Publications
Found 65 publication(s)
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Haug, I.; Setaro, S. & Suárez, J.P. (2021): Global AM fungi are dominating mycorrhizal communities in a tropical premontane dry forest in Laipuna, South Ecuador. Mycological Progress 20(6), 837-845.
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DOI: 10.1007/s11557-021-01699-4
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Abstract:
Abstract:
Tropical dry forests are an intricate ecosystem with special adaptations to periods of drought. Arbuscular mycorrhizal fungi (AMF) are essential for plant survival in all terrestrial ecosystems but might be of even greater importance in dry forests as plant growth is limited due to nutrient and water deficiency during the dry season. Tropical dry forests in Ecuador are highly endangered, but studies about AMF communities are scarce. We investigated the AMF community of a premontane semi-deciduous dry forest in South Ecuador during the dry season. We estimated AMF diversity, distribution, and composition of the study site based on operational taxonomic units (OTUs) and compared the results to those from the tropical montane rainforest and páramo in South Ecuador. OTU delimitation was based on part of the small ribosomal subunit obtained by cloning and Sanger sequencing. Nearly all OTUs were Glomeraceae. The four frequent OTUs were Glomus, and comparison with the MaarjAM database revealed these to be globally distributed with a wide range of ecological adaptations. Several OTUs are shared with virtual taxa from dry forests in Africa. Ordination analysis of AMF communities from the tropical dry and montane rainforests in South Ecuador revealed a unique AMF community in the dry forest with only few overlapping OTUs. Most OTUs that were found in both dry and rainforests and on the two continents were globally distributed Glomus.
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Keywords: |
ecuador |
AMF community |
Tropical dry forest |
Sanger sequencing |
Urgiles , N.; Struß, A.; Loján Amijos, P. & Schüßler, A. (2014): Cultured arbuscular mycorrhizal fungi and native soil inocula improve seedling development of two pioneer trees in the Andean region. New Forests 45, 859–874.
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DOI: 10.1007/s11056-014-9442-8
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Abstract:
Abstract:
The tree species Alnus acuminata and Morella pubescens, native to South America, are candidates for soil quality improvement and afforestation of degraded areas and may serve as nurse trees for later inter-planting of other trees, including native crop trees. Both species not only form symbioses with arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF), but also with N2-fixing actinobacteria. Because tree seedlings inoculated with appropriate mycorrhizal fungi in the nursery resist transplanting stress better than non-mycorrhizal seedlings, we evaluated for A. acuminata and M. pubescens the potential of inoculation with mycorrhizal fungi for obtaining robust tree seedlings. For the first time, a laboratory-produced mixed AMF inoculum was tested in comparison with native soil from stands of both tree species, which contains AMF and EMF. Seedlings of both tree species reacted positively to both types of inocula and showed an increase in height, root collar diameter and above- and belowground biomass production, although mycorrhizal root colonization was rather low in M. pubescens. After 6 months, biomass was significantly higher for all mycorrhizal treatments when compared to control treatments, whereas aboveground biomass was approximately doubled for most treatments. To test whether mycorrhiza formation positively influences plant performance under reduced water supply the experiment was conducted under two irrigation regimes. There was no strong response to different levels of watering. Overall, application of native soil inoculum improved growth most. It contained sufficient AMF propagules but potentially also other soil microorganisms that synergistically enhance plant growth performance. However, the AMF inoculum pot-produced under controlled conditions was an efficient alternative for better management of A. acuminata and M. pubescens in the nursery, which in the future may be combined with defined EMF and Frankia inocula for improved management practices.
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Keywords: |
Ecuador |
reforestation |
AM fungi |
Arbuscular mycorrhizal fungi |
Native soil inoculum |
Pioneer trees |
Seedling growth promotion |
Schüßler, A.; Krüger, C. & Urgiles , N. (2016): Phylogenetically diverse AM fungi from Ecuador strongly improve seedling growth of native potential crop trees. Mycorrhiza 26(3), 199--207.
Haug, I.; Setaro, S. & Suarez, J.P. (2019): Species composition of arbuscular mycorrhizal communities changes with elevation in the Andes of South Ecuador. PLOS ONE 14(8), 1-19.
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DOI: 10.1371/journal.pone.0221091
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Abstract:
Abstract:
Arbuscular mycorrhizal fungi (AMF) are the most prominent mycobionts of plants in the tropics, yet little is known about their diversity, species compositions and factors driving AMF distribution patterns. To investigate whether elevation and associated vegetation type affect species composition, we sampled 646 mycorrhizal samples in locations between 1000 and 4000 m above sea level (masl) in the South of Ecuador. We estimated diversity, distribution and species compositions of AMF by cloning and Sanger sequencing the 18S rDNA (the section between AML1 and AML2) and subsequent derivation of fungal OTUs based on 99% sequence similarity. In addition, we analyzed the phylogenetic structure of the sites by computing the mean pairwise distance (MPD) and the mean nearest taxon difference (MNTD) for each elevation level. It revealed that AMF species compositions at 1000 and 2000 masl differ from 3000 and 4000 masl. Lower elevations (1000 and 2000 masl) were dominated by members of Glomeraceae, whereas Acaulosporaceae were more abundant in higher elevations (3000 and 4000 masl). Ordination of OTUs with respect to study sites revealed a correlation to elevation with a continuous turnover of species from lower to higher elevations. Most of the abundant OTUs are not endemic to South Ecuador. We also found a high proportion of rare OTUs at all elevations: 79–85% of OTUs occurred in less than 5% of the samples. Phylogenetic community analysis indicated clustering and evenness for most elevation levels indicating that both, stochastic processes and habitat filtering are driving factors of AMF community compositions.
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Keywords: |
species |
arbuscular mycorrhiza |
Andes |
Arbuscular mycorrhizal fungi |
Urgiles , N.; Haug, I.; Setaro, S. & Aguirre, N. 2016: Introduction to Mycorrhizas in the Tropics with Emphasis on the Montane Forest in Southern Ecuador.: Estudios de Bioversidad 4 (EDILOJA Cía. Ltda., Loja).
Herrera, P.; Suarez, J.P. & Kottke, I. (2010): Orchids keep the ascomycetes outside: a highly diverse group of ascomycetes colonizing the velamen of epiphytic orchids from a tropical mountain rainforest in Southern Ecuador. Mycology 1(4), 262-268.
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DOI: 10.1080/21501203.2010.526645
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Abstract:
Abstract:
Orchid mycorrhizal detection, based only on fungal isolation from roots, is biased due to difficulties in isolating the respec- tive fungi. Previous investigations have shown that mostly ascomycetes, housed in the sheltered compartment of the vela- men covering the roots of epiphytic orchids, are isolated on agar plates. Roots of 83 individual epiphytic orchid of Stelis hallii, S. superbiens, S. concinna, Stelis sp. and Pleurothallis lilijae were sampled in the Reserva Biológica San Francisco, Southern Ecuador. The velamen was partly removed and root tissue macerated and transferred to Petri dishes containing corn meal agar, malt extract agar and Melin Norkrans modified medium. DNA was extracted from the cultures and the 5.8S-ITS region and partial nrLSU sequenced. Phylogenetic analysis revealed members of 12 orders of ascomycetes associ- ated with the roots of these orchids, a much higher diversity than previously known. Twelve isolates were related to the Helotiales. Our results have uncovered some of the fungal diversity within the velamen of epiphytic orchids; fungi invading, most likely, from tree bark or humus accumulation close to the roots.
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Keywords: |
neotropical mountain rain forest |
ascomycota |
epiphytic orchids |
velamen |
Helotiales |
Cruz, D.; Suarez, J.P.; Kottke, I. & Piepenbring, M. (2014): Cryptic species revealed by molecular phylogenetic analysis of sequences obtained from basidiomata of Tulasnella. . Mycologia 106(4), 708-722.
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DOI: 10.3852/12-386
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Abstract:
Abstract:
Delimitation of species and the search for a proper threshold for defining phylogenetic species in fungi are under discussion. In this study, morpho- logical and molecular data are correlated to delimit species of Tulasnella, the most important mycobionts of Orchidaceae, which suffer from poor taxonomy. Resupinate basidiomata of Tulasnella species were collected in Ecuador and Germany, and 11 specimens (seven from Ecuador, four from Germany) were assigned to traditional species concepts by use of morphological keys. The specimens were compared by micro-anatomical examination with 75 specimens of Tulasnella borrowed from fungaria to obtain better insights on variation of characters. Sequences of the ITS region (127) were obtained after cloning from the fresh basidiomata and from pure cultures. Proportional variability of ITS sequences was analyzed within and among the cultures and the specimens designated to different morphospecies. Results sug- gested an intragenomic variation of less than 2%, an intraspecific variation of up to 4% and an interspe- cific divergence of more than 9% in Tulasnella. Cryptic species in Tulasnella, mostly from Ecuador, were revealed by phylogenetic analyses with 4% intraspecific divergence as a minimum threshold for delimiting species. Conventional diagnostic morpho- logical characters appeared insufficient for species characterization. Arguments are presented for molec- ular delimitation of the established species Tulasnella
albida, T. asymmetrica, T. eichleriana, T. cf. pinicola, T. tomaculum and T. violea.
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Keywords: |
interspecific divergence |
intragenomic variability |
intraspecific variability |
morphospecies |
Kottke, I.; Setaro, S.; Haug, I.; Herrera, P.; Cruz, D.; Suarez, J.P.; Fries, A.; Adams, J.; Gerique, A.; Homeier, J. & Werner, F.A. (2013): Mycorrhiza Networks Promote Biodiversity and Stabilize the Tropical Mountain Rain Forest Ecosystem: Perspectives for Understanding Complex Communities. In: J. Bendix, E. Beck, A. Bräuning, F. Makeschin, R. Mosandl, S. Scheu, W. Wilcke. (eds.): Ecosystem Services, Biodiversity and Environmental Change in a Tropical Mountain Ecosystem of Sou l ( 221), Springer Verlag, Heidelberg, 438.
Kottke, I.; Kovács, G. & Eötvös Lorand University (2013): Mycorhrizae - Rhizosphere determinants of plant communities: What can we learn from the tropics?. In: Amram Eshel und Tom Beeckman (eds.): Plant Roots - The Hidden Half (Vierte Auflage ), CRC Press, Buch.
Haug, I.; Setaro, S. & Suarez, J.P. (2013): Reforestation sites show similar and nested AMF communities to an adjacent pristine forest in a tropical mountain area of South Ecuador . PLOS ONE 8, e63524.
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DOI: 10.1371/journal.pone.0063524
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Abstract:
Abstract:
Arbuscular mycorrhizae are important for growth and survival of tropical trees. We studied the community of arbuscular mycorrhizal fungi in a tropical mountain rain forest and in neighbouring reforestation plots in the area of Reserva Biológica San Francisco (South Ecuador). The arbuscular mycorrhizal fungi were analysed with molecular methods sequencing part of the 18S rDNA. The sequences were classified as Operational Taxonomic Units (OTUs). We found high fungal species richness with OTUs belonging to Glomerales, Diversisporales and Archaeosporales. Despite intensive sampling, the rarefaction curves are still unsaturated for the pristine forest and the reforestation plots. The communities consisted of few frequent and many rare species. No specific interactions are recognizable. The plant individuals are associated with one to ten arbuscular mycorrhizal fungi and mostly with one to four. The fungal compositions associated with single plant individuals show a great variability and variety within one plant species. Planted and naturally occurring plants show high similarities in their fungal communities. Pristine forest and reforestation plots showed similar richness, similar diversity and a significantly nested structure of plant-AMF community. The results indicate that small-scale fragmentation presently found in this area has not destroyed the natural AMF community, at least yet. Thus, the regeneration potential of natural forest vegetation at the tested sites is not inhibited by a lack of appropriate mycobionts.
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Keywords: |
forest |
reforestation |
AM fungi |
Setaro, S.; Garnica, S.; Herrera, P. & Goeker, M. (2011): A clustering optimization strategy to estimate species richness of Sebacinales in the tropical Andes based on molecular sequences from distinct DNA regions. Biodiversity and Conservation 21, 2269-2285.
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DOI: 10.1007/s10531-011-0205-y
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Abstract:
Abstract:
Fungi are believed to be diverse in the tropics, but because many groups are
only known from their DNA sequences this hampers comparative diversity studies. We
investigated mycorrhizal Sebacinales (Basidiomycota) of 67 individuals of Ericaceae and
Orchidaceae in a tropical mountain ecosystem in Southern Ecuador to provide a ?rst
estimate of whether these fungi are particularly diverse in the Northern Andes. We par-
tially sequenced the internal transcribed spacer (ITS) and large subunit (LSU) regions of
the nuclear ribosomal DNA and analyzed them together with all Sebacinales sequences
available from GenBank. The clustering optimization technique was used to determine
clustering parameters that maximize the comparability between molecular operational
taxonomic units (MOTUs) obtained from the distinct loci. Sampling effort and species
richness were estimated with rarefaction-accumulation curves and non-parametric esti-
mation using Chao2 and compared between Southern Ecuador and France. Clustering
optimization indicated that a 1% LSU distance threshold corresponds to the commonly
used 3% dissimilarity threshold for ITS, and that a clustering algorithm close to single-
linkage clustering is optimal. The resulting clusters show that about 8?9% of observed Sebacinales MOTUs occur in the study area and that most of these MOTUs are endemic
(74%). The widespread MOTUs from Southern Ecuador were also found in Panama, North
America and Europe. The estimation of species richness revealed unsaturated sampling of
Sebacinales in general and also in our study area. Our results suggest a high diversity of
Sebacinales associated with Ericaceae and Orchidaceae at the study site in Southern
Ecuador, but no hotspot of Sebacinales in comparison with other areas.
Setaro, S. & Kron, K. (2011): Neotropical and North American Vaccinioideae (Ericaceae) share their mycorrhizal Sebacinales - an indication for concerted migration?. PLoS Currents: Tree of Life NA, NA.
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DOI: 10.1371/currents.RRN1227
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Abstract:
Abstract:
Neotropical Vaccinioideae (Ericaceae) are evolutionary rather young and presumably of Northern Hemisphere origin. Vaccinioideae are highly dependent on their mycorrhizal symbionts and Sebacinales (basidiomycetes) were previously found to be the dominant mycobionts of Andean Clade Vaccinioideae (Neotropical Vaccinieae). We were interested to see whether the North American Vaccinioideae reached the Neotropics with their mycobionts or whether they acquired new, local Sebacinales.
We investigated Sebacinales of 58 individuals of Vaccinioideae from Ecuador, Panama and North America to examine whether mycobionts of each region are distantly or closely related.
We isolated the ITS of the ribosomal nuclear DNA in order to infer a molecular phylogeny of Sebacinales and to determine Molecular Operational Taxonomic Units (MOTUs). MOTU delimitation was based on a 3% threshold of ITS variability and conducted with complete linkage clustering. The analyses revealed that most Sebacinales from Ecuador, Panama and North America are closely related and that two MOTUs out of 33 have a distribution ranging from the Neotropics to the Pacific Northwest of North America. The data suggest that Neotropical and temperate Vaccinioideae of North America share their Sebacinales communities and that plants and fungi migrated together.
Cruz, D.; Suarez, J.P.; Kottke, I.; Piepenbring, M. & Oberwinkler, F. (2011): Defining species in Tulasnella by correlating morphology and nrDNA ITS-5.8S sequence data of basidiomata from a tropical Andean forest . Mycological Progress 10, 229-238.
Haug, I.; Preussig, M.; Setaro, S.; Suarez, J.P.; Oberwinkler, F. & Kottke, I. (2008): Mycorrhizal fungi checklist. In: S. Liede-Schumann; S.-W. Breckle (eds.): Provisional checklist of flora and fauna of the San Francisco Valley and surroundings (1 st 4), Society of Tropical Ecology, Bonn, 119-123.
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Mycorrhizas of vascular plants and mycorrhiza-like associations of liverworts are integral parts of terrestrial ecosystems, but have rarely been studied in tropical mountain rain forests. Our lightand electron microscopical studies at the RBSF revealed that the roots of nearly all tree species were well colonized by structurally diverse arbuscular mycorrhizal Glomeromycota (Haug et al. 2004, Beck et al. 2005), a few tree species by ectomycorrhizal Ascoand Basidiomycota (Haug et al. 2005), and that epiphytic, pleurothallid orchids formed mycorrhizas with Tulasnella species and members of the Sebacinales (Basidiomycota) (Suárez et al. 2006, Kottke et al. 2007). Species of Sebacinales also occurred in mycorrhizas of hemiepiphytic ericads (Setaro et al. 2006) and Tulasnella species were found in liverworts belonging to the Aneuraceae (Kottke et al. 2007). Traditionally, studies on biodiversity and host specificity have been based on morphologically defined species. No such approach was feasible in the case of the mycobionts in our study as the fungi did not display sufficient structural differences in the mycorrhizas for delimitation of morphospecies. The identification of the mycorrhiza-forming fungi in the forest could be done neither by spore nor by fruiting-body sampling, as both methods would have yielded only a very narrow spectrum of the fungal communities (Husband et al. 2002, Sanders 2004a). Instead, direct sequencing of the associated fungi from the plant material was carried out (Kottke et al. 2007). Given our present stage of knowledge, the sequence types (ribosomal genotypes) can rarely be precisely related to either morphological or biological species. However, the amount of information derived from the sequences of the ribosomal genes appeared to be meaningful in previous ecological studies on arbuscular mycorrhizas (Helgason et al. 2002, Husband et al. 2002, Sanders 2004b) as well as on mycorrhiza-forming Basidiomycota (Bidartondo et al. 2003, Bidartondo et al. 2004). However, analysis of biodiversity and specificity of the mycobionts from field samples using DNA sequences also poses problems. Firstly, results are limited by the available primers. Secondly, problems resulted from the observation that the ribosomal genes can show intraspecific variation, especially in the case of the multinucleate Glomeromycota (Sanders et al. 1995, Lloyd-Macgilp et al. 1996, Clapp et al. 2001, Sanders 2004b). These facts pose general, unresolved challenges to a species concept based on meaningful levels of genetic diversity. Thus the list of fungal sequences presented here is far from being complete and far from being a species list.
Haug, I.; Wubet, T.; Weiß, M.; Aguirre, N.; Weber, M.; Günter, S. & Kottke, I. (2010): Species-rich but distinct arbuscular mycorrhizal communities in reforestation plots on degraded pastures and in neighboring pristine tropical mountain rain forest. Tropical Ecology 51, 125-148.
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Abstract: For the first time in tropical mountain rain forest, arbuscular mycorrhizal fungal
richness and community composition was investigated from planted seedlings of Cedrela
montana, Heliocarpus americanus, Juglans neotropica and Tabebuia chrysantha in reforestation
plots on degraded pastures. A segment of fungal 18S rDNA was sequenced from the mycorrhizas.
Sequences were compared with those obtained from mycorrhizas of adult trees of 30
species in the neighboring, pristine tropical mountain rain forest. In total, 193 glomeromycotan
sequences were analyzed, 130 of them previously unpublished. Members of Glomeraceae,
Acaulosporaceae, Gigasporaceae and Archaeosporales were found in both habitats, with Glomus
Group A sequences being by far the most diverse and abundant. Glomus Group A sequence type
richness did not appear to differ between the habitats; a large number was observed in both.
Glomus Group A sequence type composition, however, was found distinctly different. Seedlings
were rarely colonized by fungi of the pristine forest but trapped a number of fungi known from
other areas, which were rarely found in the pristine forest.
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Keywords: |
Cedrela montana |
Heliocarpus americanus |
Tabebuia chrysantha |
reforestation |
Setaria sphacelata |
degraded pastures |
glomeromycota |
juglans neotropica |
neotropical mountain rain forest |
ribosomal 18S RNA gene |
Kottke, I.; Suarez, J.P.; Cruz, D.; Herrera, P.; Bauer, R.; Haug, I. & Garnica, S. (2010): Atractiellomycetes belonging to the 'rust' lineage (Pucciniomycotina) form mycorrhizae with terrestrial and epiphytic neotropical orchids.. Proceedings Royal Society B 277, 1289-1296.
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DOI: 10.1098/repb.2009.1884
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Abstract:
Abstract:
Distinctive groups of fungi are involved in the diverse mycorrhizal associations of land plants. All previously known mycorrhiza forming Basidiomycota associated with trees, ericads, liverworts or orchids are hosted in Agaricomycetes, Agaricomycotina. Here we demonstrate for the first time that Atractiellomycetes, members of the ?rust? lineage (Pucciniomycotina), are mycobionts of orchids. The mycobionts of 103 terrestrial and epiphytic orchid individuals, sampled in the tropical mountain rain forest of Southern Ecuador, were identified by sequencing the whole ITS1-5.8S-ITS2 region and part of 28S rDNA. Mycorrhizae of 13 orchid individuals were investigated by transmission electron microscopy. Simple septal pores and symplechosomes in the hyphal coils of mycorrhizae from four orchid individuals indicated members of Atractiellomycetes. Molecular phylogeny of sequences from mycobionts of 32 orchid individuals out of 103 samples confirmed Atractiellomycetes and the placement in Pucciniomycotina, previously known to comprise only parasitic and saprophytic fungi. Thus, our finding reveals these fungi, frequently associated to neotropical orchids, as the most basal living basidiomycetes involved in mycorrhizal associations of land plants.
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Keywords: |
Atractiellales |
orchid mycorrhiza |
pucciniomycotina |
helicogloea |
neotropical mountain rain forest |
simple-septate basidiomycota |
Urgiles , N.; Loján Amijos, P.; Aguirre, N.; Blaschke, H.; Günter, S.; Stimm, B. & Kottke, I. (2009): Application of mycorrhizal roots improves growth of tropical tree seedlings in the nursery: a step towards reforestation with native species in the Andes of Ecuador. New Forests 38(3), 229-239.
Brehm, G.; Homeier, J.; Fiedler, K.; Kottke, I.; Illig, J.; Noeske, N.M.; Werner, F.A. & Breckle, S.W. (2008): Mountain rain forests in southern Ecuador as a hotspot of biodiversity - limited knowledge and diverging patterns. In: Beck, Erwin; Bendix, Jörg; Kottke, Ingrid; Makeschin, Franz; Mosandl, Reinhard (eds.): Gradients in a Tropical Mountain Ecosystem of Ecuador (Ecological Studies 198), Springer, Berlin Heidelberg, 15-24.
Beck, E.; Kottke, I.; Bendix, J.; Makeschin, F. & Mosandl, R. (2008): Gradients in a Tropical Mountain Ecosystem - a Synthesis. In: Beck, Erwin; Bendix, Jörg; Kottke, Ingrid; Makeschin, Franz; Mosandl, Reinhard (eds.): Gradients in a Tropical Mountain Ecosystem of Ecuador (Ecological Studies 198), Springer, Berlin Heidelberg, 467-480.
Suarez, J.P.; Weiß, M.; Oberwinkler, F. & Kottke, I. (2009): Epiphytic orchids in a mountain rain forest in southern Ecuador harbor groups of mycorrhiza-forming Tulasnellales and Sebacinales sibgroup B (Basidiomycota). In: Alec M. Pridgeon; Juan Pablo Suárez (eds.): Proceedings of the Second Scientific Conference on Andean Orchids (First edition ), Universidad Técnica Particular de Loja, Loja, Ecuador, 248.
Kottke, I. & Suarez, J.P. (2009): Mutualistic root inhabiting fungi of orchids - identificatin and functional types. In: Alec M. Pridgeon; Juan Pablo Suarez (eds.): Proceedings of the Second Scientific Conference on Andean Orchids (First edition ), Universidad Técnica Particular de Loja, Loja, Ecuador, 248.
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Abstract:
Orchids depend on fungi for germination and protocorm development, but also form mycorrhizas during life time. Mycorrhizal fungi are, therefore, discussed as driving force in orchid evolution and speciation. However, for serious discussion reliable data on fungal identity are crucial. Application of molecular phylogeny and transmission electron microscopy congruently revealed distinct fungal groups as orchid mycobionts. Sebacinales Group B, Tulasnellales, and Ceratobasidiales were found associated with terrestrial orchids in open grasslands and arbuscular mycorrhizal forests and with epiphytes, while Sebacinales Group A, Thelephorales, Russulales, some Euagaricales and Tuberales form mycorrhizas with terrestrial orchids in ectomycorrhizal forests. Enzyme and isotope analyses revealed that the former obtain carbon from rotten organic material to nourish the protocorm while the latter take carbon from ectomycorrhizas of woody plants to feed protocorms and adult heterotrophic or mixotrophic plants. Mycobionts of terrestrial orchids appeared to be of narrower host range than previously expected, and co-speciation was discussed. The few investigations on mycobionts of epiphytic orchids so far indicated sharing of hosts. Further information is needed of mycobionts from tropical terrestrial and epiphytic orchids at well resolved molecular level of fungal identity, in situ prove, host range, and ecology to finally evaluate if association strategies differ between epiphytic and terrestrial orchids or between temperate and tropical habitats.
Beck, E.; Mosandl, R.; Richter, M. & Kottke, I. (2008): The Investigated Gradients. In: Beck, Erwin; Bendix, Jörg; Kottke, Ingrid; Makeschin, Franz; Mosandl, Reinhard (eds.): Gradients in a Tropical Mountain Ecosystem of Ecuador (Ecological Studies 198), Springer, Berlin Heidelberg, 55-62.
Suarez, J.P.; Weiß, M.; Abele, A.; Oberwinkler, F. & Kottke, I. (2008): Members of Sebacinales subgroup B form mycorrhizae with epiphytic orchids in a neotropical mountain rain forest. Mycological Progress 7, 75-85.
Suarez, J.P.; Weiß, M.; Abele, A.; Garnica, S.; Oberwinkler, F. & Kottke, I. (2006): Diverse tulasnelloid fungi form mycorrhizas with epiphytic orchids in an Andean cloud forest.. Mycological Research 110, 1257-1270.
Kottke, I.; Beck, A.; Haug, I.; Setaro, S. & Suarez, J.P. (2008): Mycorrhizal fungi and plant diversity in tropical mountain rainforest. In: S. Robbert Gradstein; Jürgen Homeier; Dirk Gansert (eds.): The Tropical Mountain Forest (Biodiversity and Ecology Series 2), Universitätsverlag Göttingen, 67-78.
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Mycorrhizal fungi, because of their obligate symbiotic interaction with plant roots, may either promote or restrict plant diversity depending on broad or narrow plant-fungus relationships. It was challenging to investigate these relationships in a hotspot of plant diversity, the tropical mountain rain forest of Southern Ecuador. Inventories, based on morphotyping and DNA sequencing, were carried out on the mycorrhizal fungi associated with 115 tree species belonging to 40 families, 20 ericad species and 4 epiphytic orchid species in an area of about 12 ha in the Reserva Biológica San Francisco at 1 850 to 2 300 m. Results indicated that diverse Glomeromycota with broad host range may promote high tree diversity, while diverse but plant-family restricted Sebacinales likely support closely related Andean ericads, and diverse, orchidrestricted Tulasnellales and Sebacinales closely related epiphytic orchids. Ectomycorrhizal fungi were found specifically associated with three Nyctaginacean trees and with one member of Melastomataceae. We conclude that the extraordinary high plant diversity of the tropical Andean forest is predominantly promoted by a broad range of mycorrhizal fungi but selected trees are supported by specific fungi.
Kottke, I.; Beck, A.; Haug, I.; Setaro, S.; Jeske, V.; Suarez, J.P.; Paxmiño, L.; Preussig, M.; Nebel, M. & Oberwinkler, F. (2008): Mycorrhizal state and new and special features of mycorrhizae of trees, ericads, orchids, ferns and liverworts in the tropical mountain rain forest of South Ecuador. In: Beck, Erwin; Bendix, Jörg; Kottke, Ingrid; Makeschin, Franz; Mosandl, Reinhard (eds.): Gradients in a Tropical Mountain Ecosystem of Ecuador (Ecological Studies 198), Springer, Berlin Heidelberg, 137-147.
Beck, E. & Kottke, I. (2008): Facing a hotspot of tropical biodiversity. Basic and Applied Ecology 9, 1-3.
Setaro, S.; Kottke, I. & Oberwinkler, F. (2006): Anatomy and ultrastructure of mycorrhizal associations of neotropical Ericaceae. Mycological Progress 5, 243-254.
Kottke, I.; Haug, I.; Setaro, S.; Suarez, J.P.; Weiß, M.; Preussig, M.; Nebel, M. & Oberwinkler, F. (2008): Guilds of mycorrhizal fungi and their relation to trees, ericads, orchids and liverworts in a neotropical mountain rain forest . Basic and Applied Ecology 9, 13-23.
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DOI: 10.1016/j.baae.2007.03.007
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Abstract:
Abstract:
Mycorrhizas of vascular plants and mycorrhiza-like associations of liverworts and hornworts are integral parts of terrestrial ecosystems, but have rarely been studied in tropical mountain rain forests. The tropical mountain rain forest area of the Reserva Biológica San Francisco in South Ecuador situated on the eastern slope of the Cordillera El Consuelo is exceptionally rich in tree species, ericads and orchids, but also in liverworts. Previous light and electron microscopical studies revealed that tree roots are well colonized by structurally diverse Glomeromycota, and that epiphytic, pleurothallid orchids form mycorrhizas with members of the Tulasnellales and the Sebacinales (Basidiomycota). Sebacinales also occurred in mycorrhizas of hemiepiphytic ericads and Tulasnellas were found in liverworts belonging to the Aneuraceae. On the basis of these findings we hypothesized that symbiotic fungi with a broad host range created shared guilds or even fungal networks between different plant species and plant families. To test this hypothesis, molecular phylogenetic studies of the fungi associated with roots and thalli were carried out using sequences of the nuclear rDNA coding for the small subunit rRNA (nucSSU) of Glomeromycota and the large subunit rRNA (nucLSU) of Basidiomycota. Sequence analyses showed that Sebacinales and Tulasnellas were only shared within but not between ericads and orchids or between liverworts and orchids, respectively. Regarding arbuscular mycorrhiza forming trees, however, 18 out of 33 Glomus sequence types were shared by two to four tree species belonging to distinct families. Nearly all investigated trees shared one sequence type with another tree individual. Host range and potential shared guilds appeared to be restricted to the plant family level for Basidiomycota, but were covering diverse plant families in case of Glomeromycota. Given that the sequence types as defined here correspond to fungal species, our findings indicate potential fungal networks between trees.
Beck, A.; Haug, I.; Oberwinkler, F. & Kottke, I. (2007): Structural characterisation and molecular identification of arbuscular mycorrhiza morphotypes of Alzatea verticillata (Alzateaceae) a prominent tree in the tropical mountain rain forest of South Ecuad. Mycorrhiza 17, 607-625.
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DOI: 10.1007/s00572-007-0139-0
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Abstract:
Abstract:
The vast majority of the highly diverse trees in the tropical mountain rain forest of South Ecuador form arbuscular mycorrhizas and previous molecular investigations revealed a high diversity of fungi. Here we present a first trial to link fungal DNA-sequences with defined morphotypes characterized on the basis of partly new mycelial features obtained from field material of one tree species, Alzatea verticillata. Fine roots were halved lengthwise to study the mycelium anatomy on one half and to obtain fungal nuclear rDNA coding for the small subunit rRNA (nucSSU) of Glomeromycota from the other half. Light microscopy revealed conspicuously large amounts of mycelium attaching to the surface of the rootlets. The mycelium formed fine or large branched appressoria-like plates, vesicles of regular or irregular shape, and very fine, multi-branched hyphal systems ensheathed by septate hyphae. These previously undescribed features of the supraradical mycelia combined with intraradical mycelium structures were used for distinguishing of four main morphogroups and subordinate 14 morphotypes. DNA sequences of Glomus-group A, Acaulospora and Gigaspora were obtained and linked to three morphogroups. Two sequence types within Glomus-group A could be tentatively associated to subordinate morphotypes.