Ontogenetic comparisons of arbuscular mycorrhizal fungi Scutellospora heterogama and Scutellospora pellucida: revision of taxonomic character concepts, species descriptions, and phylogenetic hypotheses

1994 ◽  
Vol 72 (1) ◽  
pp. 122-134 ◽  
Author(s):  
Marlise Franke ◽  
Joseph Morton
Keyword(s):  
Mycorrhizal Fungi ◽  
Cladistic Analysis ◽  
Arbuscular Mycorrhizal ◽  
Morphological Characters ◽  
Spore Wall ◽  
Developmental Patterns ◽  
Quantitative Properties ◽  
Temporal And Spatial ◽  
Phylogenetic Hypotheses ◽  
Species Descriptions

The taxonomic significance of morphological characters in fungi of Glomales (Zygomycetes) has been based solely on superficial resemblance. Ontogenetic comparisons among isolates of Scutellospora pellucida and Scutellospora heterogama were used to resolve discrete stages of differentiation in which characters were delimited and ordered hierarchically according to temporal and spatial origin in development. Character concepts were revised, and both species were redescribed. A spore wall, two inner walls, and a germination shield were designated primary characters because they appeared separately and in linear succession. Secondary characters included distinct layers differentiated within each wall. Tertiary characters were qualitative and quantitative properties of each layer. All characters in each developmental stage did not vary in two hosts, in separate experiments, and among five isolates of each species. Stability was attributed to causal epigenetic linkages between stages of differentiation, wherein each new stage depended on differentiation of all characters in the preceding stage. Characters at successively lower hierarchical levels are predicted to specify progressively less inclusive taxa in cladistic analysis. Developmental patterns will improve reinterpretations of phylogenetic relationships and provide a more empirical basis for grouping and ranking of organisms into species and higher taxa at the morphological level. Key words: evolution, morphology, mycorrhizae, taxonomy, VAM fungi.

Dominikia duoreactiva sp. nov. and Dominikia difficilevidera sp. nov., two new species in the Glomeromycota

Botany ◽  
2015 ◽  
Vol 93 (7) ◽  
pp. 389-396 ◽  
Author(s):  
Janusz Błaszkowski ◽  
Gerard Chwat ◽  
Sarah Symanczik ◽  
Anna Góralska
Keyword(s):  
New Species ◽  
Mycorrhizal Fungi ◽  
National Park ◽  
Phylogenetic Analyses ◽  
Arbuscular Mycorrhizal ◽  
Morphological Characters ◽  
Spore Wall ◽  
Worldwide Distribution ◽  
Two New Species ◽  
Dune Plants

Two new species of arbuscular mycorrhizal fungi (AMF) of the recently erected genus Dominikia (Glomeromycota) are described based on their morphology and phylogenetic analyses of SSU–ITS–LSU sequences. The distinctive morphological characters of the first species, Dominikia duoreactiva sp. nov., is the formation of loose clusters with yellow-coloured, 30–70 μm diameter spores having a three-layered spore wall, of which layers 1 and 3 stain in Melzer’s reagent. The second species, Dominikia difficilevidera sp. nov., is distinguished by its hyaline, 31–45 μm diameter spores, which arise mainly singly and have a three-layered spore wall, of which layer 1 is thicker than the structural laminate layer 2, and layer 3 is flexible to semi-flexible. Both species were originally associated with maritime dune plants; D. duoreactiva comes from the Giftun Island, Egypt, Africa, and D. difficilevidera from the Słowiński National Park, Poland. Based on available data, we suggest D. duoreactiva occurs rarely in the world, and D. difficilevidera has a worldwide distribution, but it either occurs infrequently or has been overlooked or lost during spore extraction from soils of many sites because of its extremely small and hyaline spores. A method allowing the extraction of even the smallest spores of AMF, but observable under a dissecting microscope, is described.

scholarly journals Bacteria Associated with Spores of the Arbuscular Mycorrhizal Fungi Glomus geosporum and Glomus constrictum

2005 ◽  
Vol 71 (11) ◽  
pp. 6673-6679 ◽  
Author(s):  
David Roesti ◽  
Kurt Ineichen ◽  
Olivier Braissant ◽  
Dirk Redecker ◽  
Andres Wiemken ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Plantago Lanceolata ◽  
Arbuscular Mycorrhizal ◽  
Spore Wall ◽  
Wall Layer ◽  
Single Spore ◽  
Bacterial Populations ◽  
Glomus Geosporum

ABSTRACT Spores of the arbuscular mycorrhizal fungi (AMF) Glomus geosporum and Glomus constrictum were harvested from single-spore-derived pot cultures with either Plantago lanceolata or Hieracium pilosella as host plants. PCR-denaturing gradient gel electrophoresis analysis revealed that the bacterial communities associated with the spores depended more on AMF than host plant identity. The composition of the bacterial populations linked to the spores could be predominantly influenced by a specific spore wall composition or AMF exudate rather than by specific root exudates. The majority of the bacterial sequences that were common to both G. geosporum and G. constrictum spores were affiliated with taxonomic groups known to degrade biopolymers (Cellvibrio, Chondromyces, Flexibacter, Lysobacter, and Pseudomonas). Scanning electron microscopy of G. geosporum spores revealed that these bacteria are possibly feeding on the outer hyaline spore layer. The process of maturation and eventual germination of AMF spores might then benefit from the activity of the surface microorganisms degrading the outer hyaline wall layer.

Ammonites phylogenetic analysis: state of the art and new prospects

2004 ◽  
Vol 175 (5) ◽  
pp. 507-512 ◽  
Author(s):  
Isabelle Rouget ◽  
Pascal Neigeet ◽  
Jean-Louis Dommergues
Keyword(s):  
Phylogenetic Reconstruction ◽  
Cladistic Analysis ◽  
Relative Weight ◽  
Morphological Characters ◽  
Quality Of Data ◽  
Phylogenetic Studies ◽  
Evolutionary Concepts ◽  
Phylogenetic Hypotheses ◽  
Definition Of ◽  
Iterative Evolution

Abstract Two main types of data are available to resolve phylogenies using fossils data: (1) stratigraphic ordering of taxa, and (2) morphological characters. In most phylogenetic studies dealing with ammonites, authors have given priority to the stratigraphic distribution of taxa. This practice is classically justified by the fact that the ammonite fossil record is frequently outstandingly good. In practice, the level of integration of stratigraphic and morphologic information in a single analysis depends on the confidence that authors have in the quality of data. Besides, many evolutionary concepts, which could differ over time and between authors (e.g. anagenesis, cladogenesis, iterative evolution), are added to these data to help infer phylogenetic relationships. As a result, phylogenetic hypotheses are based on eclectic methods which depend on the relative weight given to stratigraphic and morphologic information as well as on evolutionary concepts used. The validity of relationships proposed by previous authors is not dealt with in this paper. Instead, our goal is to draw attention to problems that these eclectic methods may cause, that is to say: (1) ammonites systematics is poorly formalised and (2) phylogenetic hypotheses as they are classically constructed are not rigorously testable. During the last 10 years, cladistic analysis has been applied to ammonites but is still unpopular among ammonitologists. However, studies have consistently shown that cladistics is not as unsuited a tool for ammonites phylogenetic reconstruction as is widely believed. Moreover, classical works open new questions about ammonite phylogeny and in particular, help to reappraise our view on the definition of morphological characters and their phylogenetic significance.

Phylogeny, Molecules Versus Morphology, and Rates of Character Evolution Among Fruitbats (Chiroptera: Megachiroptera)

1995 ◽  
Vol 43 (6) ◽  
pp. 557 ◽  
Author(s):  
MS Springer ◽  
LJ Hollar ◽  
JAW Kirsch
Keyword(s):  
Cladistic Analysis ◽  
Strong Support ◽  
Morphological Characters ◽  
Character Evolution ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Minimum Length ◽  
Data Set ◽  
Dna Hybridisation ◽  
Phylogenetic Hypotheses

Andersen's 1912 monograph on megachiropterans remains the definitive work on the systematics of this group. Andersen argued that the Macroglossinae, containing the eonycterine and notopterine sections, are a monophyletic sister-group to other fruitbats (i.e. Andersen's Rousettus, Cynopterus and Epomophorus sections). Two recent molecular studies (DNA hybridisation and restriction mapping of ribosomal cistrons), as well as an analysis of female reproductive characters, challenge the monophyly of the Macroglossinae and several of Andersen's other conclusions such as the phylogenetic position of Nyctimene. We performed a cladistic analysis on 36 morphological characters, including 33 that were gleaned from Andersen, to determine whether phylogenetic hypotheses based on modem phylogenetic methods are in agreement with Andersen's original conclusions and to compare morphological and molecular phylogenetic hypotheses. Minimum-length trees based on parsimony are largely consistent with Andersen and support (1) a monophyletic Macroglossinae, within which the eonycterine section is paraphyletic with respect to a monophyletic notopterine section, (2) a monophyletic Cynopterus section, excepting the exclusion of Myonycteris, (3) a monophyletic Epomophorus section, excepting the exclusion of Plerotes, and (4) a paraphyletic Rousettus section, with several of the Rousettus-like forms branching off near the base of the tree. Bootstrapping analyses on a reduced data-set that included taxa shared in common with the DNA hybridisation study did not provide strong support (greater than or equal to 95%) for any clades but did provide moderate support (greater than or equal to 70) for several clades, including a monophyletic Macroglossinae. These findings are in marked contrast to the DNA hybridisation phylogeny. A high index of between-data-set incongruence is further evidence for the clash between DNA hybridisation and morphology. A phylogenetic framework was constructed on the basis of morphological data and DNA hybridisation data using a criterion of moderate support and shows little resolution, whereas employing a criterion of strong support produced a framework resolving several additional nodes. One implication of this framework is that characteristic macroglossine features such as a long tongue with a thick carpet of filiform papillae have evolved independently on several occasions (or evolved once and were lost several times). Rates of character evolution for the morphological characters employed in our analysis were calculated using divergence times estimated from DNA hybridisation data. Rates have apparently been fastest in the interior branches, and slower along the external branches, which suggests an early adaptive radiation in the history of fruitbats.

scholarly journals In-depth phylogenomic analysis of arbuscular mycorrhizal fungi based on a comprehensive set of de novo genome assemblies

2021 ◽  
Author(s):  
Merce Montoliu-Nerin ◽  
Marisol Sánchez-García ◽  
Claudia Bergin ◽  
Verena Esther Kutschera ◽  
Hanna Johannesson ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
De Novo ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Sister Group ◽  
Morphological Characters ◽  
Nuclear Ribosomal Dna ◽  
Phylogenomic Analysis ◽  
Wide Range ◽  
Genome Assemblies

Morphological characters and nuclear ribosomal DNA (rDNA) phylogenies have so far been the basis of the current classifications of arbuscular mycorrhizal (AM) fungi. Improved understanding of the phylogeny and evolutionary history of AM fungi requires extensive ortholog sampling and analyses of genome and transcriptome data from a wide range of taxa. To circumvent the need for axenic culturing of AM fungi we gathered and combined genomic data from single nuclei to generate de novo genome assemblies covering seven families of AM fungi. Comparative analysis of the previously published Rhizophagus irregularis DAOM197198 assembly confirm that our novel workflow generates high-quality genome assemblies suitable for phylogenomic analysis. Predicted genes of our assemblies, together with published protein sequences of AM fungi and their sister clades, were used for phylogenomic analyses. Based on analyses of sets of orthologous genes, we highlight three alternative topologies among families of AM fungi. In the main topology, Glomerales is polyphyletic and Claroideoglomeraceae, is the basal sister group to Glomeraceae and Diversisporales. Our results support family level classification from previous phylogenetic studies. New evolutionary relationships among families where highlighted with phylogenomic analysis using the hitherto most extensive taxon sampling for AM fungi.

Phylogeny and evolution of calcareous sponges

2006 ◽  
Vol 84 (2) ◽  
pp. 225-241 ◽  
Author(s):  
M Manuel
Keyword(s):  
Molecular Phylogeny ◽  
Phylogenetic Reconstruction ◽  
Cladistic Analysis ◽  
Morphological Characters ◽  
Calcareous Sponges ◽  
Rdna Sequences ◽  
Phylogenetic Hypotheses ◽  
Phylogeny And Evolution ◽  
High Level ◽  
The 19Th Century

The most recent advances concerning the phylogeny and evolution of calcareous sponges (Calcarea or Calcispongia) are reviewed here, in the light of the history of taxonomy of the group and conceptions about its evolution, starting from Haeckel's works at the end of the 19th century. Calcisponge phylogeny has recently started to be addressed using modern tools of phylogenetic reconstruction: cladistic analysis of morphological characters and molecular phylogeny (so far using 18S and 28S rDNA sequences). The monophyly of calcareous sponges is strongly supported in these works, as is their subdivision into two clades, Calcinea (whose proposed synapomorphy is the basal position of nuclei in choanocytes, with no relation to the flagella) and Calcaronea (whose possible synapomorphy is the formation of the amphiblastula larva through the original process of eversion of the stomoblastula). While the molecular phylogeny of Calcinea is still in its infancy because of insufficient taxonomic sampling, several lines are emerging for the phylogeny of Calcaronea, and these are in strong disagreement with the classification issued from the "traditional" morphological approach. Phylogenetic hypotheses also permit the reconstruction of morphological character evolution, which appears complex and subject to a high level of homoplasy.

Systematics, phylogeny and historical biogeography of the Pentagonaster clade (Asteroidea:Valvatida:Goniasteridae)

2007 ◽  
Vol 21 (4) ◽  
pp. 311 ◽  
Author(s):  
Christopher Mah
Keyword(s):  
Cladistic Analysis ◽  
Morphological Characters ◽  
Valid Species ◽  
Adult Size ◽  
Fossil Species ◽  
The Pacific ◽  
La Meseta Formation ◽  
Phylogenetic Hypotheses ◽  
Three New Species ◽  
Cope’S Rule

Morphology-based phylogenetic hypotheses developed for living and fossil goniasterid asteroids have provided several unique opportunities to study bathymetric and biogeographic shifts for an ecologically important group of prominent, megafaunal invertebrates. A cladistic analysis of 18 ingroup taxa employing 65 morphological characters resulted in a single most parsimonious tree. The tree supports assignment of the Atlantic Tosia parva (Perrier, 1881) and the Pacific Tosia queenslandensis Livingstone, 1932 to new, separate genera. The phylogenetic tree supports offshore to onshore bathymetric shifts between basal and derived taxa. The phylogeny is also consistent with historical events surrounding the separation of Antarctica from Australia and South Africa. Buterminaster Blake & Zinsmeister, 1988 from the Eocene La Meseta Formation, Antarctic Peninsula, was included in the phylogenetic analysis and is now supported as the only fossil species in the genus Pentagonaster Gray, 1840. Pentagonaster stibarus H. L. Clark, 1914 is separated from synonymy with P. dubeni Gray, 1847 and resurrected as a valid species. The new genus, Akelbaster, gen. nov., shows unusual new structures that resemble cribiform organs, although their function has not been determined. One specific ingroup lineage, including Tosia and Pentagonaster, attains a much larger adult size than those of its sister-taxa, suggesting that Cope’s rule may apply to asteroids within this clade. Pentagonaster and related genera are revised. Descriptions of four new genera and three new species are presented, including: Akelbaster novaecaledoniae, gen. nov., sp. nov., Ryukuaster onnae, gen. nov., sp. nov., Eknomiaster beccae, sp. nov., Pawsonaster parvus, gen. nov., comb. nov. and Anchitosia queenslandensis, gen. nov., comb. nov.

scholarly journals In-depth Phylogenomic Analysis of Arbuscular Mycorrhizal Fungi Based on a Comprehensive Set of de novo Genome Assemblies

2021 ◽  
Vol 2 ◽  
Author(s):  
Merce Montoliu-Nerin ◽  
Marisol Sánchez-García ◽  
Claudia Bergin ◽  
Verena Esther Kutschera ◽  
Hanna Johannesson ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
De Novo ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Sister Group ◽  
Morphological Characters ◽  
Nuclear Ribosomal Dna ◽  
Phylogenomic Analysis ◽  
Wide Range ◽  
Genome Assemblies

Morphological characters and nuclear ribosomal DNA (rDNA) phylogenies have so far been the basis of the current classifications of arbuscular mycorrhizal (AM) fungi. Improved understanding of the evolutionary history of AM fungi requires extensive ortholog sampling and analyses of genome and transcriptome data from a wide range of taxa. To circumvent the need for axenic culturing of AM fungi we gathered and combined genomic data from single nuclei to generate de novo genome assemblies covering seven families of AM fungi. We successfully sequenced the genomes of 15 AM fungal species for which genome data was not previously available. Comparative analysis of the previously published Rhizophagus irregularis DAOM197198 assembly confirm that our novel workflow generates genome assemblies suitable for phylogenomic analysis. Predicted genes of our assemblies, together with published protein sequences of AM fungi and their sister clades, were used for phylogenomic analyses. We evaluated the phylogenetic placement of Glomeromycota in relation to its sister phyla (Mucoromycota and Mortierellomycota), and found no support to reject a polytomy. Finally, we explored the phylogenetic relationships within Glomeromycota. Our results support family level classification from previous phylogenetic studies, and the polyphyly of the order Glomerales with Claroideoglomeraceae as the sister group to Glomeraceae and Diversisporales.

scholarly journals Glomus eburneum and Scutellospora fulgida, species of arbuscular mycorrhizal fungi (Glomeromycota) new for Europe

2013 ◽  
Vol 43 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Janusz Błaszkowski ◽  
Beata Czerniawska
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Morphological Characters ◽  
The World ◽  
Scutellospora Fulgida

Morphological characters of spores and mycorrhizae of <em>Glomus eburneum</em> and spores of <em>Scutellospora fulgida</em>, arbuscular mycorrhizal fungi of the phylum Glomeromycota, are described and illustrated. Additionally, the known distribution of these species in both Poland and other regions of the world is presented. Both species were not earlier reported from Europe.

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