Spore morphology and wall ultrastructure of Lomariocycas (Blechnaceae) species from America

2019 ◽  
Vol 269 ◽  
pp. 55-63 ◽  
Author(s):  
J.P. Ramos Giacosa
Keyword(s):  
Spore Morphology ◽  
Wall Ultrastructure

scholarly journals Palynological analysis of Dennstaedtiaceae taxa from the Paranaense Phytogeographic Province that produce Trilete spores II: Microlepia speluncae and Pteridium arachnoideum

2016 ◽  
Vol 88 (2) ◽  
pp. 877-890 ◽  
Author(s):  
Agustina Yañez ◽  
Gonzalo J. Marquez ◽  
Marta A. Morbelli
Keyword(s):  
Comparative Analysis ◽  
Three Dimensional ◽  
Middle Layer ◽  
The Other ◽  
Spore Morphology ◽  
Central Channel ◽  
Palynological Analysis ◽  
Dimensional Network ◽  
The Family ◽  
Wall Ultrastructure

The spore morphology and wall ultrastructure of Microlepia speluncae and Pteridium arachnoideum from the Paranaense Province were analyzed with LM, SEM and TEM and a comparative analysis was carried out. In both species the spores are covered by a three-dimensional network of threads branched and fused, tangentially arranged to the surface, and some free-end threads are also seen. The species were differentiated by morphology and the frequency of threads fusion and the networks distribution on the surface of the spores. In both species the exospore is two-layered in section, both layers are traversed by single or branched channels. The perispore is three-layered in section: the inner layer is adhered to the exospore, the middle layer is formed of a three-dimensional network of threads and the outer layer is discontinuous. The perispore ultrastructure of Microlepia speluncae was interpreted as formed of helical subunits displayed around a central channel. The spore morphology and perispore ultrastructure allow differentiating Microlepia from Pteridium but also to the other Dennstaedtiaceae genera that grow in the Paranaense Province. The results obtained allow establishing relationships that let us recognize different groups and gave a new reference to get a better knowledge of the family.

Spore morphology and wall ultrastructure of Hymenophyllaceae Link (Pteridophyta) from north-west Argentina

Grana ◽  
2010 ◽  
Vol 49 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Marta A. Morbelli ◽  
Maria Raquel Piñeiro ◽  
Gabriela E. Giudice
Keyword(s):  
Spore Morphology ◽  
North West ◽  
Wall Ultrastructure

Spore morphology and wall ultrastructure of Blechnum L. species from North West Argentina

2009 ◽  
Vol 156 (1-2) ◽  
pp. 185-197 ◽  
Author(s):  
J.P. Ramos Giacosa ◽  
M.A. Morbelli ◽  
G.E. Giudice
Keyword(s):  
Spore Morphology ◽  
North West ◽  
Wall Ultrastructure

scholarly journals Palynological analysis of Sphaeropteris gardneri (Cyatheaceae, Pteridophyta)

2010 ◽  
Vol 82 (2) ◽  
pp. 361-367 ◽  
Author(s):  
Gonzalo J. Marquez ◽  
Marta A. Morbelli ◽  
Gabriela E. Giudice
Keyword(s):  
Outer Layer ◽  
Spore Morphology ◽  
Palynological Analysis ◽  
Radial Orientation ◽  
Sem And Tem ◽  
Wall Ultrastructure ◽  
The One

The spore morphology and wall ultrastructure of Sphaeropteris gardneri (Hook.) R.M. Tryon from Brazil were analyzed with LM, SEM and TEM. The spores are trilete with an ornamentation formed of short low ridges with spines in their margins. The exospore is 2.5μm thick, two- layered in section and single or branched channels are present. The perispore is 1.2μm thick and two-layered. The inner layer has three strata: the inner stratum is formed of a network of branched and fused threads, the middle stratum has threads with a radial orientation and in the outer stratum thin, dark fibres are immersed in a less dense contrasted matrix. The outer layer of the perispore is the one that forms the echinate-ridges and is constituted of threads arranged in a compact way. Globules of different sizes are observed on the surface. The differences found in the perispore ornamentation and ultrastructure in Alsophila, which was previously studied, and those of Sphaeropteris, show a tendency to wall complexity.

Spore morphology and wall ultrastructure of Trachypteris species (Pteridaceae)

2011 ◽  
Vol 294 (3-4) ◽  
pp. 227-237 ◽  
Author(s):  
Juan P. Ramos Giacosa ◽  
Marta A. Morbelli ◽  
Gabriela E. Giudice
Keyword(s):  
Spore Morphology ◽  
Wall Ultrastructure

Spore morphology and wall ultrastructure of Lycopodiaceae from northwest Argentina

2016 ◽  
Vol 225 ◽  
pp. 84-94 ◽  
Author(s):  
J.P. Ramos Giacosa ◽  
M.A. Morbelli ◽  
G.E. Giudice ◽  
D.A. Gorrer
Keyword(s):  
Spore Morphology ◽  
Northwest Argentina ◽  
Wall Ultrastructure

Cell Wall Ultrastructure in Three Strains of a Cariogenic Streptococcus

1971 ◽  
Vol 29 ◽  
pp. 338-339
Author(s):  
M. J. Kramer ◽  
Alan L. Coykendall
Keyword(s):  
Cell Wall ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Genetic Heterogeneity ◽  
Morphological Characteristics ◽  
Electron Microscopic ◽  
Dna Reassociation ◽  
Wall Ultrastructure

During the almost 50 years since Streptococcus mutans was first suggested as a factor in the etiology of dental caries, a multitude of studies have confirmed the cariogenic potential of this organism. Streptococci have been isolated from human and animal caries on numerous occasions and, with few exceptions, they are not typable by the Lancefield technique but are relatively homogeneous in their biochemical reactions. An analysis of the guanine-cytosine (G-C) composition of the DNA from strains K-1-R, NCTC 10449, and FA-1 by one of us (ALC) revealed significant differences and DNA-DNA reassociation experiments indicated that genetic heterogeneity existed among the three strains. The present electron microscopic study had as its objective the elucidation of any distinguishing morphological characteristics which might further characterize the respective strains.

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