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 ◽  
...  

<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>

1990 ◽  
Vol 64 (4) ◽  
pp. 323-329 ◽  
Author(s):  
F. J. Kruger ◽  
C. T. Wolmarans

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.


2006 ◽  
Vol 17 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Douglas H. Ubelaker ◽  
Karen E. Stothert

AbstractThe relationship between Andean coca use and dental deposits is explored through the use of scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Elemental analyses of samples of large dental deposits from archeologically recovered skeletons from Ecuador dating between 500 B.C. and A.D. 1532 are compared with those of normal calculus deposits of individuals from North America (modern and precontact), of normal tooth structure and of samples of alkali recovered from Ecuadorian artifacts thought to have been employed in coca use. Spectral analysis revealed homogeneity among all dental samples (deposits and structure) and that they are distinct from the elemental pattern revealed in the analysis of the artifact alkalis.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
John Schenk ◽  
Carolina Granados Mendoza ◽  
Andres Eduardo Estrada-Castillón

Background: Mentzelia (Loasaceae) is primarily distributed in western North America. The genus is classified into six monophyletic sections, among which species of section Bartonia are particularly poorly understood. Questions: What species of Mentzelia section Bartonia occur in Mexico? What are the species distribution ranges and what are their defining attributes? Study species: Mentzelia section Bartonia. Methods: Field, herbarium, distribution, and scanning electron microscopy studies were conducted to assess species diversity. Seed coat microsculpture patterns were evaluated to confirm species identities and understand their distributions throughout Mexico. Results: Six species from section Bartonia were recognized, with taxa distributed into either the Chihuahuan or Sonoran deserts. Mentzelia longiloba var. pinacatensis is the only Mexican endemic. Conclusions: Although this work comprehensively addressed the species of section Bartonia in Mexico, two groups will continue to present identification challenges: the M. longiloba and M. mexicana-M. saxicola complexes. Overlapping and variable characters will continue to complicate species identification in the M. longiloba complex, while the late-season loss of primary leaves will obscure species identification between M. mexicana and M. saxicola.


2016 ◽  
Vol 61 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Joanna Lenarczyk ◽  
Konrad Wołowski

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.


Phytotaxa ◽  
2019 ◽  
Vol 423 (3) ◽  
pp. 195-205 ◽  
Author(s):  
LI YANG ◽  
QING-MIN YOU ◽  
J. P. KOCIOLEK ◽  
LI-QING WANG ◽  
WEI ZHANG

A new species, Gomphosinica selincuoensis sp. nov., is described from Lake Selincuo, North Tibet, China. This taxon is clearly different from the other species in genus Gomphosinica, with a distinctly protracted, rostrate headpole, relatively higher striae density, and distinctive areolae arrangement within the striae. Striae have areolae mostly in 3 rows, but there are places near the central portion of the valve and at footpole where there are only 2 rows of areolae per stria. Characteristics of this taxon, as observed in light and scanning electron microscopy, support its systematic placement in the genus Gomphosinica. This new species is compared with similar species in Gomphosinica from China and North America, and the biogeographic distribution of the genus is discussed.


Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 927-936 ◽  
Author(s):  
Makeli Garibotti Lusa ◽  
Maria Regina Torres Boeger ◽  
Maria Cecília de Chiara Moço ◽  
Cleusa Bona

Abstract Aquatic macrophytes show great phenotypic plasticity and are able to occupy environments with different physicochemical conditions. The present study aimed to characterize morphology and anatomical structure of the pondweed, Potamogeton polygonus Cham. & Schltdl., and to identify adaptive modifications of the plant in lotic and lentic environments. Sampling was carried out in Palmas and General Carneiro, Paraná state, southern Brazil. Ten individuals from each locality were collected. Morpho-anatomical characteristics of the roots, stems and leaves were measured. The anatomical structure was analyzed with light microscopy and scanning electron microscopy. Significant morphological and anatomical adaptive differences were observed between plants of the two environments.


2000 ◽  
Vol 77 (11) ◽  
pp. 1662-1668 ◽  
Author(s):  
Daniel F Brunton ◽  
Donald M Britton

A new interspecific Isoetes hybrid, I. echinospora Dur. × I. tuckermanii A. Br., is described from northeastern North America by means of cytology and the scanning electron microscopy of spores. Isoetes ×echtuckerii D.F. Brunton and D.M. Britton, hyb. nov., is the name proposed for this taxon. It is triploid, produces only aborted, sterile spores and has spore ornamentation intermediate between that of its putative parents. Populations have been identified in eastern Canada and the adjacent United States of America growing in association with one or both parents in shallow, fresh water along oligotrophic lake and river shores. Key words: Isoetes ×echtuckerii, interspecific hybrid, Canada, United States of America.


HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 259C-259 ◽  
Author(s):  
David T. Handley ◽  
James E. Pollard

The tarnished plant bug (Lvgus lineolaris) is a serious pest of strawberries in North America, causing a severe malformation of the receptacle known as “apical seediness” or “buttoning”. Light and scanning electron microscopy were used to assess tarnished plant bug feeding on strawberries and to determine the nature of the injury. During early fruit development stages (anthesis to petal fall) the primary feeding sites were developing achenes. Feeding sites on more developed fruit changed to receptacle tissue, usually close to an achene. The “buttoning” malformation of strawberries associated with tarnished plant bug is most likely a result of the destruction of achenes during early fruit development stages. Feeding on receptacle tissue later in fruit development causes more localized damage, such as creases and indentations.


Zootaxa ◽  
2009 ◽  
Vol 1984 (1) ◽  
pp. 57-60
Author(s):  
FEDOR ČIAMPOR JR. ◽  
ZUZANA ČIAMPOROVÁ-ZAŤOVIČOVÁ ◽  
JÁN KODADA

The mature larva of Oulimnius echinatus Berthélemy is described for the first time, based on material from Mallorca (Spain). Morphologically the larva of O. echinatus resembles those of O. jaechi Hernando, Ribera & Aguilera and O. fuscipes (Reiche, 1879), from which it differs in the distinctly denser dorsal granulation, the less prominent setiferous tubercle on posterior angles of tergites and the absence of mesal setiferous tubercle on tergites and ventrites. We used for the first time scanning electron microscopy to describe the morphology of an Oulimnius larva. The genus Oulimnius Gozis occurs in Europe, North Africa and North America (Kodada & Jäch 2005; Jäch et al. 2006). To date, 16 species and subspecies have been described, although the systematic position of the two American species within the genus is open to question.


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