Salvinia leaves. I. Origin and early differentiation of floating and submerged leaves

1978 ◽  
Vol 56 (16) ◽  
pp. 1982-1991 ◽  
Author(s):  
Judith G. Croxdale
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Leaf Development ◽  
Leaf Blade ◽  
Leaf Initiation ◽  
Early Differentiation ◽  
Or Groups ◽  
Apical Cells ◽  
Scanning Electron ◽  
Floating Leaf

A study of floating and submerged Salvinia leaves using light and scanning electron microscopy shows unique features in the arrangement of leaves and their growth. Leaves are produced in phyllotactic units of six; within each phyllotactic unit are two sets or groups of three leaves each. The genetic spiral of leaf initiation is not unidirectional but alternates from clockwise to counterclockwise with the production of each group of three leaves. Within each group of leaves, the sequence of primordial expansion is the reverse of their inception. Observations of floating leaf apical cells show that during development they undergo configurational changes from rectangular to hemisperical to lenticular to tetrahedral. Floating and submerged leaves diverge structurally when they are 70–90μm in length. The general course of leaf development appears to differ from previously described ferns and angiosperms in that each floating leaf blade panel is generated from the abaxial primordial surface.

Developmental comparison of leaf shape variation in three Chamaedorea species

Botany ◽  
2009 ◽  
Vol 87 (2) ◽  
pp. 210-221 ◽  
Author(s):  
Julia Nowak ◽  
Adam Nowak ◽  
Usher Posluszny
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Leaf Development ◽  
Leaf Shape ◽  
Shape Variation ◽  
Differential Growth ◽  
Scanning Electron ◽  
Palm Leaf ◽  
The Ideal

Compound palm leaf development is unique and consists of two processes. First, the primordial tissue folds through differential growth, forming plications. Second, these plications separate through an abscission-like process, forming leaflets. The second process of leaflet separation allows for the development of compound leaves. The question that this study addresses concerns the development of bifid leaves, as they do not form leaflets but only develop a cleft through an apical incision. The ideal genus to use for this study is Chamaedorea as it includes species with both pinnate and bifid leaves. Chamaedorea fragrans (Ruiz & Pav.) Mart. and Chamaedorea stolonifera H. Wendl. ex Hook. f. were chosen as the species with adult bifid leaves. Although Chamaedorea seifrizii Burret is a pinnate-leaved palm, its juvenile leaves are bifid. Scanning electron microscopy and light microscopy were used to study the development of bifid leaves. Our results indicate that neither of these bifid palms develop separation sites within the lamina, but rather the apical cleft develops through “late leaflet separation” or by an abscission-like process. In contrast, C. seifrizii juvenile leaves exhibit “early leaflet separation” when developing the apical cleft.

scholarly journals Taxonomic value of the leaf blade epidermal structure at the sectional level of Altai fescue (Festuca L.)

2020 ◽  
Vol 19 (2) ◽  
pp. 117-122
Author(s):  
E. A. Kriuchkova ◽  
M. V. Olonova ◽  
E. Z. Baiakhmetov ◽  
P. D. Gudkova
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Factor Analysis ◽  
Leaf Blade ◽  
Mixed Data ◽  
Abaxial Side ◽  
Epidermal Structure ◽  
Taxonomic Treatment ◽  
Scanning Electron

Here we present results of our study on the leaf blades epidermis using scanning electron microscopy for 16species of Festuca from Altai. The factor analysis of mixed data revealed markedly differentiated groups according to theirsectional devision. This result supports the previous phylogenetic findings in the genus, except the section Aulaxyper. Thestudy also demonstrates the importance of the abaxial side of leaves in taxonomic treatment of the species, specifically theshape of long cells and silicon bodies, as well as the location of the latter.

Étude biomathématique du nombre de glandes peltées des feuilles de Mentha ×piperita

1993 ◽  
Vol 71 (9) ◽  
pp. 1202-1211 ◽  
Author(s):  
M. Colson ◽  
R. Pupier ◽  
A. Perrin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Leaf Blade ◽  
Glandular Trichomes ◽  
Leaf Length ◽  
Mentha Piperita ◽  
Blade Surface ◽  
Precise Description ◽  
Meristematic Activity ◽  
Scanning Electron

The enumeration of peltate glands on Mentha ×piperata leaves was carried out with respect to the date of leaf initiation and the state of its development. For this purpose, observations were made using scanning electron microscopy associated with a mathematical method based on a precise description of gland dispersal on the leaf blade surface. The number of glands can thus be estimated by using only a few photographs of the foliar region located at 2/5 of the leaf length, measuring from the base. The analyses demonstrate a consistency in the number of peltate glands for a given foliar verticil, when the leaf height is equal to or greater than 10 mm. Furthermore, these analyses indicate that the number of peltate glands vary as a function of the level of the foliar verticil. This number increases progressively in verticils 1 to 10, stabilizes, and then decreases in the last verticils produced. This reduction may originate in the meristematic activity that is gradually oriented towards efflorescence. Key words: Mentha, glandular trichomes, enumeration, spatial distribution, leaves, scanning electron microscopy. [Journal translation]

scholarly journals Leaf teeth in eudicots: what can anatomy elucidate?

2020 ◽  
Vol 193 (4) ◽  
pp. 504-522
Author(s):  
Alex Batista Moreira Rios ◽  
Gisele Cristina de Oliveira Menino ◽  
Valdnéa Casagrande Dalvi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Leaf Blade ◽  
Developmental Stages ◽  
Extrafloral Nectaries ◽  
Scanning Electron

Abstract Leaf teeth are projections on the leaf blade margin. They are structurally variable, with characters that are important for taxonomy and phylogeny, but there is a paucity of information on the anatomy of these structures and little understanding of the features and their functions. Here we describe and compare the leaf tooth anatomy of 47 eudicot species. Toothed margin samples from leaves at different developmental stages were collected, fixed and studied under light and scanning electron microscopy. We identified eight leaf tooth morphotypes, six of which occurred with glands. Hydathodes were the most common glands, being found in 11 species; colleters were found in ten species and extrafloral nectaries were found in two species. Cunonioid teeth either devoid of glands or associated with hydathodes were found in Lamiales, Asterales and Apiales. Dillenioid teeth associated with hydathodes were found in Dilleniales. Spinose teeth associated with colleters were found in Aquifoliales. In rosids, we found begonioid, malvoid, theoid, urticoid and violoid teeth, which may be associated with either colleters or nectaries or lack an associated gland. For each family studied, there was only one type of association between gland and tooth, demonstrating the systematic potential of these glands in eudicots.

Epidermis and epicuticular waxes of Syagrus coronata leaflets

1995 ◽  
Vol 73 (12) ◽  
pp. 1947-1952 ◽  
Author(s):  
Raul Dodsworth Machado ◽  
Cláudia Franca Barros
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Walls ◽  
Leaf Blade ◽  
Amorphous Layer ◽  
Palm Tree ◽  
Epicuticular Waxes ◽  
Abaxial Side ◽  
Transmission Electron ◽  
Scanning Electron

The outer epidermal cell walls of the leaf blade of the licuri palm tree were studied by light microscopy, scanning electron microscopy, and transmission electron microscopy, with special attention to the epicuticular waxes. On the intensely green adaxial surface, the wax adheres in the form of a smooth, flexible, varnish-like layer. On the pruinose, dull, greenish or bluish abaxial side, the wax appears as a thin amorphous layer from which rodlets and columns protrude. Very curved rodlets, in compact rows, border each stoma, sometimes almost completely closing its aperture. Numerous pores, not resolvable with the light microscope, were detected in both cuticular membranes. Comments are presented concerning the possible functions of several configurations of epicuticular waxes. Key words: epicuticular waxes, wax micromorphology, Syagrus, licuri, epidermal wall.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

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