101
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Kranabetter JM, Durall DM, MacKenzie WH. Diversity and species distribution of ectomycorrhizal fungi along productivity gradients of a southern boreal forest. MYCORRHIZA 2009; 19:99-111. [PMID: 18941804 DOI: 10.1007/s00572-008-0208-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 10/09/2008] [Indexed: 05/26/2023]
Abstract
Coniferous forests with diverse ectomycorrhizal fungus (EMF) communities are associated with nutrient-poor, acidic soils but there is some debate whether EMF can be equally adapted to more productive, nitrogen-rich sites. We compared EMF species distribution and diversity along a replicated productivity gradient in a southern boreal forest of British Columbia (Canada). Roots from subalpine fir (Abies lasiocarpa) saplings of the understory were sampled and EMF species were identified by morphotypes supplemented with ITS rDNA analysis. There were significant changes in the distribution and abundance of 74 EMF species along the productivity gradient, with as little as 24% community similarity among contrasting sites. Species richness per plot increased asymptotically with foliar nitrogen concentrations of subalpine fir, demonstrating that many EMF species were well suited to soils with high rates of nitrogen mineralization. EMF species abundance in relation to site productivity included parabolic, negative linear, and positive exponential curves. Both multi-site and more narrowly distributed EMF were documented, and a diverse mix of mantle exploration types was present across the entire productivity gradient. The results demonstrate strong associations of EMF fungal species with edaphic characteristics, especially nitrogen availability, and a specialization in EMF communities that may contribute to the successful exploitation of such contrasting extremes in soil fertility by a single tree host.
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Affiliation(s)
- J M Kranabetter
- British Columbia Ministry of Forests and Range, 4300 North Road, Victoria, BC, Canada, V8Z 5J3.
| | - D M Durall
- University of British Columbia-Okanagan, 3333 University Way, Kelowna, BC, Canada, V1V 1V7
| | - W H MacKenzie
- British Columbia Ministry of Forests and Range, Bag 6000, Smithers, BC, Canada, V0J 2N0
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102
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Brock PM, Döring H, Bidartondo MI. How to know unknown fungi: the role of a herbarium. THE NEW PHYTOLOGIST 2008; 181:719-724. [PMID: 19076294 DOI: 10.1111/j.1469-8137.2008.02703.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The development of a universal approach to the identification of fungi from the environment is impeded by the limited number and narrow phylogenetic range of the named internal transcribed spacer DNA sequences available on GenBank. The goal here was to assess the potential impact of systematic DNA sequencing from a fungal herbarium collection. DNA sequences were generated from a diverse set of 279 specimens deposited at the fungal herbarium of the Royal Botanic Gardens at Kew (UK) and bioinformatic analyses were used to study their overlap with the public database. It is estimated that c. 70% of the herbarium taxonomic diversity is not yet represented in GenBank and that a further c. 10% of our sequences match solely to 'environmental samples' or fungi otherwise unidentified. Here it is shown that the unsampled diversity residing in fungal herbaria can substantially enlarge the coverage of GenBank's fully identified sequence pool to ameliorate the problem of environmental unknowns and to aid in the detection of truly novel fungi by molecular data.
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103
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Palmer JM, Lindner DL, Volk TJ. Ectomycorrhizal characterization of an American chestnut (Castanea dentata)-dominated community in Western Wisconsin. MYCORRHIZA 2008; 19:27-36. [PMID: 18807258 DOI: 10.1007/s00572-008-0200-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 08/28/2008] [Indexed: 05/26/2023]
Abstract
Circa 1900, a farmer from the eastern US planted 11 American chestnut (Castanea dentata) seeds on a newly established farm near West Salem in western Wisconsin. These trees were very successful, producing a large stand of over 6,000 trees. Since this area is well outside the natural range of chestnut, these trees remained free from chestnut blight until 1987. In the West Salem stand, chestnuts are the dominant species of a mixed forest community, reminiscent of the chestnut-oak ecosystems of pre-1900 Appalachia. To identify putative mycorrhizal associates of chestnut in this unique forest, our approach was twofold: (1) an extensive fruiting body survey was conducted for four seasons that yielded approximately 100 putative mycorrhizal species and (2) a belowground molecular approach was used to generate DNA sequences of the internal transcribed spacer region from ectomycorrhizae. Unexpectedly, chestnut did not appear to be the dominant underground ectomycorrhizal-forming plant species. This study highlights the need to identify the plant host species when conducting belowground molecular-based surveys and provides preliminary identification of ectomycorrhizal fungi associated with a disjunct stand of American chestnut.
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Affiliation(s)
- Jonathan M Palmer
- Department of Biology, University of Wisconsin-La Crosse, La Crosse, WI, 54601, USA.
- , 3465 Microbial Sciences, 1550 Linden Dr., Madison, WI, 53706, USA.
| | - Daniel L Lindner
- Center for Forest Mycology Research, USDA Forest Service, Madison, WI, 53706, USA
| | - Thomas J Volk
- Department of Biology, University of Wisconsin-La Crosse, La Crosse, WI, 54601, USA
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104
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Karst J, Marczak L, Jones MD, Turkington R. The mutualism-parasitism continuum in ectomycorrhizas: a quantitative assessment using meta-analysis. Ecology 2008; 89:1032-42. [PMID: 18481528 DOI: 10.1890/07-0823.1] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Context dependency is deemed to position the outcomes of species interactions along a continuum of mutualism to parasitism. Thus, it is imperative to understand which factors determine where a particular interspecific interaction falls along the continuum. Over the past 20 years research on the ectomycorrhizal symbiosis has resulted in sufficient independent studies to now generalize about the factors and mechanisms that affect host response to ectomycorrhizas. Using meta-analysis we quantitatively evaluated the role of biotic (partner identity and colonization levels of ectomycorrhizal fungi) and abiotic (phosphorus levels) factors in determining host biomass, height, and shoot:root responses to ectomycorrhizal associations. On average, seedlings across multiple host genera increased in total biomass when inoculated with ectomycorrhizal fungi regardless of the identity of the fungal associate; host genera differed in the magnitude of response for both total biomass and shoot:root ratio. Association with different fungal genera modified only host allocation of biomass to shoots and roots. Neither level of colonization on inoculated seedlings nor the level of contamination on control seedlings relative to colonization levels by target fungi on inoculated seedlings was important in explaining variation in effect sizes for any growth response. None of our proposed factors (identity of partners, colonization level, magnitude of contamination, or duration of association) explained variation in effect sizes for shoot height, although in general seedlings were taller when inoculated with ectomycorrhizal fungi. Phosphorus additions did not influence effect sizes. Although the general trend across studies was for a positive response of hosts to ectomycorrhizal inoculation, publication bias and methodological issues effectively reduce and distort the spectrum on which we evaluate host responses to ectomycorrhizal inoculation. Our results indicate that the variation in ectomycorrhizal fungi perceived by the host may be of a discrete (presence/absence of ectomycorrhizal fungi) rather than continuous nature (variation in identity or abundance of ectomycorrhizal fungi).
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Affiliation(s)
- Justine Karst
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, British Columbia V6T 1Z4, Canada.
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105
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Carriconde F, Gardes M, Jargeat P, Heilmann-Clausen J, Mouhamadou B, Gryta H. Population evidence of cryptic species and geographical structure in the cosmopolitan ectomycorrhizal fungus, Tricholoma scalpturatum. MICROBIAL ECOLOGY 2008; 56:513-524. [PMID: 18305983 DOI: 10.1007/s00248-008-9370-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 12/17/2007] [Accepted: 01/30/2008] [Indexed: 05/26/2023]
Abstract
Tricholoma scalpturatum is an ectomycorrhizal fungus that forms symbioses with roots of diverse trees and shrubs. It is commonly encountered in a wide range of habitats, across temperate ecosystems. A previous study has revealed a high genetic diversity at a local scale, and ruderal abilities. To examine genetic structure at a large geographical scale, a total of 164 basidiocarps were collected from 30 populations located in Western Europe, from Spain to Scandinavia. These samples were analyzed by three molecular methods with different levels of resolution: inter-simple sequence repeats (ISSRs), restriction fragment length polymorphisms (RFLPs) in the rDNA internal transcribed spacer (ITS), and ITS sequence analysis. Considerable genetic variation was found, and the morphospecies was separated into two genetic groups that were distinct from each other. The ISSR data and the relatively low percentage value (96%) of shared sequence polymorphisms in the ITS between isolates from the two groups, strongly suggest cryptic species and long-lasting separation. No geographical exclusion was detected for these two widely distributed taxa. However, high estimates of population differentiation were observed in each group, including between populations less than a few kilometers apart. This result provides evidence for limited gene flow and/or founding effects. It also indicates that T. scalpturatum does not constitute a random mating population, and the hypothesis of endemism cannot be excluded for this cosmopolitan wind-dispersed fungus.
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Affiliation(s)
- Fabian Carriconde
- Laboratoire Evolution et Diversité Biologique, UMR 5174 CNRS-UPS-ENFA, Bât. 4R3, Université Paul Sabatier-Toulouse III, 118 route de Narbonne, 31062, Toulouse Cedex 9, France.
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106
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Peay KG, Kennedy PG, Bruns TD. Fungal Community Ecology: A Hybrid Beast with a Molecular Master. Bioscience 2008. [DOI: 10.1641/b580907] [Citation(s) in RCA: 216] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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107
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Morris MH, Pérez-Pérez MA, Smith ME, Bledsoe CS. Multiple species of ectomycorrhizal fungi are frequently detected on individual oak root tips in a tropical cloud forest. MYCORRHIZA 2008; 18:375-383. [PMID: 18704515 DOI: 10.1007/s00572-008-0186-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 07/01/2008] [Indexed: 05/26/2023]
Abstract
The ecological importance of ectomycorrhizal (EM) fungi in tropical ecosystems is increasingly recognized, but few studies have used molecular methods to examine EM fungal communities in tropical forests. The diversity and composition of the EM community on Quercus crassifolia in a tropical montane cloud forest in southern Mexico were characterized using DNA sequencing of single root tips. Individual root tips commonly harbored multiple fungal species that resulted in mixed polymerase chain reaction (PCR) products. By cloning and performing gel extractions on mixed PCR samples, we identified two or more EM fungi on 26% of the root tips. When non-EM fungi were considered, this figure increased to 31% of root tips. A total of 44 EM taxa and nine non-EM taxa were detected on roots from 21 soil cores (104 root tips). Taxa in the families Russulaceae, Cortinariaceae, Inocybaceae, and Thelephoraceae were frequent. This is the first study to characterize the belowground EM community in a tropical montane cloud forest.
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Affiliation(s)
- Melissa H Morris
- Department of Land, Air and Water Resources, University of California, Davis, CA, 95616, USA.
| | - Miguel A Pérez-Pérez
- Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Morelia, 58190, Michoacán, México
| | - Matthew E Smith
- Department of Organismic and Evolutionary Biology and the Farlow Herbarium, Harvard University, Cambridge, MA, 02138, USA
| | - Caroline S Bledsoe
- Department of Land, Air and Water Resources, University of California, Davis, CA, 95616, USA
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108
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Urban A, Puschenreiter M, Strauss J, Gorfer M. Diversity and structure of ectomycorrhizal and co-associated fungal communities in a serpentine soil. MYCORRHIZA 2008; 18:339-354. [PMID: 18677625 DOI: 10.1007/s00572-008-0189-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 07/09/2008] [Indexed: 05/26/2023]
Abstract
The community of ectomycorrhizal (ECM) and co-associated fungi from a serpentine site forested with Pinus sylvestris and Quercus petraea was explored, to improve the understanding of ECM diversity in naturally metalliferous soils. ECM fungi were identified by a combination of morphotyping and direct sequencing of the nuclear ribosomal internal transcribed spacer region 2 and of a part of the large-subunit region. Co-associated fungi from selected ECM were identified by restriction fragment length polymorphism and sequencing of representative clones from libraries. Polymerase chain reaction with species-specific primers was applied to assess patterns of association of ECM and co-associated fungi. Twenty ECM species were differentiated. Aphyllophoralean fungi representing several basidiomycete orders and Russulaceae were dominant. Phialocephala fortinii was the most frequently encountered taxon from the diverse assemblage of ECM co-associated fungi. A ribotype representing a deeply branching ascomycete lineage known from ribosomal deoxyribonucleic acid sequences only was detected in some ECM samples. A broad taxonomic range of fungi have the potential to successfully colonise tree roots under the extreme edaphic conditions of serpentine soils. Distribution patterns of ECM-co-associated fungi hint at the importance of specific inter-fungal interactions, which are hypothesised to be a relevant factor for the maintenance of ECM diversity.
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Affiliation(s)
- Alexander Urban
- Fungal Genomics Unit, Austrian Research Centers, Tech Gate Vienna, Donau-City-Strasse 1, 1220 Vienna, Austria.
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109
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Courty PE, Franc A, Pierrat JC, Garbaye J. Temporal changes in the ectomycorrhizal community in two soil horizons of a temperate oak forest. Appl Environ Microbiol 2008; 74:5792-801. [PMID: 18658284 PMCID: PMC2547048 DOI: 10.1128/aem.01592-08] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Accepted: 07/11/2008] [Indexed: 11/20/2022] Open
Abstract
The species structure of an ectomycorrhizal (ECM) community was assessed monthly for 15 months in the two horizons (A1 and A2) of an oak temperate forest in northeastern France. Ectomycorrhizal species were identified each month by internal transcribed spacer sequencing. Seventy-five fungal symbionts were identified. The community was dominated by Tomentellaceae, Russulaceae, Cortinariaceae, and Boletales. Four species are abundant in the study site: Lactarius quietus, Tomentella sublilacina, Cenococcum geophilum, and Russula sp1. The relative abundance of each species varied depending on the soil horizon and over time. Some species, such as L. quietus, were present in the A1 and A2 horizons. C. geophilum was located particularly in the A2 horizon, whereas T. sublilacina was more abundant in A1. Some species, such as Clavulina sp., were detected in winter, while T. sublilacina and L. quietus were present all year long. Our results support the hypothesis that a rapid turnover of species composition of the ECM community occurs over the course of a month. The spatial and temporal unequal distribution of ECM species could be explained by their ecological preferences, driven by such factors as root longevity, competition for resources, and resistance to environmental variability.
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Affiliation(s)
- Pierre-Emmanuel Courty
- UMR 1136 INRA-Nancy Université, Interactions Arbres/Micro-organisms, INRA-Nancy, 54280 Champenoux, France.
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110
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Nilsson RH, Kristiansson E, Ryberg M, Hallenberg N, Larsson KH. Intraspecific ITS variability in the kingdom fungi as expressed in the international sequence databases and its implications for molecular species identification. Evol Bioinform Online 2008; 4:193-201. [PMID: 19204817 PMCID: PMC2614188 DOI: 10.4137/ebo.s653] [Citation(s) in RCA: 546] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The internal transcribed spacer (ITS) region of the nuclear ribosomal repeat unit is the most popular locus for species identification and subgeneric phylogenetic inference in sequence-based mycological research. The region is known to show certain variability even within species, although its intraspecific variability is often held to be limited and clearly separated from interspecific variability. The existence of such a divide between intra- and interspecific variability is implicitly assumed by automated approaches to species identification, but whether intraspecific variability indeed is negligible within the fungal kingdom remains contentious. The present study estimates the intraspecific ITS variability in all fungi presently available to the mycological community through the international sequence databases. Substantial differences were found within the kingdom, and the results are not easily correlated to the taxonomic affiliation or nutritional mode of the taxa considered. No single unifying yet stringent upper limit for intraspecific variability, such as the canonical 3% threshold, appears to be applicable with the desired outcome throughout the fungi. Our results caution against simplified approaches to automated ITS-based species delimitation and reiterate the need for taxonomic expertise in the translation of sequence data into species names.
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Affiliation(s)
- R Henrik Nilsson
- Department of Plant and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden.
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111
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Ryberg M, Nilsson RH, Kristiansson E, Töpel M, Jacobsson S, Larsson E. Mining metadata from unidentified ITS sequences in GenBank: a case study in Inocybe (Basidiomycota). BMC Evol Biol 2008; 8:50. [PMID: 18282272 PMCID: PMC2275786 DOI: 10.1186/1471-2148-8-50] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2007] [Accepted: 02/18/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The lack of reference sequences from well-identified mycorrhizal fungi often poses a challenge to the inference of taxonomic affiliation of sequences from environmental samples, and many environmental sequences are thus left unidentified. Such unidentified sequences belonging to the widely distributed ectomycorrhizal fungal genus Inocybe (Basidiomycota) were retrieved from GenBank and divided into species that were identified in a phylogenetic context using a reference dataset from an ongoing study of the genus. The sequence metadata of the unidentified Inocybe sequences stored in GenBank, as well as data from the corresponding original papers, were compiled and used to explore the ecology and distribution of the genus. In addition, the relative occurrence of Inocybe was contrasted to that of other mycorrhizal genera. RESULTS Most species of Inocybe were found to have less than 3% intraspecific variability in the ITS2 region of the nuclear ribosomal DNA. This cut-off value was used jointly with phylogenetic analysis to delimit and identify unidentified Inocybe sequences to species level. A total of 177 unidentified Inocybe ITS sequences corresponding to 98 species were recovered, 32% of which were successfully identified to species level in this study. These sequences account for an unexpectedly large proportion of the publicly available unidentified fungal ITS sequences when compared with other mycorrhizal genera. Eight Inocybe species were reported from multiple hosts and some even from hosts forming arbutoid or orchid mycorrhizae. Furthermore, Inocybe sequences have been reported from four continents and in climate zones ranging from cold temperate to equatorial climate. Out of the 19 species found in more than one study, six were found in both Europe and North America and one was found in both Europe and Japan, indicating that at least many north temperate species have a wide distribution. CONCLUSION Although DNA-based species identification and circumscription are associated with practical and conceptual difficulties, they also offer new possibilities and avenues for research. Metadata assembly holds great potential to synthesize valuable information from community studies for use in a species and taxonomy-oriented framework.
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Affiliation(s)
- Martin Ryberg
- Department of Plant and Environmental Sciences, Göteborg University, Box 461, 405 30 Göteborg, Sweden
| | - R Henrik Nilsson
- Department of Plant and Environmental Sciences, Göteborg University, Box 461, 405 30 Göteborg, Sweden
| | - Erik Kristiansson
- Department of Mathematical Statistics, Chalmers University of Technology, Göteborg, Sweden
| | - Mats Töpel
- Department of Plant and Environmental Sciences, Göteborg University, Box 461, 405 30 Göteborg, Sweden
| | - Stig Jacobsson
- Department of Plant and Environmental Sciences, Göteborg University, Box 461, 405 30 Göteborg, Sweden
| | - Ellen Larsson
- Department of Plant and Environmental Sciences, Göteborg University, Box 461, 405 30 Göteborg, Sweden
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112
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Morris MH, Smith ME, Rizzo DM, Rejmánek M, Bledsoe CS. Contrasting ectomycorrhizal fungal communities on the roots of co-occurring oaks (Quercus spp.) in a California woodland. THE NEW PHYTOLOGIST 2008; 178:167-176. [PMID: 18194145 DOI: 10.1111/j.1469-8137.2007.02348.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plant host species is considered an important factor influencing ectomycorrhizal (EM) communities. To gain insights into the role of host species in structuring EM communities, EM communities on sympatric oak (Quercus) species were compared in the Sierra Nevada foothills of California. Using molecular methods (polymerase chain reaction, cloning, restriction fragment length polymorphism and DNA sequencing), EM fungi on roots of deciduous Quercus douglasii and evergreen Quercus wislizeni trees were identified from 64 soil cores. The total EM species richness was 140, of which 40 taxa were detected on both oak hosts. Greater diversity and frequency of EM fungi with epigeous fruiting habit were found on Q. wislizeni, while taxa in the Ascomycota were more frequent and diverse on Q. douglasii. Using ordination, it was determined that both soil extractable phosphorus and oak host species explained a significant proportion of the variation in EM species distribution. These results indicate that plant host species can be an important factor influencing EM fungal community composition, even within congeneric trees.
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Affiliation(s)
| | | | | | - Marcel Rejmánek
- Section of Evolution and Ecology, University of California, Davis, CA 95616, USA
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113
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Tedersoo L, Jairus T, Horton BM, Abarenkov K, Suvi T, Saar I, Kõljalg U. Strong host preference of ectomycorrhizal fungi in a Tasmanian wet sclerophyll forest as revealed by DNA barcoding and taxon-specific primers. THE NEW PHYTOLOGIST 2008; 180:479-490. [PMID: 18631297 DOI: 10.1111/j.1469-8137.2008.02561.x] [Citation(s) in RCA: 251] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Ectomycorrhizal (ECM) symbiosis is a widespread plant nutrition strategy in Australia, especially in semiarid regions. This study aims to determine the diversity, community structure and host preference of ECM fungi in a Tasmanian wet sclerophyll forest. Ectomycorrhizal fungi were identified based on anatomotyping and rDNA internal transcribed spacer (ITS)-large subunit (LSU) sequence analysis using taxon-specific primers. Host tree roots were identified based on root morphology and length differences of the chloroplast trnL region. A total of 123 species of ECM fungi were recovered from root tips of Eucalyptus regnans (Myrtaceae), Pomaderris apetala (Rhamnaceae) and Nothofagus cunninghamii (Nothofagaceae). The frequency of two thirds of the most common ECM fungi from several lineages was significantly influenced by host species. The lineages of Cortinarius, Tomentella-Thelephora, Russula-Lactarius, Clavulina, Descolea and Laccaria prevailed in the total community and their species richness and relative abundance did not differ by host species. This study demonstrates that strongly host-preferring, though not directly specific, ECM fungi may dominate the below-ground community. Apart from the richness of Descolea, Tulasnella and Helotiales and the lack of Suillus-Rhizopogon and Amphinema-Tylospora, the ECM fungal diversity and phylogenetic community structure is similar to that in the Holarctic realm.
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Affiliation(s)
- Leho Tedersoo
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, EST-51005 Tartu, Estonia
- Natural History Museum, University of Tartu, 46 Vanemuise Street, EST-51005 Tartu, Estonia
| | - Teele Jairus
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, EST-51005 Tartu, Estonia
- Natural History Museum, University of Tartu, 46 Vanemuise Street, EST-51005 Tartu, Estonia
| | - Bryony M Horton
- Schools of Agricultural Science and Plant Science, University of Tasmania, Hobart, 7001, Tasmania, Australia
| | - Kessy Abarenkov
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, EST-51005 Tartu, Estonia
| | - Triin Suvi
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, EST-51005 Tartu, Estonia
| | - Irja Saar
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, EST-51005 Tartu, Estonia
| | - Urmas Kõljalg
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, EST-51005 Tartu, Estonia
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114
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He XH, Horwath WR, Zasoski RJ, Aanderud Z, Bledsoe CS. Nitrogen sink strength of ectomycorrhizal morphotypes of Quercus douglasii, Q. garryana, and Q. agrifolia seedlings grown in a northern California oak woodland. MYCORRHIZA 2007; 18:33-41. [PMID: 17899217 DOI: 10.1007/s00572-007-0150-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Accepted: 08/17/2007] [Indexed: 05/17/2023]
Abstract
Little information is known on what the magnitude of nitrogen (N) processed by ectomycorrhizal (ECM) fungal species in the field. In a common garden experiment performed in a northern California oak woodland, we investigated transfer of nitrogen applied as 15NH4 or 15NO3 from leaves to ectomycorrhizal roots of three oak species, Quercus agrifolia, Q. douglasii, and Q. garryana. Oak seedlings formed five common ectomycorrhizal morphotypes on root tips. Mycorrhizal tips were more enriched in 15N than fine roots. N transfer was greater to the less common morphotypes than to the more common types. 15N transfer from leaves to roots was greater when 15NO3(-), not [Formula: see text], was supplied. 15N transfer to roots was greater in seedlings of Q. agrifolia than in Q. douglasii and Q. garryana. Differential N transfer to ectomycorrhizal root tips suggests that ectomycorrhizal morphotypes can influence flows of N from leaves to roots and that mycorrhizal diversity may influence the total N requirement of plants.
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Affiliation(s)
- X H He
- Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, CA, 95616, USA
- Asian National Environmental Science Center, University of Tokyo, 1-1-8 Midori-cho, Nishitokyo, Tokyo, 188-0002, Japan
| | - W R Horwath
- Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - R J Zasoski
- Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Z Aanderud
- Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - C S Bledsoe
- Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, CA, 95616, USA.
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115
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Smith ME, Douhan GW, Rizzo DM. Intra-specific and intra-sporocarp ITS variation of ectomycorrhizal fungi as assessed by rDNA sequencing of sporocarps and pooled ectomycorrhizal roots from a Quercus woodland. MYCORRHIZA 2007; 18:15-22. [PMID: 17710446 DOI: 10.1007/s00572-007-0148-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Accepted: 07/19/2007] [Indexed: 05/16/2023]
Abstract
The Internal Transcribed Spacer (ITS) regions of ribosomal DNA are widely used as markers for phylogenetic analyses and environmental sampling from a variety of organisms including fungi, plants, and animals. In theory, concerted evolution homogenizes multicopy genes so that little or no variation exists within populations or individuals. However, contrary to theory, ITS variation has been confirmed in populations and individuals from a diverse range of eukaryotes. The presence of intraspecific and intra-individual variation in multicopy genes has important implications for ecological and phylogenetic studies, yet relatively little is known about natural variation of these genes, particularly at the community level. In this study, we examined intraspecific and intra-sporocarp ITS variation by DNA sequencing from sporocarps and pooled roots from 68 species of ectomycorrhizal fungi collected at a single site in a Quercus woodland. We detected ITS variation in 27 species, roughly 40% of the taxa examined. Although intraspecific ITS variation was generally low (0.16-2.85%, mean = 0.74%), it was widespread within this fungal community. We detected ITS variation in both sporocarps and ectomycorrhizal roots, and variation was present within species of Ascomycota and Basidiomycota, two distantly related lineages within the Fungi. We discuss the implications of such widespread ITS variability with special reference to DNA-based environmental sampling from diverse fungal communities.
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Affiliation(s)
- Matthew E Smith
- Department of Organismic and Evolutionary Biology and the Farlow Herbarium, Harvard University, 20 Divinity Avenue, Cambridge, MA, 02138, USA.
| | - Greg W Douhan
- Department of Plant Pathology and Microbiology, University of California at Riverside, Riverside, CA, 92521, USA
| | - David M Rizzo
- Department of Plant Pathology, University of California at Davis, Davis, CA, 95616, USA
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116
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Widespread occurrence and phylogenetic placement of a soil clone group adds a prominent new branch to the fungal tree of life. Mol Phylogenet Evol 2007; 46:635-44. [PMID: 18032071 DOI: 10.1016/j.ympev.2007.10.002] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 09/28/2007] [Accepted: 10/06/2007] [Indexed: 11/23/2022]
Abstract
Fungi are one of the most diverse groups of Eukarya and play essential roles in terrestrial ecosystems as decomposers, pathogens and mutualists. This study unifies disparate reports of unclassified fungal sequences from soils of diverse origins and anchors many of them in a well-supported clade of the Ascomycota equivalent to a subphylum. We refer to this clade as Soil Clone Group I (SCGI). We expand the breadth of environments surveyed and develop a taxon-specific primer to amplify 2.4kbp rDNA fragments directly from soil. Our results also expand the known range of this group from North America to Europe and Australia. The ancient origin of SCGI implies that it may represent an important transitional form among the basal Ascomycota groups. SCGI is unusual because it currently represents the only major fungal lineage known only from sequence data. This is an important contribution towards building a more complete fungal phylogeny and highlights the need for further work to determine the function and biology of SCGI taxa.
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117
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Manter DK, Vivanco JM. Use of the ITS primers, ITS1F and ITS4, to characterize fungal abundance and diversity in mixed-template samples by qPCR and length heterogeneity analysis. J Microbiol Methods 2007; 71:7-14. [PMID: 17683818 DOI: 10.1016/j.mimet.2007.06.016] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 06/25/2007] [Accepted: 06/25/2007] [Indexed: 11/28/2022]
Abstract
Molecular-based approaches to assess microbial biomass and diversity from soil and other ecosystems are rapidly becoming the standard methodology for analysis. While these techniques are advantageous, because they do not rely on the need to culture organisms, each technique may have its own biases and/or limitations when used to assess fungal diversity from mixed-template samples. In this study, we analyzed PCR specificity and efficiency of the ITS primers (ITS1F and ITS4) in a series of single- and mixed-template samples using a combined quantitative PCR-length heterogeneity analysis (LH-qPCR) approach. As expected, these primers successfully amplified all higher fungal species tested (10 ascomycetes, 6 basidiomycetes, and 4 zygomycetes) and no members of the oomycetes. Based on our results, and a search of the GenBank database, amplicons of the ITS1F and ITS4 primer set exhibit considerable variability (420 to 825 bp), but due to similarities in amplicon sizes of some fungal species, actual species diversity in environmental samples may be underestimated approximately two-fold. The addition of an initial qPCR step allowed for the accurate quantitation of total fungal DNA in mixed-template samples over five orders of magnitude (10(-)(1) to 10(3) pg microl(-)(1)). PCR biases between individuals in mixed-templates rendered it impossible to determine the absolute quantity of any individual within a population from its individual peak height. However, relative changes in individuals within a mixed-template sample could be determined due to a constant proportionality between peak heights and starting template concentration. Variability associated with the individual steps of the LH-qPCR analysis was also determined from environmental samples.
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Affiliation(s)
- Daniel K Manter
- USDA-ARS, Soil-Plant-Nutrient Research Unit, Ft. Collins, CO, United States.
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118
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Abstract
Ectomycorrhizal (ECM) fungi form mutualistic symbioses with many tree species and are regarded as key organisms in nutrient and carbon cycles in forest ecosystems. Our appreciation of their roles in these processes is hampered by a lack of understanding of their soil-borne mycelial systems. These mycelia represent the vegetative thalli of ECM fungi that link carbon-yielding tree roots with soil nutrients, yet we remain largely ignorant of their distribution, dynamics and activities in forest soils. In this review we consider information derived from investigations of fruiting bodies, ECM root tips and laboratory-based microcosm studies, and conclude that these provide only limited insights into soil-borne ECM mycelial communities. Recent advances in understanding soil-borne mycelia of ECM fungi have arisen from the combined use of molecular technologies and novel field experimentation. These approaches have the potential to provide unprecedented insights into the functioning of ECM mycelia at the ecosystem level, particularly in the context of land-use changes and global climate change.
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119
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Smith ME, Douhan GW, Rizzo DM. Ectomycorrhizal community structure in a xeric Quercus woodland based on rDNA sequence analysis of sporocarps and pooled roots. THE NEW PHYTOLOGIST 2007; 174:847-863. [PMID: 17504467 DOI: 10.1111/j.1469-8137.2007.02040.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Quercus woodlands are key components of California's wild landscapes, yet little is known about ectomycorrhizal (EM) fungi in these ecosystems. We examined the EM community associated with Quercus douglasii using sporocarp surveys and by pooling EM roots and subjecting them to DNA extraction, polymerase chain reaction (PCR), cloning, restriction fragment length polymorphism (RFLP) screening and DNA sequencing. Ectomycorrhizal root symbionts were sampled four times in 2003-04. During this time, the below-ground community structure was relatively stable; we found no evidence of taxa adapted to winter or spring conditions and only one species varied widely in occurrence between years. The EM community from sporocarps and roots was diverse (161 species), rich in Ascomycota (46 species), and dominated by fungi with cryptic sporocarps. This included a large number of resupinate and hypogeous taxa, many of which were detected both above- and below-ground.
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Affiliation(s)
- Matthew E Smith
- Department of Plant Pathology, University of California at Davis, Davis CA 95616, USA
| | - Greg W Douhan
- Department of Plant Pathology, University of California at Davis, Davis CA 95616, USA
- Department of Plant Pathology, University of California at Riverside, Riverside CA 92521, USA
| | - David M Rizzo
- Department of Plant Pathology, University of California at Davis, Davis CA 95616, USA
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120
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Affiliation(s)
- Ian A Dickie
- Landcare Research, PO Box 40, Lincoln 7640, New Zealand (tel +64 3 321 9646; fax +64 3321 9998; email )
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121
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Twieg BD, Durall DM, Simard SW. Ectomycorrhizal fungal succession in mixed temperate forests. THE NEW PHYTOLOGIST 2007; 176:437-447. [PMID: 17888121 DOI: 10.1111/j.1469-8137.2007.02173.x] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Ectomycorrhizal (ECM) fungal communities of Douglas-fir (Pseudotsuga menziesii) and paper birch (Betula papyrifera) were studied along a chronosequence of forest development after stand-replacing disturbance. Previous studies of ECM succession did not use molecular techniques for fungal identification or lacked replication, and none examined different host species. Four age classes of mixed forests were sampled: 5-, 26-, 65-, and 100-yr-old, including wildfire-origin stands from all four classes and stands of clearcut origin from the youngest two classes. Morphotyping and DNA sequences were used to identify fungi on ECM root tips. ECM fungal diversities were lower in 5-yr-old than in older stands on Douglas-fir, but were similar among age classes on paper birch. Host-specific fungi dominated in 5-yr-old stands, but host generalists were dominant in the oldest two age classes. ECM fungal community compositions were similar in 65- and 100-yr-old stands but differed among all other pairs of age classes. Within the age range studied, site-level ECM fungal diversity reached a plateau by the 26-yr-old age class, while community composition stabilized by the 65-yr-old class. Simple categories such as 'early stage', 'multi stage', and 'late stage' were insufficient to describe fungal species' successional patterns. Rather, ECM fungal succession may be best described in the context of stand development.
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Affiliation(s)
- Brendan D Twieg
- Department of Biology and Physical Geography, University of British Columbia Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 Canada
| | - Daniel M Durall
- Department of Biology and Physical Geography, University of British Columbia Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 Canada
| | - Suzanne W Simard
- Department of Forest Sciences, University of British Columbia Vancouver, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4 Canada
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122
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Koide RT, Courty PE, Garbaye J. Research perspectives on functional diversity in ectomycorrhizal fungi. THE NEW PHYTOLOGIST 2007; 174:240-243. [PMID: 17388886 DOI: 10.1111/j.1469-8137.2007.01987.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Affiliation(s)
- Roger T Koide
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802 USA
| | - Pierre-Emmanuel Courty
- INRA Nancy, UMR 1136 INRA/UHP Interactions Arbres-Microorganismes, 54280 Champenoux, France
| | - Jean Garbaye
- INRA Nancy, UMR 1136 INRA/UHP Interactions Arbres-Microorganismes, 54280 Champenoux, France
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123
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Nilsson RH, Ryberg M, Kristiansson E, Abarenkov K, Larsson KH, Kõljalg U. Taxonomic reliability of DNA sequences in public sequence databases: a fungal perspective. PLoS One 2006; 1:e59. [PMID: 17183689 PMCID: PMC1762357 DOI: 10.1371/journal.pone.0000059] [Citation(s) in RCA: 380] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Accepted: 10/26/2006] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND DNA sequences are increasingly seen as one of the primary information sources for species identification in many organism groups. Such approaches, popularly known as barcoding, are underpinned by the assumption that the reference databases used for comparison are sufficiently complete and feature correctly and informatively annotated entries. METHODOLOGY/PRINCIPAL FINDINGS The present study uses a large set of fungal DNA sequences from the inclusive International Nucleotide Sequence Database to show that the taxon sampling of fungi is far from complete, that about 20% of the entries may be incorrectly identified to species level, and that the majority of entries lack descriptive and up-to-date annotations. CONCLUSIONS The problems with taxonomic reliability and insufficient annotations in public DNA repositories form a tangible obstacle to sequence-based species identification, and it is manifest that the greatest challenges to biological barcoding will be of taxonomical, rather than technical, nature.
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Affiliation(s)
- R Henrik Nilsson
- Department of Plant and Environmental Sciences, Göteborg University, Sweden.
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124
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Tedersoo L, Suvi T, Larsson E, Kõljalg U. Diversity and community structure of ectomycorrhizal fungi in a wooded meadow. ACTA ACUST UNITED AC 2006; 110:734-48. [PMID: 16769208 DOI: 10.1016/j.mycres.2006.04.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 02/13/2006] [Accepted: 02/16/2006] [Indexed: 10/24/2022]
Abstract
Wooded meadows are seminatural plant communities that support high diversity of various taxa. Due to changes in land use, wooded meadows have severely declined during the last century. The dominant trees in wooded meadows acquire mineral nutrients via ectomycorrhizal fungi. Using anatomotyping and sequencing of root tips, interpolation and extrapolation methods, we studied the diversity and community structure of ectomycorrhizal fungi in two soil horizons of both managed and forested parts of a wooded meadow in Estonia. Species of Thelephoraceae, Sebacinaceae and the genus Inocybe dominated the whole ectomycorrhizal fungal community of 172 observed species. Forested and managed parts of the wooded meadow harboured different communities of ectomycorrhizal fungi, whereas soil horizon had a negligible effect on the fungal community composition. Diverse soil conditions and host trees likely support the high richness of ectomycorrhizal fungi in the wooded meadow ecosystem. Direct sequencing integrated with interpolation and extrapolation methods are promising to identify the fungi at the species level and to compare species richness between communities of ectomycorrhizal fungi.
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Affiliation(s)
- Leho Tedersoo
- Institute of Botany and Ecology, University of Tartu, 40 Lai Str., 51005 Tartu, Estonia.
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125
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Baier R, Ingenhaag J, Blaschke H, Göttlein A, Agerer R. Vertical distribution of an ectomycorrhizal community in upper soil horizons of a young Norway spruce (Picea abies [L.] Karst.) stand of the Bavarian Limestone Alps. MYCORRHIZA 2006; 16:197-206. [PMID: 16518613 DOI: 10.1007/s00572-006-0035-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2005] [Accepted: 01/05/2006] [Indexed: 05/07/2023]
Abstract
The vertical niche differentiation of genera of ectomycorrhiza (ECM) was assessed in a 17-year-old Norway spruce (Picea abies [L.] Karst.) plantation on a mountainous dolomitic site (1,050 m above sea level) of the Bavarian Limestone Alps. We determined ECM anatomotypes, recorded the abundance of corresponding ECM root tips and classified them into groups of ECM exploration types, which refer to the organisation and the extent of their extramatrical mycelia. The abundance of ECM was highest in the organic soil layers, compared to the mineral soil horizon. The ordination of the ECM communities and of the exploration types revealed segregation related to soil horizon properties. While Cenococcum geophilum preferred the organic soil layers, Lactarius spp., Tomentella spp. and Craterellus tubaeformis were generally most abundant in the mineral soil horizons. Cenococcum geophilum was the predominant species, possibly based on enhanced competitiveness under the prevailing site conditions. The short-distance exploration types (e.g. C. geophilum) preferentially colonised the organic soil layer, whereas the contact types (e.g. most of the Tomentella spp., C. tubaeformis) together with medium-distance types (e.g. Amphinema byssoides) were primarily associated with the underlying A-horizons. Therefore, the soil horizons had an important effect on the distribution of ECM and on their community structure. The spatial niche differentiation of ECM genera and exploration types is discussed in regard to specific physico-chemical properties of soil horizon and the assumed ecophysiological strategies of ECM.
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Affiliation(s)
- Roland Baier
- Department of Ecology, Forest Nutrition and Water Resources, Technische Universität München, 85354, Freising, Germany.
- Fachgebiet Waldernährung und Wasserhaushalt, Am Hochanger 13, D-85354, Freising, Germany.
| | - Jan Ingenhaag
- Faculty of Biology, Department of Biology I, Mycological Biodiversity, Ludwig-Maximilians-Universität München, 80638, München, Germany
| | - Helmut Blaschke
- Department of Ecology, Plant Ecophysiology, Technische Universität München, 85354, Freising, Germany
| | - Axel Göttlein
- Department of Ecology, Forest Nutrition and Water Resources, Technische Universität München, 85354, Freising, Germany
| | - Reinhard Agerer
- Faculty of Biology, Department of Biology I, Mycological Biodiversity, Ludwig-Maximilians-Universität München, 80638, München, Germany
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126
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Korkama T, Pakkanen A, Pennanen T. Ectomycorrhizal community structure varies among Norway spruce (Picea abies) clones. THE NEW PHYTOLOGIST 2006; 171:815-24. [PMID: 16918552 DOI: 10.1111/j.1469-8137.2006.01786.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In northern boreal forests, the diversity of ectomycorrhizal (ECM) species is much greater than that of their host trees. This field study investigated the role of individual trees in shaping the ECM community. We compared ECM communities of eight Norway spruce (Picea abies) clones planted in a clear-cut area in 1994 with a randomized block design. In 2003, the ECM fungi were identified from randomly sampled root tips using denaturing gradient gel electrophoresis (DGGE) and rDNA internal transcribed spacer (ITS) sequence similarity. ECM diversity varied among clone groups, showing twofold growth differences. Moreover, according to detrended correspondence analysis (DCA), ECM community structure varied not only among but also within slow-growing or fast-growing clones. Results suggest that ECM diversity and community structure are related to the growth rate or size of the host. A direct or indirect influence of host genotype was also observed, and we therefore suggest that individual trees are partly responsible for the high diversity and patchy distribution of ECM communities in boreal forests.
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Affiliation(s)
- T Korkama
- Finnish Forest Research Institute (Metla) Vantaa Research Unit, PO Box 18, FI-01301, Vantaa, Finland.
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127
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Tedersoo L, Hansen K, Perry BA, Kjøller R. Molecular and morphological diversity of pezizalean ectomycorrhiza. THE NEW PHYTOLOGIST 2006; 170:581-96. [PMID: 16626478 DOI: 10.1111/j.1469-8137.2006.01678.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A growing body of molecular research is discovering a high diversity of pezizalean ectomycorrhiza (EcM), yet most remain unidentified at the genus or species level. This study describes EcM-forming taxa within the Pezizales. EcM-forming Pezizales were revealed by morphotyping and sequencing of EcM root tips from forests in Estonia and Denmark. The taxa on EcM root tips were identified using phylogenetic analyses of large-subunit rDNA sequences derived from sporocarps of 301 pezizalean species, and comparisons with internal transcribed spacer rDNA sequences. Thirty-three species are suggested as EcM symbionts, representing all three major clades of Pezizales, the genera Genea, Geopora, Humaria, Tarzetta, Trichophaea, Wilcoxina, Helvella, Hydnotrya, Tuber, Pachyphloeus, Peziza and Sarcosphaera, and two Pezizaceae anamorphs. EcM of Pezizales species are easily distinguished by their anatomy, particularly thick cell walls and stout hyphae. This study demonstrates that Pezizales species constitute a considerable proportion of the mycobionts in EcM fungal communities in mature boreal deciduous and coniferous forests, in several soil types. Fruit-body sequences and EcM descriptions will facilitate identification of pezizalean EcM in future studies.
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Affiliation(s)
- Leho Tedersoo
- Institute of Botany and Ecology, University of Tartu, 40 Lai Str., 51005 Tartu, Estonia.
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128
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Izzo A, Canright M, Bruns TD. The effects of heat treatments on ectomycorrhizal resistant propagules and their ability to colonize bioassay seedlings. ACTA ACUST UNITED AC 2005; 110:196-202. [PMID: 16387485 DOI: 10.1016/j.mycres.2005.08.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 08/19/2005] [Accepted: 08/30/2005] [Indexed: 11/17/2022]
Abstract
The effect of disturbance on the resistant propagule community (RPC) of ectomycorrhizal fungi has been given relatively little attention. In this study we investigate the effects of heat, one important factor of fire disturbances, on the ability of ectomycorrhizal RPC fungi to colonize Pinus jeffreyi seedlings in greenhouse bioassays. Prior to planting the seed, soils were collected from an old growth mixed-conifer forest in the southern Sierra Nevada, California, USA and then subjected to four heat treatments of none, 45 degrees C, 60 degrees C, and 75 degrees C. After eight months, seedlings were harvested and the ectomycorrhizal fungi colonizing the roots were characterized by molecular methods (PCR-RFLP and DNA sequencing). Rhizopogon species increased in dominance on seedlings grown in soils receiving the 75 degrees C heat treatment. One species significantly increased in frequency, Rhizopogon olivaceotinctus, and two species (Cenococcum geophilum and Wilcoxina sp.) significantly decreased in frequency in the 75 degrees C treatment. The increase of R. olivaceotinctus, coupled with other features of its behavior, suggests that substantial heat disturbances may benefit this species in competing for roots.
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MESH Headings
- Basidiomycota/genetics
- Basidiomycota/growth & development
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Intergenic/chemistry
- DNA, Intergenic/genetics
- Fires
- Hot Temperature
- Pinus/growth & development
- Pinus/microbiology
- Plant Roots/growth & development
- Plant Roots/microbiology
- Polymerase Chain Reaction
- Polymorphism, Restriction Fragment Length
- RNA, Ribosomal, 5.8S/chemistry
- RNA, Ribosomal, 5.8S/genetics
- Seedlings/growth & development
- Seedlings/microbiology
- Sequence Analysis, DNA
- Soil Microbiology
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Affiliation(s)
- Antonio Izzo
- University of California at Berkeley, Department of Plant and Microbial Biology, 321 Koshland Hall, Berkeley, CA 94720-3102, USA.
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129
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Affiliation(s)
- Kathleen K Treseder
- Department of Ecology and Evolutionary Biology, University of California, Irvine, 92697, USA.
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