentine habitats

Arbuscular mycorrhizal fungi (AMF) represent an important soil microbial group playing a fundamental role in many terrestrial ecosystems. We explored the effects of deterministic (soil characteristics, host plant life stage, neighbouring plant communities) and stochastic processes on AMF colonization, richness and community composition in roots of Knautia arvensis (Dipsacaceae) plants from three serpentine grasslands and adjacent nonserpentine sites. Methodically, the study was based on 454‐sequencing of the ITS region of rDNA. In total, we detected 81 molecular taxonomical operational units (MOTUs) belonging to the Glomeromycota. Serpentine character of the site negatively influenced AMF root colonization, similarly as higher Fe concentration. AMF MOTUs richness linearly increased along a pH gradient from 3.5 to 5.8. Contrary, K and Cr soil concentration had a negative influence on AMF MOTUs richness. We also detected a strong relation between neighbouring plant community composition and AMF MOTUs richness. Although spatial distance between the sampled sites (c. 0.3–3 km) contributed to structuring AMF communities in K. arvensis roots, environmental parameters were key factors in this respect. In particular, the composition of AMF communities was shaped by the complex of serpentine conditions, pH and available soil Ni concentration. The composition of AMF communities was also dependent on host plant life stage (vegetative vs. generative). Our study supports the dominance of deterministic factors in structuring AMF communities in heterogeneous environment composed of an edaphic mosaic of serpentine and nonserpentine soils.