Root colonisation by arbuscular mycorrhizal, fine endophytic and dark septate fungi across a pH gradient in acid beech forests

Earthworms and arbuscular mycorrhizal fungi (AMF) modify soil physical and chemical properties. However, little is known about how their interactions affect water-stable aggregation, glomalin and crop performance. A greenhouse experiment was run for 9 months to test the effects of earthworms (endogeic, Pontoscolex corethrurus; and epigeic, Dichogaster bolaui) and AMF (none, Glomus etunicatum and Scutellospora verrucosa) on water-stable aggregation, glomalin levels in aggregate size classes and crop performance. The test crop was pigeonpea (Cajanus cajan (L.) Millsp.). The soil material used for the experiment was a humic nitisol from central Kenya mixed with sand (ratio 1:1). Grass residue (equivalent to 20tha–1) was placed on top. The AMF root colonisation and external hyphal length, water-stable macroaggregates and microaggregates, total and easily-extractable glomalin in aggregate size classes, plant biomass and plant N and P uptake were measured. Earthworms were a major source of variation for soil aggregation, glomalin content and crop performance. The epigeic earthworms (D. bolaui) increased the amount of water-stable macroaggregates (by 10%) and glomalin in microaggregates and improved crop (growth and biomass) performance. The endogeic earthworms (P. corethrurus) reduced external hyphal length, root colonisation and crop performance but had no effect on water-stable aggregates and glomalin levels in in aggregate size classes. A significant AMF×earthworm interaction was observed for plant biomass and concentrations of nitrogen (N) and phosphorus (P). The AMF species together with epigeic earthworms increased plant biomass and N and P concentrations. Our results contribute to the understanding of interactions between AMF and earthworms in relation to soil aggregation, plant productivity and nutrient uptake.

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Colonization by arbuscular mycorrhizal and fine endophytic fungi in herbaceous vegetation in the Canadian High Arctic

Canadian Journal of Botany ◽

10.1139/b04-111 ◽

2004 ◽

Vol 82 (11) ◽

pp. 1547-1556 ◽

Cited By ~ 40

Author(s):

Pål Axel Olsson ◽

Bente Eriksen ◽

Anders Dahlberg

Keyword(s):

Endophytic Fungi ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Ellesmere Island ◽

Inoculum Potential ◽

Devon Island ◽

Dark Septate Fungi ◽

Banks Island ◽

Glomus Tenue ◽

Ellef Ringnes Island

The occurrence of arbuscular mycorrhizal (AM) fungi was surveyed along a latitudinal gradient in Arctic Canada including Banks Island (73°N), Devon Island (74°N), Ellesmere Island (76°N), and the Magnetic North Pole at Ellef Ringnes Island (78°N). At Banks Island, AM fungi were present and colonized at a high intensity in all specimens of Potentilla hookeriana Lehm. – Potentilla pulchella R.Br., Arnica angustifolia Vahl, and Erigeron uniflorus L. ssp. eriocephalus (Vahl ex Hornen.) Cronq. sampled. The soil collected under these plants showed a high inoculum potential when tested at greenhouse conditions using Plantago lanceolata L. as a bait plant. Occasional occurrence of AM fungi was recorded in Festuca hyperborea Holmen ex Frederiksen, Trisetum spicatum (L.) Richt., and Potentilla hookeriana – Potentilla pulchella at Devon Island. Despite the fact that potential AM plants are present, no AM was found at the two most northern sites, Ellesmere Island and Ellef Ringnes Island. There seems to be climatic or dispersal limitations to AM colonization at these northern sites. Fine endophytic fungi, formerly named Glomus tenue (Grenall) I.R. Hall, were recorded at all four sites, but most frequently at Banks Island. We thereby provide further evidence that fine endophytes are more frequent in harsh climatic conditions than AM fungi. There was a relatively high proportion of nonmycorrhizal plant species at all sites, and this proportion increased towards the north.Key words: arctic, arbuscular mycorrhiza, fine endophytes, dark septate fungi.

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Environmental factors driving arbuscular mycorrhizal fungal communities associated with endemic woody plant Picconiaazorica on native forest of Azores

Annals of Microbiology ◽

10.1007/s13213-019-01535-x ◽

2019 ◽

Vol 69 (13) ◽

pp. 1309-1327 ◽

Cited By ~ 4

Author(s):

Catarina Drumonde Melo ◽

Christopher Walker ◽

Claudia Krüger ◽

Paulo A.V. Borges ◽

Sara Luna ◽

...

Keyword(s):

Environmental Factors ◽

Mycorrhizal Fungi ◽

Natural Disturbance ◽

Arbuscular Mycorrhizal ◽

Soil Condition ◽

Spore Density ◽

Native Forest ◽

Environmental Filters ◽

Root Colonisation ◽

Amf Communities

Abstract Purpose Arbuscular mycorrhizal fungi (AMF) play important key roles in the soil ecosystems as they link plants to the root-inaccessible part of soil. The aims of this study were to investigate which environmental factors influence the spatial and temporal structuring of AMF communities associated to Picconia azorica in two Azorean islands (Terceira and São Miguel islands), and investigate the seasonal variation in AMF communities between the two islands. Methods Communities of AMF associated with P. azorica in native forest of two Azorean islands (Terceira and São Miguel) were characterised by spore morphology or molecular analysis. Results Forty-five AMF spore morphotypes were detected from the four fragments of P. azorica forest representing nine families of AMF. Acaulosporaceae (14) and Glomeraceae (9) were the most abundant families. AMF density and root colonisation varied significantly between islands and sampling sites. Root colonisation and spore density exhibited temporal patterns, which peaked in spring and were higher in Terceira than in São Miguel. The relative contribution of environmental factors showed that factors such as elevation, relative air humidity, soil pH, and soil available P, K, and Mg influenced AMF spore production and root colonisation. Conclusion Different sporulation patterns exhibited by the members of the commonest families suggested different life strategies. Adaptation to a particular climatic and soil condition and host phenology may explain seasonal differences in sporulation patterns. Cohorts of AMF associated to P. azorica are shaped by regional processes including environmental filters such as soil properties and natural disturbance.

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Endophytic fungal symbionts associated with gypsophilous plants

Botany ◽

10.1139/cjb-2013-0178 ◽

2014 ◽

Vol 92 (4) ◽

pp. 295-301 ◽

Cited By ~ 19

Author(s):

Andrea Porras-Alfaro ◽

Srivathsan Raghavan ◽

Margaret Garcia ◽

Robert L. Sinsabaugh ◽

Donald O. Natvig ◽

...

Keyword(s):

Arid Regions ◽

Microscopic Analysis ◽

Arbuscular Mycorrhizal ◽

Wide Distribution ◽

Flowering Plant ◽

Fungal Colonization ◽

Specific Substrate ◽

Limited Information ◽

Culture Techniques ◽

Dark Septate Fungi

Gypsum soils (calcium sulfate) occur throughout arid regions of the world. These soils contain a large number of endemic plants. Limited information is available about the microbial symbionts of these plants. We collected eight endemic gypsophilous flowering plant species in New Mexico and characterized their root- and leaf-associated fungi using molecular, microscopic, and culture techniques. Dominant culturable fungi were identified by analysis of the internal transcribed spacer (ITS) rDNA region. Microscopic analysis of roots indicated that gypsophilous plants are colonized primarily by arbuscular mycorrhizal and dark septate fungi. Sporobolus nealleyi Vasey (a gypsophilous grass) showed the greatest percentages of fungal colonization. All fungal isolates belonged to the Ascomycota, dominated by the orders Pleosporales and Sordariales. Isolates in the Alternaria complex were the dominant fungi recovered from leaves, and Monosporascus was the dominant genus recovered from roots. The dominant genera show low plant specificity and wide distribution as plant symbionts in arid regions. The generalist nature of gypsophilous plants with respect to their fungal symbionts could be advantageous for their successful establishment and survival. A common cohort of fungal symbionts could facilitate efficient transfer of nutrients and water in these plants that are restricted to a specific substrate in an environment dominated by extreme conditions.

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Contrasting preferences of arbuscular mycorrhizal and dark septate fungi colonizing boreal and subarctic Avenella flexuosa

Mycorrhiza ◽

10.1007/s00572-013-0526-7 ◽

2013 ◽

Vol 24 (3) ◽

pp. 171-177 ◽

Cited By ~ 13

Author(s):

M. Kauppinen ◽

K. Raveala ◽

P. R. Wäli ◽

A. L. Ruotsalainen

Keyword(s):

Arbuscular Mycorrhizal ◽

Dark Septate Fungi ◽

Avenella Flexuosa

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Asymbiotic mass production of the arbuscular mycorrhizal fungus Rhizophagus clarus

Communications Biology ◽

10.1038/s42003-021-02967-5 ◽

2022 ◽

Vol 5 (1) ◽

Author(s):

Sachiko Tanaka ◽

Kayo Hashimoto ◽

Yuuki Kobayashi ◽

Koji Yano ◽

Taro Maeda ◽

...

Keyword(s):

Life Cycle ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Terrestrial Ecosystems ◽

Hormonal Control ◽

Root Colonisation ◽

Rhizophagus Clarus ◽

Am Symbiosis ◽

Fungal Life Cycle

AbstractArbuscular mycorrhizal (AM) symbiosis is a mutually beneficial interaction between fungi and land plants and promotes global phosphate cycling in terrestrial ecosystems. AM fungi are recognised as obligate symbionts that require root colonisation to complete a life cycle involving the production of propagules, asexual spores. Recently, it has been shown that Rhizophagus irregularis can produce infection-competent secondary spores asymbiotically by adding a fatty acid, palmitoleic acid. Furthermore, asymbiotic growth can be supported using myristate as a carbon and energy source for their asymbiotic growth to increase fungal biomass. However, the spore production and the ability of these spores to colonise host roots were still limited compared to the co-culture of the fungus with plant roots. Here we show that a combination of two plant hormones, strigolactone and jasmonate, induces the production of a large number of infection-competent spores in asymbiotic cultures of Rhizophagus clarus HR1 in the presence of myristate and organic nitrogen. Inoculation of asymbiotically-generated spores promoted the growth of host plants, as observed for spores produced by symbiotic culture system. Our findings provide a foundation for the elucidation of hormonal control of the fungal life cycle and the development of inoculum production schemes.

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Micorriza arbuscular, Mucoromycotina y hongos septados oscuros en helechos y licófitas con distribución en México: una revisión global

Revista de Biología Tropical ◽

10.15517/rbt.v65i3.29443 ◽

2017 ◽

Vol 65 (3) ◽

pp. 1062

Author(s):

Luis Alberto Lara-Pérez ◽

Ramón Zulueta-Rodríguez ◽

Antonio Andrade-Torres

Keyword(s):

Mycorrhizal Fungi ◽

Experimental Studies ◽

Arbuscular Mycorrhizal ◽

Conservation Strategies ◽

Growth And Survival ◽

Dark Septate Fungi ◽

Mycorrhizal Interactions ◽

Taxonomic Groups ◽

Fungal Interactions ◽

Ferns And Lycophytes

Ferns and lycophytes are a group of vascular plants of interest to understand the evolution of mycorrhizal interactions; their preservation is of relevance for their multiple ecological relations. The record of different taxonomic groups of fungi associated with ferns and lycophytes is fragmentary, and the criteria for it identification is inconsistent, which hinders the understanding and determination of mycorrhizal status. The aim of this study was to determine the percentage of the species of ferns and lycophytes with distribution in Mexico, and with information of fungal interactions. A checklist of the presence of arbuscular mycorrhizal fungi (AMF), Mucoromycotina and dark septate fungi (DSF) associated with ferns and lycophytes was integrated through an exhaustive global literature search. In this study, mycorrhizal species was considered by the presence of arbuscules to differentiate with hyphal, vesicular and coils colonization. The study gathered a checklist of mycorrhizal occurrences of 27 families, 61 genus and 137 species of ferns and lycophytes, which covers 13.4 % of the species, 91 % of the genus and 77 % of the families distributed in Mexico. The 78.1 % of the species showed colonization, 56.2 % by AMF, 29.9 % by DSF and 0.72 % by Mucoromycotina fungi. From the total of the species, the higher presences of colonization were in terrestrial, epiphytic, saxicolous, and aquatic plants with 76.6 %, 33.3 %, 20 %, and 6.3 %, respectively. The families of ferns and lycophytes with the higher number of species colonized were Pteridaceae, Polypodiaceae, Aspleniaceae and Dryopteridaceae. The present study showed the widespread associations of AMF and DSF in ferns and lycophytes of Mexico. It is urgently needed to include ferns and lycophytes in studies focused on endomycorhizal interactions, since only 28 species (28 %) were studied in Mexican ecosystems. The majority of studies were focused on sporophytic face (80 %). Nonetheless, to understand the role that plays the mycorrhiza in the establishment of ferns and lycophytes, it is necessary to include the gametophytic face in ecological, molecular and physiological experimental studies. This information is important to implement conservation strategies, because a considerable number of ferns and lycophytes species, depend on these mycorrhizal associations for their growth and survival.

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Crop productivity in relation to species of previous crops and management of previous pasture

Australian Journal of Agricultural Research ◽

10.1071/ar02021 ◽

2002 ◽

Vol 53 (11) ◽

pp. 1271 ◽

Cited By ~ 22

Author(s):

R. H. Harris ◽

G. J. Scammell ◽

W. J. Müller ◽

J. F. Angus

Keyword(s):

Mycorrhizal Fungi ◽

Subterranean Clover ◽

Arbuscular Mycorrhizal ◽

Crop Productivity ◽

Root Disease ◽

Wheat Crop ◽

Surprising Result ◽

Wheat Roots ◽

Root Colonisation ◽

Yield Increase

An experiment at Rutherglen in north-eastern Victoria compared 5 grass-removal methods in subterranean clover-based pastures that were grown before cropping sequences of canola–wheat–lupin–wheat or wheat–wheat–lupin–wheat. The cropping sequences were started in 3 successive years to provide replication in time. Grass removal from the pasture was more effective in winter than in spring and led to yield increases by the first and second crops. The largest increase (80%) was by the first canola crop after winter-cleaned pasture. The yield increase by the equivalent wheat crop was 42%. Since annual grasses and canola do not host the same root pathogens, we conclude that the yield responses were not due to root-disease control but probably to increased N supply. Assays of wheat roots confirmed that root disease was negligible throughout the experiment. Wheat growing in the year after canola yielded 11% more than wheat growing after wheat. The most surprising result was a 17% increase in the yield of wheat growing 3 years after canola compared with wheat growing 3 years after wheat, with wheat–lupin sequences in the intervening years for both systems. We suggest that canola and lupin, both of which are non-hosts of arbuscular mycorrhizal fungi, reduced mycorrhizal root colonisation in the fourth-year wheat crop, leading to less drain on assimilates.

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