Fig 1 - uploaded by Dmytro Leontyev
Content may be subject to copyright.
General view of the fructifications of Alwisia bombarda. a-e. Sporocarps with emerging capillitial threads, free in the upper part but fused at the base to a common stalk. f. Iridescent threads of the capillitium attached to the lower portions of the peridium. Bars: a = 1 mm; b-d = 500 μm; e = 400 μm; f = 200 μm. Specimens: a-c: USJ 82221; d: UARK 30321; e-f: UARK 30628.
Source publication
We studied the capillitial structures produced in Alwisia bombarda (Reticulariaceae, Myxomycetes) by light and electron microscopy. This species develops tubular threads inside of clustered but still separate sporocarps with intact walls forming a cup. These threads have been
considered to be a pseudocapillitium for a long time, but they do not rep...
Contexts in source publication
Context 1
... all of the investigated specimens, the sporothecae are filled with a dense brush-like tuft of threads, directed outwards from the base of the sporotheca (Fig. 1). These threads appear straight, rigid, tubular, hollow, copper-brown (2.5YR2-3/2-4) in reflected light, weakly iridescent with blue, green and purple tints (Fig. 1f) but rust-brown (7.5YR3-5/7-10) in transmitted light (Fig. ...
Context 2
... all of the investigated specimens, the sporothecae are filled with a dense brush-like tuft of threads, directed outwards from the base of the sporotheca (Fig. 1). These threads appear straight, rigid, tubular, hollow, copper-brown (2.5YR2-3/2-4) in reflected light, weakly iridescent with blue, green and purple tints (Fig. 1f) but rust-brown (7.5YR3-5/7-10) in transmitted light (Fig. ...
Similar publications
We have performed an empirical comparison of two distinct notions of discrete Ricci curvature for graphs or networks, namely, the Forman-Ricci curvature and Ollivier-Ricci curvature. Importantly, these two discretizations of the Ricci curvature were developed based on different properties of the classical smooth notion, and thus, the two notions sh...
Citations
... The taxonomic spectrum of the local community is fundamentally influenced by the methods of detection of organisms e.g. season, duration and type of route (Leontyev et al., 2013;Yatsiuk et al., 2018), the species concept used (Leontyev & Fefelov, 2012;Leontyev et al., 2014) etc. Therefore, it is important to study taxonomic spectra using large checklists that integrate the results of long-term research carried out by different authors and using different methods. ...
Taxonomic spectra, i.e. relations between supraspecific taxa by the number of included species, remain poorly understood in aspect of the mathematical properties. We studied taxonomic spectra of plants (Magnoliophyta, Bryophyta), animals (Coleoptera, Aves), fungi (Agaricomycetes) and terrestrial protists (Myxomycetes), found in the Homilsha Forests National Nature Park (North-East of Ukraine), and concluded that they correspond to the hollow-curve distribution at the level of genera, families and orders. The spectra of most taxa, as shown by the Akaike information criterion, are closely approximated by the log-series distribution model at all taxonomic levels. This type of distribution is typical for the species abundance curves, based on collections made from small areas. At the same time, in the genera–families–orders row the similarity to the lognormal distribution increases. The central values and variability vary considerably between different taxonomic groups and ranks, however, without affecting the type of distribution. The number of orders in all taxa except Bryophyta has reached the saturation and coincides with the curve of the estimated number of orders according to the Chao1 coefficient. For families and especially genera the correspondence with estimated number of species is much lower. Our results do not confirm the assumption that hollow-curve distributions of taxonomic spectra result from the artificial fragmentation of taxa. These distributions neither depend on the insufficient knowledge about the species composition at the locality, nor reflect the size of the studied area. The presence of such distributions in both local and global biota of different groups may be explained by the common features of their evolution, especially by the existence of relict orphan groups. The fact that in Homilsha Forests the kurtosis and skewness of distributions decreases in the genera–families–orders row can therefore be explained by the relatively low percentage of the high-rank orphan taxa in the local biota. This may be a common feature of communities studied at small geographical scale, since orphan taxa often demonstrate a high level of endemism. Comparative studies of local communities from different climate zones may help to understand how universal are the patterns, described herein.
... The life cycle of these organisms includes stages of single-nucleus amoebae cells (myxamoebae), multi-nuclear amoeboids (plasmoids) and fruiting bodies (sporocarps), in which the spore mass is covered by noncellular membranous coating (Clark & Haskins, 2013;Stephenson & Schnittler, 2017). The identification of myxomycetes is based on investigation of spores and non-cellular elements of their fruiting bodies (Leontyev & Fefelov, 2012;Leontyev et al., 2014). According to contemporary views, myxomycetes belong to the Amoebozoa supergroup (Kang et al., 2017;Leontyev & Schnittler, 2017) that also contains most of the lobose amoebae and some heterotrophic flagellates (Adl et al., 2019). ...
Corticulous myxomycetes remain one of the least surveyed ecological groups of terrestrial protists. These organisms develop on the bark of trees, mostly feeding on bacteria and microalgae. Their microscopic size and fast developmental cycle (3–5 days) complicate the study of these organisms, and therefore data their on ecological relationships and patterns of biodiversity corticulous myxomycetes remain controversial. On the territory of the southwest spurs of the Central Russian Upland (Northeast Ukraine), no special studies on these organisms have been conducted. During 2017–2020, in nine forest sites located in this territory, we collected samples of bark of 16 species of tree plants, on which sporulating myxomycetes were then identified using the moist chamber technique in laboratory conditions. A total of 434 moist chambers was prepared, and 267 (61.5%) of which were found to contain myxomycete fruiting bodies. In total, we made 535 observations, finding 20,211 sporocarps. As a result, in the surveyed territory, we found 38 species of corticulous myxomycetes, belonging to 18 genera, 10 families, 7 orders, and 2 subclasses of Myxomycetes. Among the species of corticulous myxomycetes, the most abundant were Echinostelium minutum, Arcyria pomiformis, Macbrideola cornea, Perichaena chrysosperma, Licea kleistobolus, Paradiacheopsis fimbriata, Cribraria violacea, Enerthenema papillatum, A. cinerea, and L. operculata. The greatest species richness in the examined biota was observed for genera Comatricha, Licea, Paradiacheopsis and Perichaena, families Amaurochaetaceae and Trichiaceae, orders Stemonitidales, Trichiales and Physarales. By species diversity, dark-spored myxomycetes (Collumellomycetidae) somewhat exceeded bright-spored myxomycetes (Lucisporomycetidae). Badhamia versicolor, Didymium dubium, D. sturgisii, Macbrideola decapillata, and Perichaena luteola are new species for the surveyed area. Four species of myxomycetes were collected in Ukraine for the first time: Hemitrichia pardina, Licea floriformis, L. pygmea, and Macbrideola argentea. Quantitative and qualitative structure of myxomycete consortia developing on different species of substrate-forming plants demonstrated significant differences. The highest level of similarity was demonstrated by Fraxinus excelsior and Acer platanoides, and a relatively strong relationship was seen between Pinus sylvestris and Tilia cordata. The central cluster comprised F. excelsior, A. platanoides and P. sylvestris. By the sum of values of Bray-Curtis coefficient, Quercus robur appeared to be most distinctive plant species by quantitative composition of myxomycete consortia. F. excelsior and T. cordata are the most favourable for the development of corticulous myxomycetes. In all the analyzed consortia, the dominant species belonged to the Stemonitidales and Trichiales orders, while the remaining orders were represented by notably fewer species. Relative species richness of Stemonitidales was the highest in consortia of P. sylvestris, the contribution of Liceales was the greatest in A. platanoides and P. sylvestris, the percentage of Echinosteliales and Physarales was the highest on F. excelsior, the share of Cribrariales was especially large on A. platanoides. Trichiales were represented on all the analyzed substrates to almost the same extent. Representatives of Cribrariales and Physarales were completely absent on P. sylvestris, the species of Clastodermatales – on all species of plants, except Q. robur. Prevalence of bright-spored myxomycetes was determined for consortia of Acer platanoides, the dominance of dark-spored myxomycetes – for F. excelsior, P. sylvestris and Q. robur. The obtained data indicate the presence of stable complexes of corticulous myxomycetes, associated with different species of trees in the forest ecosystems of Northeast Ukraine. This encourages further study of the structure of myxomycete consortia with tree species that were not included in this study and determining the influence of physical-chemical properties of the bark of different plant species on the discovered peculiarities of myxomycete communities.
... Even the limited phylogenetic data currently available support the conclusion that some very conspicuous characters traditionally considered as important for the classification of myxomycetes have evolved several times independently. This is the case for both the formation and reduction of the stalk and the capillitium, the crystallization of lime deposits, and the evolution of compound fruiting bodies (Leontyev et al. 2014, Leontyev & Schnittler 2017. All of these characters were used in the traditional system of classification to delimit genera, families and even orders (as was the case for the order Liceales s. l., which was characterized by the absence of capillitium). ...
This article provides an outline of the classification of the kingdom Fungi (including fossil fungi. i.e. dispersed spores, mycelia, sporophores, mycorrhizas). We treat 19 phyla of fungi. These are Aphelidiomycota, Ascomycota, Basidiobolomycota, Basidiomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Entorrhizomycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. The placement of all fungal genera is provided at the class-, order- and family-level. The described number of species per genus is also given. Notes are provided of taxa for which recent changes or disagreements have been presented. Fungus-like taxa that were traditionally treated as fungi are also incorporated in this outline (i.e. Eumycetozoa, Dictyosteliomycetes, Ceratiomyxomycetes and Myxomycetes). Four new taxa are introduced: Amblyosporida ord. nov. Neopereziida ord. nov. and Ovavesiculida ord. nov. in Rozellomycota, and Protosporangiaceae fam. nov. in Dictyosteliomycetes. Two different classifications (in outline section and in discussion) are provided for Glomeromycota and Leotiomycetes based on recent studies. The phylogenetic reconstruction of a four-gene dataset (18S and 28S rRNA, RPB1, RPB2) of 433 taxa is presented, including all currently described orders of fungi.
... 2i, 3k, 4j; see also fig. 2I-L in Leontyev et al. 2014b). These similarities suggest that the columella of Siphoptychium may appear nothing other than one capillitial tube that remained within the sporotheca when the latter became very narrow after compound fructifications evolved. ...
The genus Siphoptychium is resurrected on the basis of comparative morphology and phylogeny of partial nuc 18S rDNA (18S) and translation elongation factor 1-alpha (EF1A) nucleotide sequences. The genus is characterized by the firm upper surface of the pseudoaethalium, accreted but easily separable sporothecae, a tubular or fibrous columella, and spores with a reticulate ornamentation consisting of 7–9 meshes across the diameter. In addition to the currently known single species S. casparyi (= Tubifera casparyi), two new members of Siphoptychium are described: S. violaceum from coniferous forests of Europe, east Asia, and southeast Asia, and S. reticulatum from temperate and subarctic regions of North America and alpine regions of Europe. A second genus, Thecotubifera, is described to accommodate Tubifera dictyoderma. The fruiting body of this species is transitional between a pseudoaethalium and a true aethalium. It is covered by a contiguous membranous cortex formed by the fused tips of the sporothecae, a feature typical for aethalia. However, the inner portions of sporothecae remain discernible, a feature more typical for pseudoaethalia. Columellae of Th. dictyoderma are formed by perforated plates, and the spores have a reticulate ornamentation consisting of 2–5 meshes across the diameter. For Th. dictyoderma, we could confirm records only for tropical regions and Japan, whereas all studied European specimens, including those mentioned in current monographs, represent species of Siphoptychium.
... This group includes all bright-spored taxa except for members of the Cribrariaceae, which lack a capillitium. Therefore, the synapomorphy of Trichiidia may be the presence of a tubular capillitium (Leontyev et al. 2014c). In the Trichiidia this structure may have evolved independently from that present in the dark-spored myxomycetes (see Fig. 3 below). ...
... remains difficult. Partial 18S rDNA sequences of L. epidendtum show a high molecular diversity (Leontyev et al. 2014c) and seem to confirm the assumption of Ing (1999) that this represents a species complex. The traditional circumscription of the fruiting bodies of Lycogala as aethalia and its tubular threads as pseudocapillitium was criticized on the basis of ontogenetic studies (McHugh and Reid 2008) and comparative morphology . ...
... • (Leontyev et al. 2014c, Eliasson 2017 suggest that this character is insufficient to warrant the separation of this taxon into a separate genus. ...
The traditional classification of the Myxomycetes (Myxogastrea) into five orders (Echinosteliales, Liceales, Trichiales, Stemonitidales and Physarales), used in all monographs published since 1945, does not properly reflect evolutionary relationships within the group. Reviewing all published phylogenies for myxomycete subgroups together with a 18S rDNA phylogeny of the entire group serving as an illustration, we suggest a revised hierarchical classification, in which taxa of higher ranks are formally named according to the International Code of Nomenclature for algae, fungi and plants. In addition, informal zoological names are provided. The exosporous genus Ceratiomyxa, together with some protosteloid amoebae, constitute the class Ceratiomyxomycetes. The class Myxomycetes is divided into a bright-and a dark-spored clade, now formally named as subclasses Lucisporomycetidae and Columellomycetidae, respectively. For bright-spored myxomycetes, four orders are proposed: Cribrariales (considered as a basal group), Reticulariales, a narrowly circumscribed Liceales and Trichiales. The dark-spored myxomycetes include five orders: Echinosteliales (considered as a basal group), Clastodermatales, Meridermatales, a more narrowly circumscribed Stemonitidales and Physarales (including as well most of the traditional Stemonitidales with durable peridia). Molecular data provide evidence that conspicuous morphological characters such as solitary versus compound fructifications or presence versus absence of a stalk are overestimated. Details of the capillitium and peridium, and especially how these structures are connected to each other, seem to reflect evolutionary relationships much better than many characters which have been used in the past.
... Finally, the third lineage joins Alwisia with the phylogenetic cluster, which unites Lycogala, Thecotubifera and Reticularia. The consequence of branching of this contemporary genera from Alwisia-like ancestor is not yet clear; however, taking into account the attribution of sporophores of Lycogala to the free sporocarps (Leontyev et al., 2014c), this genus appears to be the most «archaic» representative of the group. This is noteworthy that among Lycogala, Thecotubifera and Reticularia, the only first genus has the tubular capillitium, close in its morphology, ultrastructure and ontogenesis to that of Alwisia. ...
Recent molecular studies have clarified the phylogenetic relations within the family Reticulariaceae (Myxomycetes, Myxogastrea), allowing to reconstruct the ways of the morphological evolution within the family. We conclude, that the general tendency of the sporophore evolution in Reticulariaceae was the transformation of the stalked forms to the sessile ones, followed by the development of the metameric sporophores, called pseudoaethalia and aethalia, from the separate sporocarps. The common ancestor of the family was similar to Alwisia lloydiae having stalked sporocarps and tubular capillitium. At least four evolutionary lineages originated form this ancestor: 1) Alwisia → Tubifera, 2) Alwisia → Rigidotubula (and probably Siphoptychium), 3) Alwisia → (Lycogala) → Thecotubifera, 4) Alwisia → Lycogala → Reticularia. In each of these branches, the processes like a loss of stalks, transition from spherical to elongated sporothecae, transformation of solitary sporocarps to grouped ones, a loss of capillitium and formation of pseudocapillitium, have occurred independently. Therefore, the type of the fruiting body, and presence of capillitium or pseudocapillitium, cannot be considered as sufficient criteria for separating myxomycete genera.
... Although molecular studies are likely to remain the most important tool for defining phylogenetic relations among taxa of myxomycetes, further structural and ontogenetic studies should be encouraged to clarify the origin of capillitial or capillitium-like structures in genera such as, for example, Lycogala and Reticularia. Although a socalled pseudocapillitium has traditionally been interpreted as remains of a reduced peridium, its true origin may sometimes be questioned (Eliasson 1977(Eliasson , 2011, and as shown in a recent study of Alwisia (Leontyev et al. 2014) the interpretation of capillitial structures also has a bearing on the interpretation of the structure and type of the fruitbody. ...
Genera and species of myxomycetes have been based traditionally on morphological features of the fruitbodies (sporocarps). Certain species bridge the gap between two genera by combining morphological characters, such as is the case for Hemitrichia leiocarpa, which combines characters of Hemitrichia and Arcyria and could equally well be placed in either genus on morphological grounds. A few species of Physarum and Badhamia combine characters of both genera. Molecular investigations are today a powerful tool for investigating evolutionary relationships, and there is molecular evidence that the two physaraceous genera mentioned above can no longer be maintained as presently circumscribed. Paraphyly has been demonstrated in the Stemonitales and additional molecular data are likely to necessitate changes in the circumscription of some genera. Certain species of Licea and Perichaena have minute sporocarps with simple morphology. Smaller sporocarps of some species of Perichaena may lack a capillitium and be morphologically similar to species of Licea, which blurs the line of separation between these two genera. The genus Licea remains enigmatic and is almost certainly unnatural, even after the removal of L. fimicola to a separate genus. Additional molecular investigations are necessary to elucidate the relationships among the different species.
In the second decade of the 20th century, Lycogala flavofuscum aethalia were collected in Brazil by Rev. Johannes Rick. Despite being easily observed in the field because of the size of the aethalia, the species was only found again in 2019, on a live trunk of Sebastiania commersoniana (branquilho, Euphorbiaceae) in the municipality of São Gabriel, Rio Grande do Sul, Brazil. The description and illustration of recently collected material, and data on exsiccates collected by Rick from Brazil, deposited at Herbarium BPI, are presented herein. Information on substrates, microhabitats, and geographic distribution of the species in the Neotropics is provided based on bibliographical sources and herbarium catalogs. Considering the large time interval between records and the restricted area of occurrence in the country, its inclusion as near threatened in the Brazilian Red List is recommended.
Early phylogenetic studies refuted most previous assumptions concerning the evolution of the morphological traits in the fruiting bodies of the order Trichiales and did not detect discernible evolutionary patterns, yet they were based on a limited number of species. We infer a new Trichiales phylogeny based on three independently inherited genetic regions (nuclear and mitochondrial), with a fair taxonomic sampling encompassing its broad diversity. Besides, we study the evolutionary history of some key morphological characters. According to the new phylogeny, most fruiting body traits in Trichiales systematics do not represent exclusive synapomorphies or autapomorphies for most monophyletic groups. Instead, the evolution of the features derived from the peridium, stalk, capillitium, and spores showed intricate patterns, and character state transitions occurred rather within- than between clades. Thus, we should consider other evolutionary scenarios instead of assuming the homology of some characters. According to these results, we propose a new classification of Trichiales, including the creation of a new genus, Gulielmina, the resurrection of the family Dictydiaethaliaceae and the genus Ophiotheca, and the proporsal of 13 new combinations for species of the genera Arcyria (1), Hemitrichia (2), Ophiotheca (2), Oligonema (4), Gulielmina (3), and Perichaena (1).
