scholarly journals Phenotypic plasticity of wall ultrastructure in the green alga Pediastrum s.l. (Chlorophyta, Sphaeropleales)

2016 ◽  
Vol 61 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Joanna Lenarczyk ◽  
Konrad Wołowski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phenotypic Plasticity ◽  
Green Alga ◽  
Phylogenetic Relationships ◽  
Diagnostic Character ◽  
Sem Micrographs ◽  
Wall Ultrastructure ◽  
Scanning Electron

Abstract This study examined wall ultrastructure variability in the microscopic green alga Pediastrum s.l. Its value as a diagnostic character is discussed. Field and cultured material of 21 taxa were compared using light and scanning electron microscopy. Nine ultrastructural elements occurring on the surface of Pediastrum are documented with LM and SEM micrographs. The highest number of taxa showed reticulate ornamentation composed of a trigonal mesh and granules situated on its corners. The paper considers the use of wall ultrastructure to reconcile traditional and modern taxonomical systems with regard to Pediastrum varieties, and addresses the phylogenetic relationships between strains representing different varieties.

Variation in the morphology of the dorsal and dorso-lateral tegument of male Schistosoma haematobium from southern Africa

1990 ◽  
Vol 64 (4) ◽  
pp. 323-329 ◽  
Author(s):  
F. J. Kruger ◽  
C. T. Wolmarans
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phenotypic Plasticity ◽  
Southern Africa ◽  
Schistosoma Haematobium ◽  
Scanning Electron

ABSTRACTThe teguments of Schistosoma haematobium males from three localities in the Eastern Transvaal and one in the eastern Caprivi were studied by means of scanning electron microscopy. Eastern Transvaal S. haematobium, which occurs sympatrically with S. mattheei, a bovine schistosome also infecting man and which hybridizes with S. haematobium, exhibited certain S. mattheei characteristics. The occurrence of these characteristics were neither related to the prevalence of human S. mattheei infections nor could they be attributed exclusively to phenotypic plasticity. The variation therefore may be geographical and possibly related to the phylogeny of the two species.

Anatomical characterisation of the foliar colleters in Myrtoideae (Myrtaceae)

2012 ◽  
Vol 60 (8) ◽  
pp. 707 ◽  
Author(s):  
Cleber J. da Silva ◽  
Luiz Cláudio de A. Barbosa ◽  
Ana E. Marques ◽  
Maria Cristina Baracat-Pereira ◽  
Antônio L. Pinheiro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phylogenetic Relationships ◽  
External Morphology ◽  
Secretory Structures ◽  
Reproductive Shoot ◽  
Sds Page ◽  
Histochemical Tests ◽  
Five Tribes ◽  
Scanning Electron

Colleters are secretory structures that occur in vegetative or reproductive shoot apices of many botanical families. However, in the order Myrtales, reports of colleters have considered only external morphology. We therefore evaluated apical meristems of 52 species belonging to 17 genera from seven tribes of subfamily Myrtoideae (Myrtaceae), so as to analyse the incidence and morphological types of colleters. The samples were fixed for light and scanning electron microscopy. Histochemical tests were carried out on fresh and methacrylate-embedded material. Proteins of the colleter secretions were analysed by SDS-PAGE. We have classified and described the following three new colleter types: petaloid, conic and euryform. None of the species contained all three colleter types. The petaloid colleters were present in three tribes (Syzygieae, Melaleuceae and Lophostemoneae). The conic colleters were observed in three tribes (Leptospermeae, Myrteae and Melaleuceae) and the euryform type occurred in five tribes (Leptospermeae, Syncarpieae, Myrteae, Syzygieae and Melaleuceae). In the tribe Eucalypteae, we found no evidence of colleters. The presence of mucilaginous secretion that defines colleters was confirmed by histochemical tests, and no proteins were found in the secretion. The colleters in Myrtoideae may help clarify the phylogenetic relationships of the Myrtaceae family.

The status and distribution of Carex subimpressa (Cyperaceae)

1986 ◽  
Vol 64 (1) ◽  
pp. 227-232 ◽  
Author(s):  
A. A. Reznicek ◽  
P. M. Catling
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Natural Populations ◽  
Field Studies ◽  
Diagnostic Character ◽  
Wide Area ◽  
Hybrid Origin ◽  
The Status ◽  
Specific Rank ◽  
Scanning Electron

Carex subimpressa, originally described as a hybrid of C. hyalinolepsis and C. lanuginosa, has been reported over a wide area and beyond the range of C. hyalinolepis. Consequently it has been accorded specific rank. Various aspects of morphology reflected in scatter diagrams as well as intermediate stomatal structure revealed through scanning electron microscopy and sectioning support the hybrid origin as originally proposed. This is further supported by field studies of natural populations where both putative parents were invariably present. Reports from beyond the range of one or both parents are the result of misidentification. The diagnostic character combination includes sparsely pubescent perigynia 4.2–6.4 mm long, with relatively short beaks, leaves 4.5–11 mm wide, and ligules 1.8–9 mm long.

scholarly journals Molecular phylogeny and morphologic data of strains of the genus Coelastrella (Chlorophyta, Scenedesmaceae) from a tropical region in North America (Yucatan Peninsula)

2017 ◽  
Vol 95 (3) ◽  
pp. 527 ◽  
Author(s):  
Katia Ancona-Canché ◽  
Silvia López-Adrián ◽  
Margarita Espinosa-Aguilar ◽  
Gloria Garduño-Solórzano ◽  
Tanit Toledano-Thompson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phenotypic Plasticity ◽  
North America ◽  
Yucatan Peninsula ◽  
Tropical Region ◽  
Its2 Rdna ◽  
Yucatán Peninsula ◽  
Good Support ◽  
Scanning Electron

<p><strong>Background: </strong>Scenedesmaceae family exhibits great morphological variability. High phenotypic plasticity and the presence of cryptic species have resulted in taxonomic re-assignments of Scenedesmaceae members.</p><p><strong>Study strains: </strong><strong>S</strong>trains CORE-1, CORE-2 and CORE-3 were characterized.</p><p><strong>Study site: </strong>Yucatan Peninsula</p><p><strong>Methods: </strong><strong>Morphological analyses were executed by optical and scanning electron microscopy. P</strong>hylogenetic relationships were examined by ITS-2 and ITS1-5.8S-ITS2 rDNA regions.<strong></strong></p><p><strong>Results:</strong> Optical and scanning electron microscopy analyses indicated spherical to ellipsoidal cells and autospore formation correspond to members of the family Scenedesmaceae, as well as observable pyrenoid starch plates. Detailed morphology analysis indicated that CORE-1 had visible granulations dispersed on the cell wall, suggesting identity with <em>Verrucodesmus verrucosus</em>. However CORE-1 did not show genetic relations with this species, and was instead clustered close to the genus <em>Coelastrella</em>. CORE-2 did not show any particular structure or ornamentation, but it did show genetic relations with <em>Coelastrella</em> with good support. CORE-3 showed meridional ribs from end to end, one of them forked and well pronounced, and orange cells in older cultures characteristic of <em>Coelastrella</em> specimens. Phylogenetic trees of ITS-2 and ITS1-5.8S-ITS2 rDNA sequences indicated with good support that all strains were related to the genus <em>Coelastrella</em> despite their morphologic differences.</p><p><strong>Conclusions: </strong>This study reports freshwater <em>Coelastrella</em> strains from a tropical region in North America (Yucatan Peninsula) for the first time. The results contribute to knowledge of <em>Coelastrella</em> species, and the fact that they do not always show structures that are useful for taxonomic assignment, probably as a result of phenotypic plasticity.</p>

scholarly journals Ecomorphological Study of Scales in Some Genera of the Viperid and Colubrid Snakes (Ophidia: Viperidae: Colubridae)

2021 ◽  
Author(s):  
morteza Akbarpour ◽  
Nasrullah Rastegar Pouyani ◽  
Behzad Fathinia ◽  
Eskandar Rastegar-pouyani
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Visible Light ◽  
Phylogenetic Relationships ◽  
Imaging System ◽  
Ecological Condition ◽  
Light Reflection ◽  
Body Parts ◽  
Snake Species ◽  
Scanning Electron

Ecomorphological studies are aimed to find out the relation between the morphology of organisms and their ecology. Many studies on reptile scale microornamentation indicate that it has important functional values. In this study microornamentation and light reflection of scales’ surface among six viperid and two colubrid snake species in relation to their habitat were examined. To compare microornamentation and light reflection analyses, skin specimens were prepared and analyzed using scanning electron microscopy and FluoVision Imaging System and spectrometer, respectively. The results showed that snake species inhabiting similar habitats had different microornamentation and vice versa. Likely the scale microstructures are more influenced by phylogenetic relationships than by the environment. In examining the scales’ reflection, different species and different body parts reflect various wavelengths of visible light, which relates to ecological condition of them.

scholarly journals Scanning Electron Microscopy: Extrapolation of 3D Data from SEM Micrographs

2015 ◽  
Vol 21 (4) ◽  
Author(s):  
Simonas KAREIVA ◽  
Algirdas SELSKIS ◽  
Feliksas IVANAUSKAS ◽  
Simas ŠAKIRZANOVAS ◽  
Aivaras KAREIVA
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sem Micrographs ◽  
3D Data ◽  
Scanning Electron

scholarly journals TAYLOR CONE–JET MODE IN THE FABRICATION OF ELECTROSPRAYED MICROSPHERES

2018 ◽  
Vol 55 (1B) ◽  
pp. 216 ◽  
Author(s):  
Viet Linh Nguyen - Vu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polymer Solution ◽  
Flow Rate ◽  
Applied Voltage ◽  
Processing Parameters ◽  
Taylor Cone ◽  
Sem Micrographs ◽  
Scanning Electron

In this study, electrospray modes were investigated to clarify their effects on the morphology and size of polycaprolactone (PCL) particles. The result indicated that electrosprayed microspheres with homogeneous and stable morphology were fabricated by using cone–jet mode and suitable electrospray processing parameters. Besides, the PCL solution was created by dissolving in dichloromethane with different concentrations such as 3.5%, 4%, 4.5% and 5%. The scanning electron microscopy (SEM) micrographs pointed that electrosprayed PCL microspheres were formed by using 4.5 % polymer solution. In addition, the reproducible and homogeneous morphology of PCL microparticles were obtained at the following set of parameters: applied voltage of 18 kV, flow rate of 1.5 mL/h and distance tip to collector of 20 cm. Moreover, at the collecting distance of 15–25 cm, the flow rate of 1.2–1.8 mL/h and applied voltage of 18 kV the cone–jet mode was generated. It was an effective electrospray mode to create stable and homogeneous microspheres.

Redescription of Placodira lobata Thorne, 1937 (Rhabditida: Cephalobidae) with a discussion of the systematic position of the genus

Nematology ◽  
2011 ◽  
Vol 13 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Irma Tandingan De Ley ◽  
Steven Nadler ◽  
Sven Boström ◽  
Cymphonee Robinson ◽  
Oleksandr Holovachov
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phylogenetic Relationships ◽  
Molecular Data ◽  
Systematic Position ◽  
Type Specimens ◽  
The Usa ◽  
Scanning Electron

AbstractA population of Placodira lobata from the USA is described using both light and scanning electron microscopy and compared with the descriptions of the type specimens of the same species. The phylogenetic relationships of the species are inferred from molecular data and places P. lobata in a clade that unites genera with mostly simple morphology of the labial region, like Cephalobus, Acrobeloides, Heterocephalobellus and Metacrobeles, but also includes species of Zeldia and Chiloplacus.

scholarly journals Assessing morphological congruence in Dinobryon species and their stomatocysts, including a newly established Dinobryon pediforme–stomatocyst connection

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jolanta Piątek ◽  
Joanna Lenarczyk ◽  
Marcin Piątek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Phylogenetic Relationships ◽  
Morphological Characters ◽  
Marine Waters ◽  
Resting Stages ◽  
The World ◽  
Scanning Electron ◽  
Sem Analyses

Abstract The chrysophyte genus Dinobryon Ehrenberg consists of 44 taxa, which occur in freshwaters, rarely marine waters, mostly in temperate regions of the world. The taxa of Dinobryon produce characteristic solitary or dendroid colonies and resting stages called stomatocysts. Only 20 Dinobryon taxa have information on produced stomatocysts and only four stomatocysts are reliably linked with vegetative stages using modern identification standards employing scanning electron microscopy (SEM) analyses. In this study, an encysted material of Dinobryon pediforme (Lemmermann) Steinecke was collected in two lakes in contrasting regions of Poland. Light microscopy (LM) and scanning electron microscopy (SEM) analyses revealed that Dinobryon pediforme produces stomatocyst #61, Piątek J. that is described here as new morphotype following the International Statospore Working Group (ISWG) guidelines. This raises to five the number of reliable links between vegetative stages of Dinobryon species and corresponding stomatocysts. Phenotypic similarities between Dinobryon species and their stomatocysts, analysed for five reliably established links, showed no relationships in size and shape between loricas and stomatocysts belonging to the same species. The morphological characters of loricas and stomatocysts mapped onto the phylogenetic tree of the five Dinobryon species revealed only little congruence between their morphology and phylogenetic relationships.

Licea aurea a new Myxomycete from the Peruvian Andes

Phytotaxa ◽  
2019 ◽  
Vol 391 (3) ◽  
pp. 218 ◽  
Author(s):  
DIANA WRIGLEY DE BASANTA ◽  
ARTURO ESTRADA-TORRES ◽  
CARLOS LADO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Moist Chamber ◽  
Peruvian Andes ◽  
Sem Micrographs ◽  
Scanning Electron

A new sessile species of myxomycete, Licea aurea is described, based on material from the Andean puna in Peru at almost 5000 m. It was isolated from moist chamber cultures of Azorella compacta litter and cultured on agar from spore to spore. It can be distinguished from other species in the genus by its small size, golden colour, dehiscence and smooth thick-walled spores with a thinner area. Life-cycle events are described and illustrated, from germination to sporulation. The morphology of the myxomycete specimens was examined using light and scanning electron microscopy, and both light and SEM micrographs of relevant details are included.

Sign in / Sign up

Export Citation Format

Share Document