Analysis of surface structures of Cladonia mitis podetia in historic and recent collections from Greenland

1995 ◽  
Vol 73 (3) ◽  
pp. 457-464 ◽  
Author(s):  
H. S. Heide-Jørgensen ◽  
I. Johnsen
Keyword(s):  
Comparative Study ◽  
Surface Structure ◽  
Key Words ◽  
Light Microscope ◽  
Shoot Tips ◽  
Surface Structures ◽  
Colour Pattern ◽  
Field Observations ◽  
Electron Microscopical ◽  
Scanning Electron

Field observations in Greenland combined with a scanning electron microscopical survey have revealed a hitherto undescribed correspondence in the distribution of a brownish colour and a crust-like surface structure formed by hyphae at exposed parts of the shoot tips of podetia of Cladonia mitis. A different brownish colour pattern is caused by fungal parasites. A comparable but less prominent colour-crust syndrome was observed on C. mitis from Denmark. The colour-crust syndrome is considered an unhealthy and damaged condition, and the light microscope reveals that areas with this syndrome mainly consist of the uncovered stereome devoid of the hyphal zone containing algal colonies. In a comparative study of podetia collected up to 105 years ago in Greenland, crust-like surface structures occur more frequently since the 1970s. Key words: Arctic lichen heath, Cladonia mitis, Greenland, podetial morphology, UV-B radiation.

scholarly journals Seed morphology and histology of some Paronychia taxa (Caryophyllaceae) from Turkey

1970 ◽  
Vol 38 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Ayse Kaplan ◽  
Hatice Çölgeçen ◽  
H Nurhan Büyükkartal
Keyword(s):  
Key Words ◽  
Seed Morphology ◽  
Epidermal Cells ◽  
Surface Structures ◽  
Dichotomous Key ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Seed morphology and histology of 12 taxa (nine species, two subspecies, one variety) of Paronychia Miller (Caryophyllaceae) by light and scanning electron microscopes revealed that seeds are laterally compressed, reniform, and hilums are linear. Testa surface structures are alveolate-scalariform, colliculate, reticulate-alveolate, rugose and ruminate. Differences in cuticle and papillae properties of epidermal cells have been observed. A dichotomous key has been developed for Paronychia agryloba Stapf, P. angorensis Chaudri, P. arabica (L.) DC. subsp. euphratica Chaudri, P. carica Chaudri, P. cataonica Chaudri, P. condensata Chaudri, P. davisii Chaudri, P. dudleyi Chaudri, P. galatica Chaudri, P. kurdica Boiss subsp. kurdica var. kurdica, P. kurdica Boiss subsp. montis-munzur Chaudri and P. mughlaei Chaudri.   Key words: Paronychia; Caryophyllaceae; Seed morphology; Seed histology; Turkey DOI: 10.3329/bjb.v38i2.5142 Bangladesh J. Bot. 38(2): 171-176, 2009 (December)  

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)

Surface structure of the urediniospores of Puccinia coronata f. sp. avenae

1970 ◽  
Vol 48 (12) ◽  
pp. 2159-2161 ◽  
Author(s):  
Michael Corlett
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Structure ◽  
Light Microscope ◽  
Puccinia Coronata ◽  
Small Ring ◽  
Scanning Electron

The surface structure of the echinulate urediniospores of Puccinia coronata f. sp. avenae race 320 was examined with the light microscope and the electron microscope. The scanning electron microscope revealed a network of ridges encircling the spines. On many urediniospores, small ring-like ridges, about 1 μ across, closely encircled the bases of the spines and sometimes were connected by fine linear ridges. On other spores, the ridges took the shape of four- to seven-sided polygons, 2–3 μ across, with triangles at their corners.

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).

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 50-51
Author(s):  
D. Johnson ◽  
P. Moriearty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Light Microscopy ◽  
Surface Structure ◽  
Extensive Study ◽  
Scanning Microscopy ◽  
Host Parasite ◽  
Conventional Electron Microscopy ◽  
Scanning Electron

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

Electron Microscopic Observation of Biological Specimens in Their Native State by Employing Cryogenic Techniques

1972 ◽  
Vol 30 ◽  
pp. 410-411 ◽  
Author(s):  
Tokio Nei ◽  
Haruo Yotsumoto ◽  
Yoichi Hasegawa ◽  
Yuji Nagasawa
Keyword(s):  
Electron Microscopic Observation ◽  
Surface Structures ◽  
Specimen Preparation ◽  
Native State ◽  
Electron Microscopic ◽  
Biological Specimen ◽  
Specimen Holder ◽  
Cold Stage ◽  
Preparation Techniques ◽  
Scanning Electron

In order to observe biological specimens in their native state, that is, still containing their water content, various methods of specimen preparation have been used, the principal two of which are the chamber method and the freeze method.Using its recently developed cold stage for installation in the pre-evacuation chamber of a scanning electron microscope, we have succeeded in directly observing a biological specimen in its frozen state without the need for such conventional specimen preparation techniques as drying and metallic vacuum evaporation. (Echlin, too, has reported on the observation of surface structures using the same freeze method.)In the experiment referred to herein, a small sliced specimen was place in the specimen holder. After it was rapidly frozen by freon cooled with liquid nitrogen, it was inserted into the cold stage of the specimen chamber.

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