scholarly journals Palyno-morphology of Hedera L. (The ivy genus, araliaceae) and their systematics implications

Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 851-865
Author(s):  
Fahimeh Fallah ◽  
Farrokh Ghahremaninejad
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Hedera Helix ◽  
Transmission Electron ◽  
Pollen Grain Size ◽  
The Relationship ◽  
Scanning Electron

The palynomorphological characteristics of 5 species belonging to Hedera of the Araliaceae family were studied in detail. These plant species were collected from various phytogeographical regions of Iran and Hungary. The palynological investigation was accomplished using Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Pollen grains of the species are reticulate, prolate, sub-prolate, tricolporate, isopolar, radially symmetrical, and monad. The largest pollen grain was in the Hedera colchica species (72.24?1.6 ?m) and the smallest pollen grain was in Hedera helix (28.63?2.1 ?m). The research carried out by the TEM showed that the species were different in terms of exine thickness, tectum thickness, foot layer thickness, the diameter and length of the Columella, the thickness and shape of the Caput, the tectum to foot layer )T/F( ratio, the absence or presence of the Endexine and the thickness of the Intine layers. The main purpose of this study was the importance of the relationship between pollen grain size and the number of chromosomes and ploidy level in Hedera species.

scholarly journals Comparison of pollen morphological structures of some taxa belonging to Asparagus L. and Fritillaria L. (Liliaceae) from Turkey

1970 ◽  
Vol 36 (2) ◽  
pp. 111-120 ◽  
Author(s):  
H Ozler ◽  
S Pehlivan
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Key Words ◽  
Transmission Electron Microscope ◽  
Light Microscope ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Exine Sculpture ◽  
Transmission Electron ◽  
Scanning Electron

Pollen grains of 20 taxa from two genera of the Liliaceae were examined and compared by LM (light microscope), SEM (scanning electron microscope) and pollens of four taxa were also examined with TEM (transmission electron microscope). Pollen grains shed as monads. They are monosulcate and ellipsoidal. Fritillaria crassifolia subsp. crassifolia Freyn & Smt. sometimes sheds the pollen as dyads. Exine is semitectate and the tectum is perforate. Columellae are simplicolumellate. Ectexine is thicker than endexine. Exine sculpture (ornamentation) is reticulate, reticulate-rugulate, rugulate and retipilate in Asparagus pollens and reticulate, suprareticulate, rugulate-reticulate and striate-reticulate in Fritillaria pollens. Sulcus extends from distal to proximal in some pollens of Asparagus and Fritillaria.   Key words: Asparagus, Fritillaria, Liliaceae, Pollen morphology DOI = 10.3329/bjb.v36i2.1498 Bangladesh J. Bot. 36(2): 111-120, 2007 (December)

scholarly journals Pollen morphology of some Allium L. (Lilliaceae) taxa in turkey

1970 ◽  
Vol 39 (1) ◽  
pp. 37-46 ◽  
Author(s):  
H Özler ◽  
S Pehlivan
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Key Words ◽  
Transmission Electron Microscope ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Exine Sculpture ◽  
Transmission Electron ◽  
Scanning Electron

Pollen grains of 16 taxa of Allium L. belonging to sections Rhizirideum G. Don ex Koch., Codonoprasum Reichb. and Allium L. were investigated using light and scanning electron microscope, and pollens of four taxa were also examined with transmission electron microscope. Pollens were monosulcate and ellipsoidal. It was observed that the sulcus extends from distal to proximal in all taxa. The exine was semitectate and the tectum was perforate. Columellae were simplicolumellate. Exine sculpture was striate-perforate, striate-rugulate-perforate and rugulate-perforate. A. albidum Fischer ex Bieb. subsp. caucasicum (Regel) Stearn, A. rupicola Boiss ex Mouterde and A. asperiflorum Miscz. were seen to have an operculum. Key words: Allium; Codonoprasum; Rhizirideum; Alliaceae; Pollen morphology; Turkey DOI: 10.3329/bjb.v39i1.5524Bangladesh J. Bot. 39(1): 37-36, 2010 (June)

scholarly journals Pollen morphology of Plantago species native to Poland and their taxonomic implications

2011 ◽  
Vol 73 (4) ◽  
pp. 315-325 ◽  
Author(s):  
Małgorzata Klimko ◽  
Krystyna Idzikowska ◽  
Mariola Truchan ◽  
Anna Kreft
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Pollen Morphology ◽  
Pore Diameter ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Prolate Spheroidal ◽  
Taxonomic Implications ◽  
Scanning Electron

Pollen grains of 9 species of the genus <em>Plantago</em> (Plantaginaceae), including 8 taxa native to Poland, were observed under a light microscope and a scanning electron microscope. Descriptions of grain sculpture are illustrated only SEM micrographs. The studied pollen grains were medium-sized or small, spherical or prolate spheroidal. Their sculpture was always verrucate with granulation. In the studied taxa, internal apertures had the form of pores. Their number ranged from (4)5-9(14). The pores were scattered on the surface of pollen grains. Identification features of individual taxa include: presence or absence of an annulus around each pore, annulus structure, ornamentation of the pollen grain and operculum, type of aperture membrane, number of internal pores, and pore diameter. We suggest that two new pollen grain types, characteristic of <em>P. intermedia</em> and <em>P. arenaria</em>, should be distinguished, and that <em>P. alpina</em> should be assigned to the <em>P. coronopus</em> type.

scholarly journals Pollen morphology of 10 taxa belonging to Prangos Lindl. and Ekimia H. Duman & M.F. Watson (Umbelliferae) from turkey and its taxonomic significance

2009 ◽  
Vol 16 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Sevil Pehlivan ◽  
Birol Baser ◽  
Evren Cabi
Keyword(s):  
Cluster Analysis ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
No Value ◽  
Quantitative Data ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Taxonomic Significance ◽  
Transmission Electron ◽  
Scanning Electron

Pollen grains of nine taxa of Prangos Lindl. and one of Ekimia H. Duman & M.F. Watson (Umbelliferae) were examined with LM (light microscope) and SEM (scanning electron microscope), and of them four with TEM (transmission electron microscope). The quantitative data were also subjected to cluster analysis. The obtained phenogram revealed that Ekimia bornmuelleri (Hub.-Mor. & Reese) H. Duman & M.F. Watson is strictly different from the taxa of Prangos regarding their quantitative pollen profile; except P. ferulacea Lindl., all taxa included in section Intactae formed a cluster together; members of section Meliocarpoides and section Prangos show a closer relationship regarding their pollen features. Exine ornamentations of Prangos and Ekimia are rugulate-striate and are of no value for identification purposes.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

Ultrastructure Research of the Gastritis from Returning Bile

1990 ◽  
Vol 48 (3) ◽  
pp. 202-203
Author(s):  
Shaopeng Hu ◽  
Jianhua Wang ◽  
Zhen Li ◽  
Huei Chen ◽  
Fei Cu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gastric Mucosa ◽  
Scanning Electron Microscope ◽  
Lamina Propria ◽  
Transmission Electron Microscope ◽  
Ultrastructural Change ◽  
Common Disease ◽  
Epithelial Surface ◽  
Transmission Electron ◽  
Scanning Electron

Gastritis from returning bile is a common disease, but the reason for the disease is not clear. As the pathologic ultrastructure research progresses, it has drawn attention to the ultrastructural change of cells in gastric mucosa by clinical workers. We observed gastric mucosa tissues of 15 patients suffering from gastritis with a transmission electron microscope (TEM) and a scanning electron microscope (SEM). It is the first report in China that fungus exists in the lamina propria of gastric mucosa tissue. The result is as follows.The gastric mucosa tissues of 15 patients suffering from gastritis were acquired by stomachoscopy. Both TEM and SEM specimens were prepared by the usual methods. Under the TEM, the epithelial surface became higher and larger. Mitochondria of the cells were swollen and cristae were disrupted. There were vacuoles in the cells. The nucleus showed disorder, heterochromatin became darker, and nucleolae could be observed.

Application of Transmission Electron Microscope and Scanning Electron Microscope in experimental tumor studies

1990 ◽  
Vol 48 (3) ◽  
pp. 306-307
Author(s):  
Gao Fengming
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Malignant Transformation ◽  
Transmission Electron Microscope ◽  
Experimental Tumor ◽  
Transmission Electron ◽  
Embryo Cells ◽  
Tumor Studies ◽  
Scanning Electron

Transmission electron microscope(TEM) and scanning electron microscope(SEM) were widely used in experimental tumor studies. They are useful for evaluation of cellular transformation in vitro, classification of histological types of tumors and treating effect of tumors. We have obtained some results as follows:1. Studies on the malignant transformation of mammalian cells in vitro. Syrian golden hamster embryo cells(SGHEC) were transformed in vitro by ThO2 and/or ore dust. In a few days after dust added into medium, some dust crystals were phagocytized. Two weeks later, malignant transformation took place. These cells were of different size, nuclear pleomorphism, numerous ribosomes, increasing of microvilli on cell surface with various length and thickness, and blebs and ruffles(Figs. 1,2). Myelomonocytic leukemic transformation of mouse embryo cells(MEC) was induced in vitro by 3H-TdR. Transformed cells were become round from fusiform. The number of mitochondria and endoplasmic reticulum was reduced, ribosomes and nucleoli increased, shape of nuclei irregular, microvilli increased, and blebs and ruffles appeared(Fig. 3).

A Working Method for Adapting the (SEM) Scanning Electron Microscope to Produce (STEM) Scanning Transmission Electron Microscope Images

2002 ◽  
Author(s):  
Edward Coyne
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Theoretical Idea ◽  
Cross Sectional ◽  
Additional Advantage ◽  
Transmission Electron ◽  
Resolution Element ◽  
Scanning Electron

Abstract This paper describes the problems encountered and solutions found to the practical objective of developing an imaging technique that would produce a more detailed analysis of IC material structures then a scanning electron microscope. To find a solution to this objective the theoretical idea of converting a standard SEM to produce a STEM image was developed. This solution would enable high magnification, material contrasting, detailed cross sectional analysis of integrated circuits with an ordinary SEM. This would provide a practical and cost effective alternative to Transmission Electron Microscopy (TEM), where the higher TEM accelerating voltages would ultimately yield a more detailed cross sectional image. An additional advantage, developed subsequent to STEM imaging was the use of EDX analysis to perform high-resolution element identification of IC cross sections. High-resolution element identification when used in conjunction with high-resolution STEM images provides an analysis technique that exceeds the capabilities of conventional SEM imaging.

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