scholarly journals Morphology, anatomy and leaf ultrastructure of Froelichia tomentosa (Mart.) Moq. (Amaranthaceae) - a critically endangered species in Brazil

2021 ◽  
Vol 43 ◽  
pp. e26
Author(s):  
Aline Viana ◽  
Elisete Maria de Freitas ◽  
Shirley Martins Silva
Keyword(s):  
Electron Microscopy ◽  
Leaf Blade ◽  
Leaf Ultrastructure ◽  
Abaxial Surface ◽  
Conservation Units ◽  
Critically Endangered Species ◽  
Kranz Anatomy ◽  
Transmission Electron ◽  
Pampa Biome ◽  
Different Populations

In Brazil, Froelichia tomentosa (Mart.) Moq. has records of occurrence in Rio Grande do Sul (RS) and Bahia, however, in the former there are indications that its populations are extinct. In the RS, the records are restricted to the region of sandy- fields. In this region, biodiversity has been threatened by advances in agriculture and forestry that intensified in the sandy patch process. Therefore, this work aimed to describe the morphoanatomy and ultrastructure of the leaf blade in Froelichia tomentosa, seeking to correlate leaf characteristics to the environmental conditions. Individuals from different populations in the sand- fields (Pampa biome) were sampled. Leaf blade analyzes were performed by scanning electron microscopy (SEM), transmission electron microscopy (MET) and optical microscopy (MO). The following anatomical features were verified: epidermis with trichomes and stomata in the adaxial and abaxial surface, compact mesophyll, aquiferous hypodermis, Kranz anatomy, and numerous plastoglobules and peroxisomes. The presence of these characters may be related to the adaptation of this species to environment. In addition, we highlight the necessity to create conservation units in the sand-fields region, in order to preserve species as well as that of the present study.

Collenchyma in Panicum maximum (Poaceae): localisation and possible role

2003 ◽  
Vol 51 (1) ◽  
pp. 69 ◽  
Author(s):  
Elder A. S. Paiva ◽  
Sílvia R. Machado
Keyword(s):  
Electron Microscopy ◽  
Leaf Blade ◽  
Sudden Change ◽  
Panicum Maximum ◽  
Vascular Bundles ◽  
Serial Sections ◽  
Adaxial Side ◽  
Transition Area ◽  
Transmission Electron ◽  
Phases Of Development

This work relates the occurrence and distribution of collenchyma in Panicum maximum Jacq. P.�maximum leaves were collected at different phases of development and sampled from both the base of the sheath and from the sheath–leaf blade transition area. For the stems, the study was made by using hand-cut sections of the internodal base. In the leaves, analyses of serial sections showed, at the base and sheath–leaf blade transition area, a sudden change of tissue at vascular bundle. The vascular bundles are surrounded by sclerenchyma, both in the sheath and the leaf blade, as well as by fibrous threads that occur on the adaxial side of the central bundles. However, at the base of the sheath and at the sheath–leaf blade transition area, sclerenchyma was substituted for collenchyma. In the stem, the substitution of sclerenchyma associated with vascular bundles for collenchyma occurs at the base of the internode, in the pulvinus region. The analyses from transmission electron microscopy showed the presence of lamellated cell wall and active protoplast in collenchyma cells.

Effects Of Varying Salinity On Leaf Ultrastructure Of Potamogeton Pectinatus L

1999 ◽  
Vol 5 (S2) ◽  
pp. 1256-1257
Author(s):  
A.D. Barnabas ◽  
P. Bunsi ◽  
Y. Naidoo ◽  
W.J. Przybylowicz ◽  
J. Mesjasz-Przybylowicz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Salinity ◽  
Ultrastructural Changes ◽  
Potamogeton Pectinatus ◽  
Leaf Epidermis ◽  
Leaf Ultrastructure ◽  
Low Salinity ◽  
Transmission Electron ◽  
Standard Procedures

Potamogeton pectinatus is a submerged halophyte which occurs in waters of low salinity (5% to 10%). Its upper salinity tolerance has been reported to be 19%. Reasons why P.pectinatus is unable to tolerate salinities in excess of 19%is important to our understanding of its biology. In the present study, leaf ultrastructure of plants growing at low salinity was compared with plants growing at high salinity in order to assess the effects of different salinities on the ultrastructure. Attention was focussed on ultrastructural changes occurring in the leaf epidermis, the main photosynthetic tissue.Plants were grown in seawater at two salinities : 5%(low salinity) and 20% (high salinity). Pieces of mature leaf blades from both treatments were harvested and prepared for Transmission Electron Microscopy (TEM) following standard procedures. The overall distribution and concentration of chlorine (CI) in the leaves was ascertained since this element is the most abundant anion in seawater and is important in considerations of salt tolerance in submerged halophytes.

Morphology of Foliar Trichomes of the Chinese Cork OakQuercus variabilisby Electron Microscopy and Three-Dimensional Surface Profiling

2011 ◽  
Vol 17 (3) ◽  
pp. 461-468 ◽  
Author(s):  
Ki Woo Kim ◽  
Do-Hyun Cho ◽  
Pan-Gi Kim
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Abaxial Surface ◽  
Single Row ◽  
Adaxial Surface ◽  
Surface Profiling ◽  
Transmission Electron ◽  
Ultrastructural Characterization ◽  
Disturbance Factor ◽  
Dimensional Surface

AbstractMorphology of foliar trichomes was analyzed inQuercus variabilisby electron microscopy and three-dimensional surface profiling. Leaves from suppressed or dominant sprouts of the oak species were collected after a forest fire to unravel the effects of the disturbance factor on sprouting of the oak species. Scanning electron microscopy revealed two types of trichomes depending on the leaf surface. The trichomes on the adaxial surface were branched and constricted, and possessed a single row of thin-walled cells with a collapsed morphology (glandular branched uniseriate trichomes). Meanwhile, the trichomes on the abaxial surface were star-shaped, unfused with each other, and had 6 to 10 rays (nonglandular simple stellate trichomes). An apparent proliferation of trichomes was evident on the adaxial surface of the dominant sprouts. Uniseriate trichomes could be discernable as an elevation from the surface by white light scanning interferometry. By transmission electron microscopy, thin and convoluted cell wall, degenerated cytoplasm, and a single row of cells were characteristic of the trichomes on the adaxial surface. The thick cell walls of the mature trichomes on the abaxial surface represented the nonglandular nature. This is the first report on the morphological and ultrastructural characterization of foliar trichomes of the oak species.

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.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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).

Transmission Electron Microscopy Studies of Pore Cells in Limax Maximus

1977 ◽  
Vol 35 ◽  
pp. 656-657
Author(s):  
B. S. Beltz
Keyword(s):  
Electron Microscopy ◽  
Cell Periphery ◽  
Salivary Duct ◽  
Terrestrial Mollusc ◽  
Buccal Ganglia ◽  
Transmission Electron ◽  
Pore Cells ◽  
Gland Tissue ◽  
Storage Area ◽  
Limax Maximus

The cells which are described in this study surround the salivary nerve of the terrestrial mollusc, Limax maximus. The salivary system of Limax consists of bilateral glands, ducts, and nerves. The salivary nerves originate at the buccal ganglia, which are situated on the posterior face of the buccal mass, and run along the salivary duct to the gland. The salivary nerve branches several times near the gland, and eventually sends processes into the gland.The pore cells begin to appear at the first large branch point of the salivary nerve, near the gland (Figure 1). They follow the nerve distally and eventually accompany the nerve branches into the gland tissue. The cells are 20-50 microns in diameter and contain very small nuclei (1-5 microns) (Figure 2).The cytoplasm of the pore cells is segregated into a storage area of glycogen and an organelle region located in a band around the cell periphery (Figure 3).

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