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Eric Chauvet - One of the best experts on this subject based on the ideXlab platform.
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aquatic Hyphomycetes and litter decomposition in tropical subtropical low order streams
Fungal Ecology, 2016Co-Authors: Manuel A S Graca, Kevin D Hyde, Eric ChauvetAbstract:Leaf litter decomposition is an important ecosystem function carried out by a diverse array of consumers, including aquatic Hyphomycetes. Aquatic Hyphomycetes are found in streams worldwide, but their diversity and abundance varies across systems. In general, species diversity is lower across tropical and subtropical systems when compared with temperate biomes. The low diversity in tropical and subtropical areas may be related to: (a) lower seasonality; (b) our inability to detect fungi by traditional techniques; (c) low turbulence of rivers where many studies were carried out; (d) low nutrient content in many studied tropical systems; (e) leaves highly defended against consumers; and (1) competition from other decomposers. In terms of function, fungal biomass, sporulation rates and litter decomposition by aquatic Hyphomycetes in the tropics was reported to be equivalent to or much lower than observed in temperate zones. The feeding ecology of shredder invertebrates is strongly related to the presence of microbial decomposers in the environment. The lack of shredders reported for some tropical rivers may be related to a low microbial biomass, well defended tropical leaves and frequent hydrological events which remove leaves before they can be used by shredders. Seasonal variations in rain fall in tropical and subtropical systems are likely to affect litter fall, the identity and quality of litter, the reproduction of aquatic Hyphomycetes (due to turbulence effects) and therefore the community composition of aquatic Hyphomycetes throughout the year. Future research on aquatic Hyphomycetes and litter decomposition in the tropics and sub-tropics should address the diversity/identity gap, altitudinal gradient changes and the contribution of aquatic Hyphomycetes to the trophic ecology of shredders. (C) 2015 Elsevier Ltd and The British Mycological Society. All rights reserved.
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Leaf-associated fungal diversity in acidified streams: insights from combining traditional and molecular approaches
Environmental Microbiology, 2014Co-Authors: Hugues Clivot, Julien Cornut, Eric Chauvet, Arnaud Elger, Pascal Poupin, Francois Guerold, Christophe PagnoutAbstract:We combined microscopic and molecular methods to investigate fungal assemblages on alder leaf litter exposed in the benthic and hyporheic zones of five streams across a gradient of increasing acidification for 4 weeks. The results showed that acidification and elevated Al concentrations strongly depressed sporulating aquatic Hyphomycetes diversity in both zones of streams, while fungal diversity assessed by denaturing gradient gel electrophoresis (DGGE) appeared unaffected. Clone library analyses revealed that fungal communities on leaves were dominated by members of Ascomycetes and to a lesser extent by Basidiomycetes and Chytridiomycetes. An important contribution of terrestrial fungi was observed in both zones of the most acidified stream and in the hyporheic zone of the reference circumneutral stream. The highest leaf breakdown rate was observed in the circumneutral stream and occurred in the presence of both the highest diversity of sporulating aquatic Hyphomycetes and the highest contribution to clone libraries of sequences affiliated with aquatic Hyphomycetes. Both methods underline the major role played by aquatic Hyphomycetes in leaf decomposition process. Our findings also bring out new highlights on the identity of leaf-associated fungal communities and their responses to anthropogenic alteration of running water ecosystems.
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Diversity patterns of leaf-associated aquatic Hyphomycetes along a broad latitudinal gradient
Fungal Ecology, 2013Co-Authors: Jérémy Jabiol, Andreas Bruder, Mark O. Gessner, Marika Makkonen, Brendan G. Mckie, Edwin T.h.m. Peeters, Veronique C.a. Vos, Eric ChauvetAbstract:Information about the global distribution of aquatic Hyphomycetes is scarce, despite the primary importance of these fungi in stream ecosystem functioning. In particular, the relationship between their diversity and latitude remains unclear, due to a lack of coor- dinated surveys across broad latitudinal ranges. This study is a first report on latitudinal patterns of aquatic hyphomycete diversity associated with native leaf-litter species in five streams located along a gradient extending from the subarctic to the tropics. Exposure of leaf litter in mesh bags of three different mesh sizes facilitated assessing the effects of including or excluding different size-classes of litter-consuming invertebrates. Aquatic hyphomycete evenness was notably constant across all sites, whereas species richness and diversity, expressed as the Hill number, reached a maximum at mid-latitudes (Medi- terranean and temperate streams). These latitudinal patterns were consistent across litter species, despite a notable influence of litter identity on fungal communities at the local scale. As a result, the bell-shaped distribution of species richness and Hill diversity devi- ated markedly from the latitudinal patterns of most other groups of organisms. Differences in the body-size distribution of invertebrate communities colonizing the leaves had no effect on aquatic hyphomycete species richness, Hill diversity or evenness, but inverte- brates could still influence fungal communities by depleting litter, an effect that was not captured by the design of our experiment.
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Synergistic effects of water temperature and dissolved nutrients on litter decomposition and associated fungi
Global Change Biology, 2011Co-Authors: Veronica Ferreira, Eric ChauvetAbstract:In woodland streams, the decomposition of allochthonous organic matter constitutes a fundamental ecosystem process, where aquatic Hyphomycetes play a pivotal role. It is therefore greatly affected by water temperature and nutrient concentrations. The individual effects of these factors on the decomposition of litter have been studied previously. However, in the climate warming scenario predicted for this century, water temperature and nutrient concentrations are expected to increase simultaneously, and their combined effects on litter decomposition and associated biological activity remains unevaluated. In this study, we addressed the individual and combined effects of water temperature (three levels) and nutrient concentrations (two levels) on the decomposition of alder leaves and associated aquatic Hyphomycetes in microcosms. Decomposition rates across treatments varied between 0.0041dayˉ¹ at 5°C and low nutrient level and 0.0100 dayˉ¹ at 15°C and high nutrient level. The stimulation of biological variables at high nutrients and temperatures indicates that nutrient enrichment of streams might have a higher stimulatory effect on fungal performance and decomposition rates under a warming scenario than at present. The stimulation of fungal biomass and sporulation with increasing temperature at both nutrient levels shows that increases in water temperature might enhance fungal growth and reproduction in both oligotrophic and eutrophic streams. The stimulation of fungal respiration and litter decomposition with increasing temperature at high nutrients indicates that stimulation of carbon mineralization will probably occur at eutrophied streams, while oligotrophic conditions seem to be 'protected' from warming. All biological variables were stimulated when both factors increased, as a result of synergistic interactions between factors. Increased water temperature and nutrient level also affected the structure of aquatic hyphomycete assemblages. It is plausible that if water quality of presently eutrophied streams is improved, the potential stimulatory effects of future increases in water temperature on aquatic biota and processes might be mitigated.
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Influence of conidial traits and leaf structure on attachment success of aquatic Hyphomycetes on leaf litter
Mycologia, 2007Co-Authors: Christian K. Dang, Mark O. Gessner, Eric ChauvetAbstract:Attachment of conidia on leaves is a critical first step in the life cycle of aquatic Hyphomycetes in streams. In a first series of microcosm experiments, attachment success of three common aquatic hyphomycete species differing in conidial shape (compact, filiform and tetraradiate) was determined on two leaf species, black alder and downy oak. Fungal species identity and leaf surface structure significantly affected conidial attachment after 24 h. The lower sides of oak leaves with extensive tufts trapped 2.4-8.8 more conidia than the upper sides of oak leaves and both sides of alder leaves. In a second experiment with seven fungal species, attachment success of two species with tetraradiate conidia was much greater than that of two other tetraradiate and three compact conidia, which all had similar attachment success. The species with the largest spores was also the most successful, but this pattern was not consistent across the size range of tested conidia. These results highlight the importance of leaf surface structure, possibly conidial shape and size and additional properties of aquatic hyphomycete conidia in determining attachment success on leaves and they point to the potential role of these factors. in structuring fungal communities on decomposing leaves in streams.
Felix Barlocher - One of the best experts on this subject based on the ideXlab platform.
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quantitative real time pcr as a promising tool for the detection and quantification of leaf associated fungal species a proof of concept using alatospora pulchella
PLOS ONE, 2017Co-Authors: Alexander Feckler, Anne Schrimpf, Mirco Bundschuh, Felix Barlocher, Patrick Baudy, Julien CornutAbstract:Traditional methods to identify aquatic Hyphomycetes rely on the morphology of released conidia, which can lead to misidentifications or underestimates of species richness due to convergent morphological evolution and the presence of non-sporulating mycelia. Molecular methods allow fungal identification irrespective of the presence of conidia or their morphology. As a proof-of-concept, we established a quantitative real-time polymerase chain reaction (qPCR) assay to accurately quantify the amount of DNA as a proxy for the biomass of an aquatic hyphomycete species (Alatospora pulchella). Our study showed discrimination even among genetically closely-related species, with a high sensitivity and a reliable quantification down to 9.9 fg DNA (3 PCR forming units; LoD) and 155.0 fg DNA (47 PCR forming units; LoQ), respectively. The assay's specificity was validated for environmental samples that harboured diverse microbial communities and likely contained PCR-inhibiting substances. This makes qPCR a promising tool to gain deeper insights into the ecological roles of aquatic Hyphomycetes and other microorganisms.
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Beyond the water column: aquatic Hyphomycetes outside their preferred habitat
Fungal Ecology, 2016Co-Authors: Eri Chauvet, Julien Cornut, Kandikere R. Sridhar, Marc-andré Selosse, Felix BarlocherAbstract:Aquatic Hyphomycetes have adapted to running waters by their uncommon conidial shape, which facilitates dispersal as well as adherence to plant substrata. However, they have been early and regularly reported to occur in a variety of environments other than their preferred habitat (e.g., in lentic freshwaters, brackish and marine environments, in terrestrial niches such as stream banks, dew, canopy waters and tree holes). In addition, several aquatic Hyphomycetes have adapted to a mutualistic lifestyle which may involve plant defence, as endophytes in leaves, gymnosperm needles, orchids and terrestrial roots. There are several lines of evidence suggesting that aquatic Hyphomycetes survive under terrestrial conditions due to their sexual states. Although exhibiting higher diversity in pristine streams, aquatic Hyphomycetes can survive environmental stress, e.g., pollution or river intermittency. They also inhabit ground and hyporheic waters, where they appear to be subjected to both physical and physiological selection. Appropriate methods including molecular ones should provide a more comprehensive view of the occurrence and ecological roles of aquatic Hyphomycetes outside their preferred habitat.
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biology and ecological functions of aquatic Hyphomycetes in a warming climate
Fungal Ecology, 2016Co-Authors: Cristina Canhoto, Ana Lucia Goncalves, Felix BarlocherAbstract:Abstract The average global temperature is predicted to increase by 4 °C by the end of this century. Biotas of running waters, especially of low order streams, depend heavily on imports from the riparian vegetation. Autumn-shed leaves are decomposed and conditioned for invertebrate consumption by aquatic Hyphomycetes. Overall metabolism, growth and reproduction of these fungi will be directly affected by rising temperatures and associated changes. Both resource (leaves) and consumers/competitors (leaf-eating invertebrates) will react to the same changes; their responses may indirectly influence fungal activities. Published studies on fungal reactions to climate change often reach contradictory and location-specific conclusions. Most commonly, at least in temperate streams, higher temperatures stimulate fungal metabolism, though there may be shifts in fungal allocations to enzyme activities, growth and reproduction. On a global scale, there is some evidence that rising temperatures will increase the contribution of aquatic Hyphomycetes to litter processing in streams at the expense of invertebrates.
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aquatic Hyphomycetes in a changing environment
Fungal Ecology, 2016Co-Authors: Felix BarlocherAbstract:Abstract In 1942, Ingold documented an ecologically defined group of fungi, aquatic Hyphomycetes, on autumn-shed leaves decaying in streams. They were shown to be vital intermediaries between the nutritionally poor leaf substratum and leaf-eating invertebrates. Research has subsequently emphasized functional aspects such as leaf decomposition and nutritional conditioning by fungi. Structural aspects (community composition) have attracted less attention, partly because of the difficulties of identifying fungal mycelia in situ. Extraction, amplification (PCR, qPCR) and characterization of DNA and RNA, and, more recently, of proteins, allow much greater insights into the presence of fungal taxa, their metabolic status (dead, dormant or active), and their potential and actual participation in decomposition processes. This approach can yield huge amounts of data, and major challenges today are the development and application of suitable bioinformatics techniques. The complexity of data collection and evaluation favour interdisciplinary teams of researchers. Fungi are major players in most ecosystems and are increasingly affected by human impacts. Changing land use, eutrophication/pollution and climate change are among the major factors that affect diversity and ecological functions of aquatic Hyphomycetes.
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biogeography of aquatic Hyphomycetes current knowledge and future perspectives
Fungal Ecology, 2016Co-Authors: Sofia Alexandra Ferreira Duarte, Felix Barlocher, Claudia Pascoal, Fernanda CassioAbstract:Abstract Since Ingold's (1942) initial description, mycologists have been interested in deciphering global distribution patterns of aquatic Hyphomycetes, a group of fungi that play a key role in plant-litter decomposition in freshwaters. However, many questions remain largely unanswered. In this review, we used distribution data of morphospecies from studies throughout the world in an attempt to better understand the magnitude of global species richness, patterns of biodiversity and the extent of cosmopolitanism versus endemism. Sampling efforts have varied among geographic regions, and correlate significantly with species richness. Community similarity decreased with geographic or latitudinal distance. Species richness was highest at mid-latitudes (temperate streams), and high community similarities were found between geographically distant locations in similar climatic zones. Studies relying on morphotypes have undoubtedly provided relevant information on the geographic distribution of aquatic Hyphomycetes. However, metagenomic approaches combining taxonomic, phylogenetic and functional diversity in coordinated surveys will be the best option to better decipher diversity patterns of these fungi and their functional roles at a global scale.
Keller Suberkropp - One of the best experts on this subject based on the ideXlab platform.
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contribution of fungal biomass to the growth of the shredder pycnopsyche gentilis trichoptera limnephilidae
Freshwater Biology, 2009Co-Authors: Namil Chung, Keller SuberkroppAbstract:Summary 1. 1. It has been accepted that aquatic Hyphomycetes colonising submerged leaves increase the nutritional value of leaf detritus and suggested that fungal biomass plays a greater role in the growth of shredders than leaf tissue itself. However, it is not clear what proportion of the nutritional needs of shredders is met by fungal biomass. 2. We fed Pycnopsyche gentilis larvae with tulip poplar (Liriodendron tulipifera) leaf discs colonised by the aquatic hyphomycete, Anguillospora filiformis, which had been radiolabelled to quantify the contribution of fungal carbon to the growth of the shredder at different larval developmental stages. Instantaneous growth rates of larvae on this diet were also estimated. 3. When provided with fungal-colonised leaves (14–16% fungal biomass), the third and the fifth instar larvae of P. gentilis grew at the rates of 0.061 and 0.034 day−1, respectively, but on a diet of sterile leaves, both larval instars lost weight. The incorporation rates of fungal carbon were 31.6 μg C mg−1 AFDM day−1, accounting for 100% of the daily growth rate of the third instar larvae and 8.6 μg C mg−1 AFDM day−1, accounting for 50% of the daily growth rate of the fifth instar larvae. 4. These results suggest that leaf material colonised by A. filiformis is a high quality food resource for P. gentilis larvae, and that fungal biomass can contribute significantly to the growth of these larvae. Differences in feeding behaviour and digestive physiology may explain the significantly greater assimilation of fungal biomass by the earlier instar than the final instar. To satisfy their nutritional needs the fifth instar larvae would have to assimilate detrital mass that may have been modified by fungal exoenzymes.
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leaf litter decomposition and microbial activity in nutrient enriched and unaltered reaches of a headwater stream
Freshwater Biology, 2003Co-Authors: Vladislav Gulis, Keller SuberkroppAbstract:SUMMARY 1. Decomposition of red maple (Acer rubrum) and rhododendron (Rhododendron maximum) leaves and activity of associated microorganisms were compared in two reaches of a headwater stream in Coweeta Hydrologic Laboratory, NC, U.S.A. The downstream reach was enriched with ammonium, nitrate, and phosphate whereas the upstream reach was not altered. 2. Decomposition rate, microbial respiration, fungal and bacterial biomass, and the sporulation rate of aquatic Hyphomycetes associated with decomposing leaf material were significantly higher for both leaf types in the nutrient-enriched reach. Species richness and community structure of aquatic Hyphomycetes also exhibited considerable changes with an increase in the number of fungal codominants in the nutrient-enriched reach. 3. Fungal biomass was one to two orders of magnitude greater than bacterial biomass in both reaches. Changes in microbial respiration rate corresponded to those in fungal biomass and sporulation, suggesting a primary role of fungi in leaf decomposition. 4. Nutrient enrichment increased microbial activity, the proportion of leaf carbon channelled through the microbial compartment and the decomposition rate of leaf litter.
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effect of dissolved nutrients on two aquatic Hyphomycetes growing on leaf litter
Fungal Biology, 1998Co-Authors: Keller SuberkroppAbstract:Concentrations of potassium nitrate, potassium phosphate, or calcium chloride were varied in stream-simulating microcosms containing leaf discs colonized by the aquatic Hyphomycetes Anguillospora filiformis or Lunulospora curvula. Cumulative conidium production of the fungi determined from rates of sporulation at 2 d intervals was stimulated by increasing concentrations of both potassium nitrate and potassium phosphate but not by calcium chloride. Leaf weight loss was also stimulated by increasing concentrations of potassium nitrate and potassium phosphate. The amount of fungal biomass (determined as ATP concentrations) associated with leaf discs increased significantly only in the treatments in which A. filiformis received increasing concentrations of potassium nitrate. These results indicate that as aquatic Hyphomycetes grow on leaf litter, they can obtain at least a portion of their inorganic nutrition from the water flowing over the leaves. They also suggest that sporulation is more sensitive to changes in nutrient concentrations than growth.
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Temperature and sporulation of aquatic Hyphomycetes
Applied and Environmental Microbiology, 1998Co-Authors: Eric Chauvet, Keller SuberkroppAbstract:Temperature appears to be an important factor affecting the occurrence and distribution of aquatic Hyphomycetes, the dominant leaf litter-decomposing fungi in streams. We compared conidium production by eight species of aquatic Hyphomycetes grown on yellow poplar leaves in stream-simulating microcosms at three temperatures (15, 20, and 25 degrees C). The greatest conidium production occurred at 15 degrees C for one species, 20 degrees C for two species, and 25 degrees C for two species. Two species produced similar numbers of conidia at 20 and 25 degrees C, and one species produced similar numbers of conidia at all three temperatures. Linear growth rates were determined on malt extract agar. Six species had the same pattern of temperature responses for growth on malt extract agar as for sporulation on leaves, as shown by the positive correlations between the two parameters at the three temperatures. The species examined also exhibited differences in number of conidia produced from a similar amount of leaf material at a given temperature. These differences appeared to be due primarily to differences in individual conidium mass (determined by weighing conidia produced from cultures), as shown by the relationship of the type Y = k/X (r = 0.96), where Y is the number of conidia produced, X is the individual conidium mass in milligrams, and k is a constant empirically determined to be 2.11. This finding supports the hypothesis that aquatic Hyphomycetes allocate similar amounts of their resources to reproduction but vary with respect how these resources are partitioned into reproductive units (conidia).
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relationships between growth and sporulation of aquatic Hyphomycetes on decomposing leaf litter
Fungal Biology, 1991Co-Authors: Keller SuberkroppAbstract:The dynamics of changes in microbial biomass (ATP concentrations), respiration rates and sporulation rates of aquatic Hyphomycetes associated with tulip poplar leaf disks in two streams with different water chemistry were compared with the activities of a dominant fungal species from each stream growing on sterilized leaf disks in the laboratory. Aquatic Hyphomycetes sporulated at maximum rates after 15–19 d in both stream and laboratory studies. Sporulation occurred during periods of increasing biomass and respiration indicating a close relationship between growth and sporulation in these fungi. Leaf disks decomposing in the hardwater stream supported greater biomass, activity and number of species than those decomposing in the softwaer stream. Fungi colonizing leaf disks in the laboratory exhibited higher ATP concentrations and sporulation rates than the communities from either stream. These differences appear to be related to water chemistry, particularly N and P concentrations. Organic matter budgets calculated for the two species grown in the laboratory indicated that growth yield coefficients were 0·15–0·23 g g −1 and net production efficiencies ranged from 24 to 46 %. A significant portion of fungal production was converted into conidia by both fungi.
Kevin D Hyde - One of the best experts on this subject based on the ideXlab platform.
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morphology and phylogeny reveal stemphylium dianthi sp nov and new host records for the sexual morphs of s beticola s gracilariae s simmonsii and s vesicarium from italy and russia
Phytotaxa, 2019Co-Authors: Rashika S Brahmanage, Dhanushka N Wanasinghe, M C Dayarathne, Rajesh Jeewon, Jiye Yan, Timur S Bulgakov, Erio Camporesi, Pattana Kakumyan, Kevin D HydeAbstract:In an investigation of related pleosporalean taxa collected from Italy and Russia, a novel species, Stemphylium dianthi and new host and geographical records of S. beticola , S. gracilariae , S. simmonsii and S. vesicarium are reported . Stemphylium is a genus of filamentous ascomycetes comprising plant pathogens and saprobes in the family Pleosporaceae. Our new species, S. dianthi is a dematiaceous hyphomycete, which can be distinguished from other Hyphomycetes as it forms phaeodictyospores based on the percurrent rejuvenation of its conidiophores, and apically swollen conidiogenous cells. The sexual morphs of S. gracilariae and S. vesicarium are new host records from Italy and Russia respectively. Stemphylium beticola from dead stem of Dianthus capitatus and S. simmonsii from Acer campestre are herein described from a natural host substrate for the first time. An updated phylogenetic tree for Stemphylium is constructed using multi-genes (ITS, gapdh and cmdA ) to confirm the phylogenetic relationships of Stemphylium species presented in this study. This paper provides morphological descriptions, illustrations and molecular data for each taxon.
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multi gene phylogenetic analyses reveals neohelicosporium gen nov and five new species of helicosporous Hyphomycetes from aquatic habitats
Mycological Progress, 2018Co-Authors: Saranyaphat Boonmee, Kevin D Hyde, Jiankui Liu, Eric H C Mckenzie, Prapassorn D Eungwanichayapant, Jichuan KangAbstract:Helicosporous Hyphomycetes are a morphologically allied group of Tubeufiales. We introduce a new helicosporous genus, Neohelicosporium, with five new species, Neohelicosporium aquaticum, N. guangxiense, N. hyalosporum, N. parvisporum, and N. thailandicum, based on morphological and phylogenetic evidence. The RPB2 protein gene data are provided to analyze their phylogeny in Tubeufiales. Phylogenetic analyses of combined ITS, LSU, RPB2, and TEF1α sequence data from 13 new isolates of Neohelicosporium provided evidence to support the establishment of the new taxa. The morphological characters of Neohelicosporium that differentiate it from other helicosporous species are compared and discussed.
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novel chaetosphaeriaceous Hyphomycetes from aquatic habitats
Mycological Progress, 2016Co-Authors: Jiankui Liu, Kevin D Hyde, Jing Yang, Sajeewa S N Maharachchikumbura, Eric H C Mckenzie, E Gareth B Jones, Zuoyi LiuAbstract:A survey of freshwater ascomycetes conducted in Thailand yielded a number of aquatic Hyphomycetes. In this study, fresh collections of three chaetosphaeriaceous species from submerged wood in freshwater are characterized based on morphology and molecular phylogeny. Dictyochaeta siamensis sp. nov. and Tainosphaeria siamensis sp. nov. are introduced based on morphological and molecular data. A detailed description of Menisporopsis theobromae from the new collection is presented and the first molecular data for this genus are provided. Phylogenetic analysis of combined LSU and ITS sequence data was carried out to determine the phylogenetic placement of these species within the family Chaetosphaeriaceae. Menisporopsis theobromae showed a close phylogenetic relationship with Rattania, but has significantly different morphology; D. siamensis clustered together with Codinaeopsis, Menispora, and Zignoella; while T. siamensis clustered together with T. crassiparies but presented as a distinct clade. The phylogenetic relationship between the new taxa and their relatives are compared and discussed.
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aquatic Hyphomycetes and litter decomposition in tropical subtropical low order streams
Fungal Ecology, 2016Co-Authors: Manuel A S Graca, Kevin D Hyde, Eric ChauvetAbstract:Leaf litter decomposition is an important ecosystem function carried out by a diverse array of consumers, including aquatic Hyphomycetes. Aquatic Hyphomycetes are found in streams worldwide, but their diversity and abundance varies across systems. In general, species diversity is lower across tropical and subtropical systems when compared with temperate biomes. The low diversity in tropical and subtropical areas may be related to: (a) lower seasonality; (b) our inability to detect fungi by traditional techniques; (c) low turbulence of rivers where many studies were carried out; (d) low nutrient content in many studied tropical systems; (e) leaves highly defended against consumers; and (1) competition from other decomposers. In terms of function, fungal biomass, sporulation rates and litter decomposition by aquatic Hyphomycetes in the tropics was reported to be equivalent to or much lower than observed in temperate zones. The feeding ecology of shredder invertebrates is strongly related to the presence of microbial decomposers in the environment. The lack of shredders reported for some tropical rivers may be related to a low microbial biomass, well defended tropical leaves and frequent hydrological events which remove leaves before they can be used by shredders. Seasonal variations in rain fall in tropical and subtropical systems are likely to affect litter fall, the identity and quality of litter, the reproduction of aquatic Hyphomycetes (due to turbulence effects) and therefore the community composition of aquatic Hyphomycetes throughout the year. Future research on aquatic Hyphomycetes and litter decomposition in the tropics and sub-tropics should address the diversity/identity gap, altitudinal gradient changes and the contribution of aquatic Hyphomycetes to the trophic ecology of shredders. (C) 2015 Elsevier Ltd and The British Mycological Society. All rights reserved.
Marc E. Savard - One of the best experts on this subject based on the ideXlab platform.
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the phylogenetic relationships of two trichothecene producing Hyphomycetes spicellum roseum and trichothecium roseum
Mycologia, 1997Co-Authors: Keith A Seifert, Gerry Louisseize, Marc E. SavardAbstract:The phylogenetic relationship between the Hyphomycetes Spicellum roseum and Trichothecium roseum was inferred from an analysis of partial se- quences of nuclear small (18S) and nuclear large (28S) ribosomal RNA subunits. Both analyses suggest that the two species form a monophyletic group al- lied with the Hypocreales but sister group relation- ships are unclear. Colony characters and trichothe- cene production also support the close relationship between these two species. However, differences in conidiophore branching and conidium ontogeny suggest the retention of separate anamorph genera is justified.