Circumscription of the genus Medicago (Leguminosae) by seed characters

1990 ◽  
Vol 68 (3) ◽  
pp. 613-629 ◽  
Author(s):  
Ernest Small ◽  
Brenda Brookes ◽  
Per Lassen
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Wide Sense ◽  
Seed Surface ◽  
Light Line ◽  
Seed Characters ◽  
Close Relatives ◽  
Scanning Electron

Delimitation of Medicago from its close relatives in tribe Trifolieae subtribe Trigonellinae remains controversial. Scanning electron microscope studies of the seed surface of Medicago, Trigonella, and Melilotus showed consistent differences between Medicago and the other two genera. Smooth and rough seeds occur in all three genera, the rough seeds proving taxonomically useful. The roughness of Medicago seeds is due to rugose surface bumps (usually wrinkled, always with rounded sides), except in the monotypic section Orbiculares. The roughness of seeds of Trigonella, Melilotus, and Medicago section Orbiculares is due to tuberculate surface bumps. The structure of the Malpighian layer shows completely parallel taxonomic differences. The Malpighian cells are traversed by the light line, and the length of the portion of the cell above the light line (a) and that below the light line (b) distinguishes smooth, rugose, and tuberculate seeds. In smooth seeds (of Medicago, Melilotus, and Trigonella), a and b are constant. In rugose seeds (in Medicago only), a is constant while b is greater under the testa bumps, varying with the height of the portion of the bump occupied. In tuberculate seeds (in Medicago section Orbiculares, and in Trigonella and Melilotus), b is constant while a is greater under the testa bumps. These studies confirm the appropriateness of circumscribing Medicago in a wide sense, except for the inclusion of Medicago section Orbiculares.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

scholarly journals Contribution to the systematic knowledge of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey

2020 ◽  
Vol 27 (1) ◽  
pp. 27-35
Author(s):  
Emrah Şirin ◽  
Mehmet Cengiz Karaismailoğlu
Keyword(s):  
Electron Microscope ◽  
Chromosome Number ◽  
Scanning Electron Microscope ◽  
Geographical Distribution ◽  
Anatomical Structures ◽  
Seed Surface ◽  
Cytological Data ◽  
Surface Ornamentation ◽  
Systematic Knowledge ◽  
Scanning Electron

The aim of this study was to document the taxonomical, morphological, anatomical, palynological and cytological characters, and geographical distribution of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey. The description of the taxon was revised as a consequence of comprehensive assessments of many specimens. The surface pictures belonging to seed and pollen of the taxon were obtained by Scanning Electron Microscope. The seed surface ornamentation was rugose. The pollen was radially and isopolar and prolate in forms, with polar axes of 19.52 ± 0.29 μm and equatorial axes of 13.04 ± 0.22 μm, with oval outlines in the equatorial axes, and elliptical in the polar axes. They were three–colpate and colpus sizes varied between 12.98 μm and 13.29 μm in length, and between 1.33 and 2.09 μm in width. Also, the anatomical structures of the root, stem and leaf of species were studied. In cytological studies, the chromosome number of species was found as 2n = 16 (x =8). This was the first work including taxonomical, morphological (macro and micro), anatomical and cytological data of endemic Aubrieta pinardii. Bangladesh J.Plant Taxon. 27(1): 27-35, 2020 (June)

Synthesis of ZrO2 Nanotubes by Anodization of Zr Foil

2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno
Keyword(s):  
Aqueous Solution ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Preparation ◽  
The Other ◽  
Preparation Methods ◽  
X Ray ◽  
Anodization Time ◽  
Other Hand ◽  
Scanning Electron

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.

The study on antennal sensilla of eight Acrididae species  (Orthoptera: Acridoidea) in Northeast China

Zootaxa ◽  
2007 ◽  
Vol 1544 (1) ◽  
pp. 59-68 ◽  
Author(s):  
NA LI ◽  
BING-ZHONG REN ◽  
MIAO LIU
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Northeast China ◽  
The Other ◽  
Antennal Sensilla ◽  
Male And Female ◽  
Trichoid Sensilla ◽  
Basiconic Sensilla ◽  
Scanning Electron

The types, numbers and distributions of antennal sensilla were studied in both male and female adults of eight Acrididae species in Northeast China using scanning electron microscope (SEM). Totally, there were thirteen types of sensilla found on the antennae. They were identified as trichoid sensilla (I, II), chaetic sensilla (I, II), basiconic sensilla (I, II, III, IV, V), cavity sensilla, coeloconic sensilla, boehm's bristles and paddle-shaped sensilla. The types of antennal sensilla in each Acrididae species ranged from nine to twelve. Each of the species had the same types of antennal sensilla in male and female, and males had more abundant basiconic sensilla, chaetic sensilla, coeloconic sensilla, cavity sensilla than females. Acrida cinerca had the largest total numbers of sensilla, and Euthystria lueifemora had the fewest. Boehm's bristles had a concentration in the base of the pedicel. Paddle-shaped sensilla had a concentration in the base of the scape. There were significant differences in the distribution of the other eleven types of sensilla.

A new species of Tabularia (Kützing) Williams & Round from Poyang Lake, Jiangxi Province, China, with a cladistic analysis of the genus and their relatives

Phytotaxa ◽  
2018 ◽  
Vol 373 (3) ◽  
pp. 169 ◽  
Author(s):  
YUE CAO ◽  
PAN YU ◽  
QINGMIN YOU ◽  
REX L. LOWE ◽  
DAVID M. WILLIAMS ◽  
...  
Keyword(s):  
Electron Microscope ◽  
New Species ◽  
Scanning Electron Microscope ◽  
Poyang Lake ◽  
Cladistic Analysis ◽  
The Other ◽  
Jiangxi Province ◽  
A New Species ◽  
Scanning Electron

A new species of Tabularia, Tabularia sinensis, is described from the inland Poyang Lake (Jiangxi Province), the largest lake in China. The description is based on light and scanning electron microscope observations of valve and girdle elements. Given the diversity of forms in the genus, the relationships and status of the genus was investigated in the context of the other known species in the genus and to ascertain if Tabularia, as originally circumscribed, remains monophyletic.

Pattern of the Seed Surface of Goodenia and Related Genera

1980 ◽  
Vol 28 (1) ◽  
pp. 123 ◽  
Author(s):  
RC Carolin
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Evolutionary Trends ◽  
Seed Surface ◽  
Taxonomic Description ◽  
Surface Patterns ◽  
Scanning Electron

The surface patterns of seeds of 88 species of Goodenia and related genera were examined under scanning electron microscope and light microscope. With use of sections as well, the patterns were resolved into six attributes of which each was present in one of at least two states. Certain combinations of states of attributes are used to define terms which are used for purposes of taxonomic description. Six such terms are defined in this way. The results indicate that previous taxonomic arrangements are unsatisfactory. A brief commentary on possible evolutionary trends is provided and the relationships of the various satellite genera to Goodenia are discussed.

Micro-Structural Studies of Leached SON-68-Type Glasses

2001 ◽  
Author(s):  
N. Ollier ◽  
G. Panczer ◽  
B. Champagnon ◽  
P. Jollivet
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Rare Earth Element ◽  
Earth Element ◽  
The Other ◽  
Structural Studies ◽  
Microscopic Features ◽  
Precipitated Phases ◽  
Scanning Electron

Abstract Two types of borosilicate leached SON68-type glasses were studied, one doped with uranium and the other with rare-earth element (Nd, Eu). Photoluminescence and cathodoluminescence properties of U doped samples have been correlated to microscopic features of the corroded glass. Nuclear analysis, Electronic Microprobe and Scanning Electron Microscope investigations revealed the heterogeneous composition of the gels with differentiated phases. Enriched U phases (crystallised or not) and phosphorus precipitated phases in rare earth gel have been detected.

A redescription of Metopa species (Amphipoda, Stenothoidae) based on the type material. 1. Zoological Museum, Copenhagen (ZMUC)

Zootaxa ◽  
2009 ◽  
Vol 2093 (1) ◽  
pp. 1-36 ◽  
Author(s):  
ANNE HELENE S. TANDBERG ◽  
WIM VADER
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Taxonomic Position ◽  
Type Material ◽  
Zoological Museum ◽  
Type Specimens ◽  
Line Drawings ◽  
New Material ◽  
Scanning Electron

This paper presents redescriptions of amphipods in the genus Metopa (Stenothoidae) in the type-collections of the Zoological Museum of Copenhagen. For Metopa clypeata and M. abyssalis we redescribe the type-specimens, for M. glacialis and M. groenlandica the redescriptions are based on new material and checked against the type-specimens. For all except M. abyssalis a combination of new line drawings and scanning electron microscope (SEM) pictures is provided, for M. abyssalis, line drawings only. A summary of the other species having earlier been designed to Metopa in the Copenhagen collections is given, with a list of their present taxonomic position.

Choosing a Scanning Electron Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 896-897
Author(s):  
W. A. Lambe ◽  
P.M. Brady
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Selection Process ◽  
The Other ◽  
Hard Data ◽  
Methodical Approach ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
First Time ◽  
Scanning Electron

The variety of instrumentation available to the researcher today can be overwhelming and confusing. Scanning Electron Microscopes (“SEM's) are no exception, and choosing one can often serve as an exercise in dealing with complexity. First time purchasers are most at risk, being subject to a barrage of information that attempts to sway the purchaser in one direction or the other. As a result, one can sometimes be drawn to the details of the latest “high end” performance parameter, while overlooking the basics. At its worst, the selection process can degrade to one of vague guesswork with little hard data to serve as a compass.By applying a methodical approach to define your individual requirements, carefully designed tests of actual instruments, and discussions with your collaborators, potential and experienced users, one can begin to ensure a successful selection process.

Additional taxonomic studies on Avena fatuoids: some morphological attributes seen using the scanning electron microscope

1971 ◽  
Vol 49 (5) ◽  
pp. 647-649 ◽  
Author(s):  
Bernard R. Baum
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Avena Fatua ◽  
The Other ◽  
Electron Microscopic ◽  
Morphological Attributes ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Taxonomic Studies ◽  
Scanning Electron

This paper describes and evaluates the results of a scanning electron microscopic study of the sculpture of the surfaces of caryopses, glumes, lemmas, awn columns, and awn subules of Avena fatua, normal cultivated oats (A. sativa), fatuoids, and F1 hybrids A. fatua × sativa. Only qualitative differences were sought, and none were detected in the glumes and on the caryopses. The prickles on the lemmas, on the awn columns, and on the awn subules all appear in two character states. In the case of the lemmas one state is found in the normal cultivated oats, fatuoids, and F1 hybrids, and the other in A. fatua. On the other hand in the awn subules one state is found in the normal cultivated oats and the other in fatuoids, F1 hybrids, and A. fatua, while in the awn columns one state occurs in cultivated oats and the other in A. fatua, but in the F1 hybrids and fatuoids both states occur. These findings provide taxonomic evidence additional to that described earlier based on lodicules coupled with traditional characters.

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