Ewald Sieverding

Hohenheim University, Stuttgart, Baden-Württemberg, Germany

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Publications (23)30.56 Total impact

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    ABSTRACT: A new Acaulospora species was isolated from the rhizosphere of Panicum maximum, Sporobolus indicus and Byrsonima crassifolia of a calcareous soil in Bayamo (Cuba). It was successfully propagated in single species cultures obtained after inoculation with multiple spores on Bracharia decumbens and Sorghum vulgare, respectively. It was also detected in several natural and agricultural sites in Northeastern Brazil. The spores are brown-yellow to yellowish brown, (50–)70–95(–112) μm in diam., and have a diagnostic pitted ornamentation on the outer surface of the structural wall layer. The pits are rounded, elliptical to elongated (vermiform or rugulate), and uniformly distributed leaving narrow bridges that regularly give the impression of a raised reticulum. Partial sequences of the LSU rRNA gene confirm the new fungus in a well separated, monophyletic clade within the Acaulosporaceae. The new fungus is here presented under the epithet Acaulospora herrerae in honor to Dr. Ricardo Herrera-Peraza, a highly appreciated former mycorrhizologist from La Habana, Cuba.
    Nova Hedwigia 01/2013; 97:401-413. · 0.81 Impact Factor
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    ABSTRACT: Soil properties and the environment have multiple outcomes on fungal communities. Although, the interaction effects between management intensity, pH, available phosphorus, organic carbon, soil texture and different fractions of water stable macro-aggregates on the communities of microscopic filamentous fungi (MFF), iron phosphate solubilizing fungi (PSF-Fe), and iron and calcium phosphate solubilizing fungi (PSF-(Fe+Ca)), have been previously evaluated in field conditions, this has never been performed in terms of their combined effects, neither with phosphate solubilizing fungi. To assess this, we collected 40 composite soil samples from eight Mexican and Colombian coffee plantations, with different management intensities and physico-chemical edaphic parameters, during 2008-2009. We isolated different communities of MFF, PSF-Fe and PSF-(Fe+Ca), by wet sieving and soil particles culture in Potato-Dextrose-Agar from soil samples, and we classified isolates in terms of their phosphate solubilizing ability. Following the principal component analysis results, we decided to analyze fungal communities and abiotic factors interactions for each country separately. Structural Equation Models revealed that organic carbon was positively associated to MFF richness and number of isolates (lambda>0.58), but its relationship with PSF-Fe and PSF-(Fe+Ca) were variable; while the available phosphorus, pH and water stable macro-aggregate fractions did not show a clear pattern. Management intensity was negatively related to PSF-Fe (lambda < or = -0.21) morphotype richness and the number of isolates in Colombian coffee plantations. We found that the relationships of clay and organic carbon content, and available phosphorus and soil pH, with the species richness and number of isolates of MFF, PSF-Fe and PSF-(Fe+Ca) were highly variable; this made impossible to generalize the responses between saprotrophic fungal groups and geographic zones. The management intensity was not related to species richness and number of isolates of MFF in any coffee areas, while for PSF the relationship could not be defined. The different water stable macro-aggregates fractions did not show a defined pattern in relation to the species richness and the number of isolates of saprophytic and phosphate solubilizing fungi (PSF). This study highlights the need to take into account edaphic and geographic context in order to reach a better understanding of the intensity management effects on MFF and PSF function in agroecosystems.
    Revista de biologia tropical 09/2012; 60(3):1075-96. · 0.55 Impact Factor
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    ABSTRACT: In cereals cultivated in Southern Chilean Andosols, arbuscular mycorrhizal (AM) fungi may play a main role for phosphorus (P) uptake. Because P acquisition at early growth stages is crucial for cereals, we investigated the development of indigenous AM during the first 45 days after planting of two wheat, barley and oats varieties in two typical Andosols of the region, under plastic house. Minimum temperatures were between - 5°C and + 5°C at night and maximum between 18°C and 30°C during day. The results showed that root biomass of all species increased in both soils until 30 days and remained constant thereafter until 45 days. The intensity of AM infection (root area and root biomass infected) was low at 15 days, increased slightly from 15 to 30 days and increased sharply and significantly from 30 to 45 days. Plant species and varieties differed in root biomass formation but not in frequency and intensity of infection with AM structures. Thus, those cereals species and varieties with more root production had higher total mycorrhizal root biomass, and those may potentially benefit more from AM. It is also concluded that during early growth stages cereals invest first into root development and then into AM fungal biomass.
    Journal of soil science and plant nutrition. 09/2012; 12(3):511-524.
  • Revista de biologia tropical 09/2012; 60(3):1075-1096. · 0.55 Impact Factor
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    ABSTRACT: A new fungus in the Glomeromycetes was found in the high alpine and nival altitudes of Switzerland in the rhizosphere of several alpine plant species, with a wide soil pH range from 3.9–7.8. It forms bright yellow to dark yellow spores, 81–100 × 75–82 μm in diameter, laterally on the neck of sporiferous saccules, and has three spore walls. The outer wall is crowded with irregular pits that are 0.9–1.5 × (0.9–)1.5–3.5(–5.5) μm wide and 1.2–2.5 μm deep. Molecular analyses on the ITS region and partial LSU rDNA gene place the fungus phylogenetically in a monophyletic clade within the genus Acaulospora next to A. sieverdingii, A. paulinae, A. cavernata and A. punctata. An updated identification key for Acaulospora species is presented. The new fungus may co-occur in low frequency with species like A. alpina and A. paulinae in the alpine pastures between 2000 and 2600 m asl. However, it often is the most frequently and most abundantly found Acaulospora species at highest altitudes of plant life, i.e. at subnival and nival altitudes, where it was found in pioneer screes of shallowest soils and associated with pioneer plant species like Linaria alpina, Poa alpina and Saxifraga stellaris.
    Nova Hedwigia 08/2012; 95:105-122. · 0.81 Impact Factor
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    ABSTRACT: Concomitant morphological and molecular analyses have led to major breakthroughs in the taxonomic organization of the phylum Glomeromycota. Fungi in this phylum are known to form arbuscular mycorrhiza, and so far three classes, five orders, 14 families and 29 genera have been described. Sensulato, spore formation in 10 of the arbuscular mycorrhiza-forming genera is exclusively glomoid, one is gigasporoid, seven are scutellosporoid, four are entrophosporoid, two are acaulosporoid, and one is pacisporoid. Spore bimorphism is found in three genera, and one genus is associated with cyanobacteria. Here we present the current classification developed in several recent publications and provide a summary to facilitate the identification of taxa from genus to class level.
    IMA fungus. 12/2011; 2(2):191-9.
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    ABSTRACT: Concomitant morphological and molecular analyses have led to major breakthroughs in the taxonomic organization of the phylum Glomeromycota. Fungi in this phylum are known to form arbuscular mycorrhiza, and so far three classes, five orders, 14 families and 29 genera have been described. Sensu lato, spore formation in 10 of the arbuscular mycorrhiza-forming genera is exclusively glomoid, one is gigasporoid, seven are scutellosporoid, four are entrophosporoid, two are acaulosporoid, and one is pacisporoid. Spore bimorphism is found in three genera, and one genus is associated with cyanobacteria. Here we present the current classification developed in several recent publications and provide a summary to facilitate the identification of taxa from genus to class level.
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    ABSTRACT: Combined morphological and molecular biological analyses have achieved major advances in the taxonomy of fungal species in phylum Glomeromycota. In this study, we analyzed which species might not yet be attributed to their correct genus, focusing on Acaulospora myriocarpa , A. undulata, A. nicolsonii, and Scutellospora nodosa. Based on spore wall structure and phylogenetic support, we recombined the taxa as Archaeospora myriocarpa, Ar. undulata, Ambispora nicolsonii, and Cetraspora nodosa.
    Mycotaxon -Ithaca Ny- 11/2011; 117:429-434. · 0.82 Impact Factor
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    ABSTRACT: New ribosomal gene analyses reveal that Entrophospora is non-monophyletic and its type species E. infrequens closely related to Claroideoglomus species, which supports transfer of the Entrophosporaceae from Diversisporales to Glomerales as well as the 'ancestral' Claroideoglomus spp. to Albahypha gen. nov. Entrophospora baltica, supported as a separate clade within Diversisporales, is designated as type species for the new monospecific Sacculosporaceae. Entrophospora nevadensis, phylogenetically close to Diversipora spp. and Otospora bareae, is transferred to Tricispora gen. nov. (Diversiporaceae). Entrophospora, Sacculospora, and Tricispora are morphologically distinguished by spore wall structure, pattern of the two spore pore closures proximal and distal to the sporiferous saccule, and relative spore and sporiferous saccule sizes. The shape of the white hyphae subtending the spore base separates Albahypha spp. from Claroideoglomus spp.
    Mycotaxon -Ithaca Ny- 11/2011; 117:297-316. · 0.82 Impact Factor
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    ABSTRACT: The development of communities of arbuscular mycorrhizal fungi (AMF) was investigated in the subalpine foreland of the glacier Morteratsch located at approx. 1900–2100m a.s.l. near Pontresina (Engiadin’ Ota, Switzerland). In particular, we asked if the succession of AMF communities follows or precedes the primary plant succession, and we checked the mycorrhizal status of the pioneer plant Epilobium fleischeri. Soil samples were taken at pioneer and dense grassland sites established during the last hundred years representing different periods of glacier retreat: 1875–1900, 1940–1950, 1970–1980 and 1990–2000. Extraradical hyphal length densities and AMF spore populations were analyzed in soil samples. Spore formation and mycorrhizal root colonization were monitored in trap cultures grown on Trifolium pratense, Lolium perenne, Plantago lanceolata and Hieracium pilosella or on E. fleischeri over 14 months. We found that E. fleischeri is strongly arbuscular mycorrhizal, but plants in closest distance to the glacier (glacier retreat in the last 4–6 years before sampling) were non-mycorrhizal. Spore densities and root colonization in trap cultures were generally low in samples from glacier stage 1990–2000. Highest spore density and colonization were found for the sites ice-free since 1970–1980, whilst highest AMF species richness and hyphal length densities were found at the sites ice-free since 1875–1900. Our findings show an establishment of a few AMF pioneer species (e.g. Diversispora versiformis and Acaulospora punctata) within 5–10 years and species rich AMF communities at sites ice-free for 100 years (28 species). Their succession generally follows the succession of the plant communities. We conclude that AMF pioneer species might be mainly distributed by wind transport while other AMF fungi (e.g. Glomus rubiforme and Glomus aureum) rather need a below-ground hyphal network to invade new areas.
    Pedobiologia 10/2011; 54(5):321-331. · 1.69 Impact Factor
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    ABSTRACT: Based on concomitant molecular analyses of the ribosomal gene and morphological characteristics, we divide the phylum Glomeromycota into three classes: Glomeromycetes, Archaeosporomycetes, and Paraglomeromycetes. Glomeromycetes are newly organized in three orders: Glomerales and Diversisporales, both forming typical vesicular arbuscular mycorrhiza with higher plants, and Gigasporales, forming arbuscular mycorrhiza without vesicles in the roots but with extra-radical auxiliary cells. Within the phylum, Archaeosporomycetes comprise exclusively bimorphic families and genera. The monogeneric Paraglomeromycetes species form glomoid spores that typically germinate directly through the spore wall instead through their subtending hyphae.
    Mycotaxon -Ithaca Ny- 03/2011; 116:365-379. · 0.82 Impact Factor
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    ABSTRACT: Species in the orders Glomerales and Diversisporales (Glomeromycetes) with glomoid spore formation are reorganized based on combined ribosomal sequence and morphological analyses. Within the Glomerales two genera in the Glomeraceae (Septoglomus, Simiglomus) and one genus in the Claroideoglomeraceae (Viscospora) are proposed as new. Paraglomerales species (thus far monogeneric) also form glomoid spores that may all germinate directly through the spore wall instead through subtending hyphae as in Glomerales.
    Mycotaxon -Ithaca Ny- 03/2011; 116:75-120. · 0.82 Impact Factor
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    ABSTRACT: A new species of the genus Acaulospora (Glomeromycetes) was found in several mountainous to high mountainous grasslands in Switzerland and Southern Chile, at 1850–2050 m and 550–1600 m asl, respectively. The species has yellow-white to creamy and regularly globose to subglobose spores with a diameter of 105–129 μm. It is characterized by an ornamentation on the outer surface of the outer spore wall with point-like, concave and highly regular pits that are 1.1–2.0(–2.7) μm in diameter and at least as deep (1.4–3.5 μm) as wide. Phylogenetic analyses compiling partial sequences of the ITS of the ribosomal DNA place the species adjacent to A. cavernata, A. denticulata, A. paulinae and A. sieverdingii. The new fungus is described here under the epithet A. punctata. Many spores of the fungus were detected in the foreland of the retreating Morteratsch glacier near St. Moritz (Engadin, Switzerland) particularly in pioneer stands dominated by Epilobium fleischeri but also in plant-species rich older grasslands in larger distance to the glacier. It was also found in mountainous managed forests and grasslands in Southern Chile suggesting the worldwide distribution of the fungus in mountainous regions.
    Nova Hedwigia 01/2011; 93:353-362. · 0.81 Impact Factor
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    ABSTRACT: The objective of this study was to test whether soil types can be characterized by their arbuscular mycorrhizal fungal (AMF) communities. To answer this question, a well-defined study area in the temperate climatic zone of Central Europe was chosen with a large spectrum of soils and parent materials. Representative soil samples were taken from three soil types (Cambisol, Fluvisol and Leptosol) at in total 16 sites differing in agricultural land use intensity (9 grasslands and 7 arable lands). AMF spores were isolated and morphologically identified directly from field soils and after reproduction in trap cultures. AMF diversity and community composition strongly depended on soil type and land use intensity, and several AMF species were characteristic for a specific soil type or a specific land use type and hence had a specific niche. In contrast, other AM fungi could be considered as ‘generalists’ as they were present in each soil type investigated, irrespective of land use intensity. An estimated 53% of the 61 observed AMF species could be classified as ‘specialists’ as (almost) exclusively found in specific soil types and/or under specific land use intensities; 28% appeared to be ‘generalists’ and 19% could not be classified. Plant species compositions (either natural or planted) had only a subordinate influence on the AMF communities. In conclusion, land use intensity and soil type strongly affected AMF community composition as well as the presence and prevalence of many AM fungi. Future work should examine how the differences in AMF species compositions affect important ecosystem processes in different soils and to which extent the loss of specific groups of AM fungi affect soil quality.
    Soil Biology & Biochemistry - SOIL BIOL BIOCHEM. 01/2010; 42(5):724-738.
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    C Castillo, R Rubio, F Borie, E Sieverding
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    ABSTRACT: The diversity of arbuscular mycorrhizal (AM) fungi in six Capsicum annuum or Lycopersicum escuíentum L. horticultural production systems of small farmers, and of two wheat agrosystems was comparatively investigated in Southern Chile (La Araucania). Soils in this region are mostly originated by volcanic ashes which are characterized by high organic matter content and high P-fixing capacity. Arbuscular mycorrhizal fungal symbioses are playing a key role for P uptake by horticultural crops grown there. The objective of this study was to determine AM fungal communities in cropping systems and to identify soil factors affecting their frequency and diversity. Of the totally 32 AM fungal species identified, 5 to 21 AM fungi species were found in horticultural locations and 8 to 11 AM fungi species in conventional tillage (CT) and no-tillage (NT) agroecosystems. No relationships on AM fungal diversity with soil factors were found. In wheat based agrosystems fungal diversity was somewhat lower under CT than NT whereas no such relationships between diversity and intensity of land use could be generated from horticultural systems. It is concluded that it will be advisable for farmers to inoculate their horticultural crops with selected mycorrhizal inoculants during the nursery stage, as it cannot be predicted from the soil conditions whether the native AM fungal community is sufficient to sustain a stable horticultural production in the region.
    Journal of soil science and plant nutrition. 12/2009; 10(4):407-413.
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    ABSTRACT: 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 K(2)CO(3) 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.
    Environmental Microbiology 03/2009; 11(6):1548-61. · 6.24 Impact Factor
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    ABSTRACT: The aim of this study was to investigate sporulation dynamics of arbuscular mycorrhizal fungal (AMF) communities from agroecosystems differing in land use intensity in long-term experimental microcosms. These were set up with characteristic grassland plants (Lolium perenne, Trifolium pratense, Plantago lanceolata), and inoculated with soils from several grasslands and arable lands subjected to crop rotation or continuous monocropping. The microcosms were maintained under ambient light and temperature conditions over 3 years. A novel, localized sampling scheme was applied for attaining exclusively the newly formed spores at bimonthly intervals. Overall, 39 AMF species were detected by morphological spore identification. Some species were recovered from all sites, others exclusively from arable lands, or grasslands, or from all sites except under maize monocropping. Clear seasonal and successional AMF sporulation dynamics were revealed, implying different life strategies of different AMF species. A first group of Glomus spp., including G. mosseae, sporulated rapidly during the first season. A second group, including G. constrictum and G. fasciculatum, sporulated late in the first season and replaced the first group during subsequent seasons. A large third group, including G. invermaium, G. macrocarpum and G. sinuosum, sporulated much later, in the second or third season. Acaulospora, Archaeospora and Ambispora spp. sporulated mainly during spring and early summer, Scutellospora and Cetraspora spp. only in fall. While in the microcosms derived from arable lands, cumulative species numbers did not increase anymore after 2 years, the numbers still increased significantly in the microcosms from the grasslands indicating longer lasting periods of sporulation cycles. Remarkably, the arable land under organic farming produced the highest AMF species richness, even higher than the grasslands. In conclusion, AMF communities from distinct agro-ecosystems differed in species composition and seasonal and successional sporulation dynamics.
    Agriculture Ecosystems & Environment - AGR ECOSYST ENVIRON. 01/2009; 134(3):257-268.
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    ABSTRACT: Acaulospora alpina sp. nov. forms small (65-85 microm diam), dark yellow to orange-brown spores laterally on the neck of hyaline to subhyaline sporiferous saccules. The spores have a three-layered outer spore wall, a bi-layered middle wall and a three-layered inner wall. The surface of the second layer of the outer spore wall is ornamented, having regular, circular pits (1.5-2 microm diam) that are as deep as wide and truncated conical. A "beaded" wall layer as found in most other Acaulospora spp. is lacking. The spore morphology of A. alpina resembles that of A. paulinae but can be differentiated easily by the unique ornamentation with the characteristic pits and by the spore color. A key is presented summarizing the morphological differences among Acaulospora species with an ornamented outer spore wall. Partial DNA sequences of the ITS1, 5.8S subunit and ITS2 regions of ribosomal DNA show that A. alpina and A. paulinae are not closely related. Acaulospora lacunosa, which has similar color but has generally bigger spores, also has distinct rDNA sequences. Acaulospora alpina is a characteristic member of the arbuscular mycorrhizal fungal communities in soils with pH 3.5-6.5 in grasslands of the Swiss Alps at altitudes between 1800 and 2700 m above sea level. It is less frequent at 1300-1800 m above sea level, and it so far has not been found in the Alps below 1300 m or in the lowlands of Switzerland.
    Mycologia 01/2006; 98(2):286-94. · 2.11 Impact Factor
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    ABSTRACT: The vertical distribution of spores of arbuscular mycorrhizal fungi (AMF) was investigated in soil profiles of extensively and intensively managed agroecosystems, including two permanent grasslands, a vineyard and two continuously mono-cropped maize fields. The number of AMF spores decreased with increasing soil depth--most drastically in the grasslands and the vineyard--but there was a large diversity of AMF species even in the deepest soil layers (50-70 cm). This was particularly striking in the maize fields where the highest species numbers were found below ploughing depth. Some species sporulated mainly, or exclusively, in the deep soil layers, others mainly in the top layers. Soil samples were used to inoculate trap cultures. Up to 18 months after inoculation, there was no conspicuous difference in the species composition among the trap cultures representing different soil depths, and only a weak match to the species composition determined by analysis of field samples. Our results indicate that the AMF communities in deep soil layers are surprisingly diverse and different from the topsoil. Thus, deep soil layers should be included in studies to get a complete picture of AMF diversity.
    New Phytologist 02/2005; 165(1):273-83. · 6.74 Impact Factor
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    F. Oehl, D. Redecker, E. Sieverding
    01/2005;

Publication Stats

646 Citations
30.56 Total Impact Points

Institutions

  • 2004–2013
    • Hohenheim University
      • Institute of Plant Production and Agroecology in the Tropics and Subtropics
      Stuttgart, Baden-Württemberg, Germany
  • 2003–2006
    • Universität Basel
      • Botanical Institute
      Basel, BS, Switzerland