scholarly journals Ontogenesis of the Potamogeton flower and fruitlet in SEM research

2014 ◽  
Vol 71 (2) ◽  
pp. 93-100
Author(s):  
Cezary Toma
Keyword(s):  
Morphological Development ◽  
Floral Primordia ◽  
Morphological Differences ◽  
Individual Rate

The morphological development of fruitlets representing the four sections of the genus <em>Potamogeton</em> was investigated. Evident morphological differences in the course of the development of fruitlets between the species studied were found. They concern: a) size, shape and outline of carpels and fruitlets, b) individual rate of fruitlet development, c) angle arrangement of the fruitlets, and d) structure of the basal and the apical parts of the fruitlets. Acropetal initiating of the floral primordia was found, as well as the fact that the fruitlet surfaces are very variable and thus useless for taxonomical purposes.

Morphological development, distribution and ecology of the arctic oribatid mite Hermannia scabra (Acari: Oribatida: Hermanniidae) and synonymy of Hermannia gigantea

Zootaxa ◽  
2019 ◽  
Vol 4717 (1) ◽  
pp. 104-136
Author(s):  
SERGEY G. ERMILOV ◽  
OLGA L. MAKAROVA ◽  
MIKHAIL S. BIZIN
Keyword(s):  
Differential Diagnosis ◽  
Morphological Traits ◽  
Oribatid Mite ◽  
West Siberia ◽  
The Arctic ◽  
Morphological Development ◽  
Distribution And Ecology ◽  
Morphological Differences ◽  
Northern Species ◽  
Middle Siberia

The topotypes (adult and juvenile instars) of the arctic oribatid mite Hermannia scabra (L. Koch, 1879) (Oribatida, Hermanniidae) from Vaygach Island (easternmost arctic Europe) were investigated and compared with those of Hermannia gigantea Sitnikova, 1975 collected from southwest Taymyr Peninsula, northern Middle Siberia, resulting in the following new taxonomic proposal: Hermannia scabra (L. Koch, 1879) (= Hermannia gigantea Sitnikova, 1975, syn. nov.). The morphology of its all instars is described and illustrated in detail on the base of specimens collected from the northern West Siberia (Shokalsky Island). The main morphological traits are summarized. Two northern species of Hermannia with granulate notogaster, namely H. scabra and H. nodosa Michael, 1988, were regularly mixed up in the literature. Their differential diagnosis is provided after elaboration of spacious materials. The morphological differences of juvenile instars of five species of Hermannia (H. gibba (C.L. Koch, 1839), H. jesti Travé, 1977, H. nodosa, H. reticulata Thörell, 1871, and H. scabra) are given. The biotopic preferences of arctic members of Hermannia are briefly observed. 

Development of sexual characters in the cave shrimp genus Troglocaris (Crustacea: Decapoda: Atyidae) and their applicability in taxonomy

Zootaxa ◽  
2010 ◽  
Vol 2488 (1) ◽  
pp. 1 ◽  
Author(s):  
JURE JUGOVIC ◽  
SIMONA PREVORČNIK ◽  
BORIS SKET
Keyword(s):  
Principal Component Analysis ◽  
Function Analysis ◽  
Principal Component ◽  
Morphological Development ◽  
Closely Related Species ◽  
The Past ◽  
Morphological Studies ◽  
Males And Females ◽  
Morphological Differences ◽  
Age And Sex

In most Atyidae species, male pleopods I–II are specifically shaped in adults. In some species, the same holds true for male pereopods III–V. Due to the age and sex-dependent morphology of these structures, which are presumably used during mating, certain taxonomic mistakes in species diagnoses and identifications have occurred in the past. We studied the morphological development of these appendages in males of the cave shrimp Troglocaris (Troglocaris) planinensis Birštejn, 1948 (= W-Slo phylogroup by Zakšek et al. 2009). In addition, we examined the ontogeny of these structures in males and females from other phylogroups of the subgenus Troglocaris Dormitzer, as well as in the subgenera Spelaeocaris Matjašič, 1956 and Troglocaridella Babić, 1922. Multivariate Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA) on males from the subgenus Troglocaris, confirmed the division of late ontogenetic development into sequential phases. The results indicate that in atyids (1) only mature specimens should be considered when searching for reliable morphological differences between closely related species, (2) pleopods and pereopods show diverse differentiation between taxa, preventing the reliable ascertainment of maturity at all times, (3) body size is often not a reliable indicator of maturity, (4) generally, only very rich samples ensure the presence of the fully mature males that are needed for adequate morphological studies.

Selective Action of Trifluralin for Control of Green Foxtail in Wheat

Weed Science ◽  
1970 ◽  
Vol 18 (6) ◽  
pp. 754-759 ◽  
Author(s):  
A. Rahman ◽  
R. Ashford
Keyword(s):  
Shoot Growth ◽  
Surface Soil ◽  
Early Stage ◽  
Soil Surface ◽  
Morphological Development ◽  
Untreated Soil ◽  
Selective Action ◽  
Selective Control ◽  
Green Foxtail ◽  
Morphological Differences

The selective action of α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) for the control of green foxtail(Setaria viridis(L.) Beauv.) in wheat(Triticum aestivumL.) was studied. Seedlings of both species, especially in the early stage of growth, were particularly susceptible to herbicide applied in the region of the coleoptile node. Selective control with trifluralin was possible, however, because of the morphological differences between the seedlings of the two species. Thus, the sensitive coleoptilar node area of green foxtail was located at a depth of less than 1 cm from the soil surface regardless of planting depth. The coleoptile node of wheat remained closely associated with the caryopsis. When a protective band of untreated soil was used to separate the caryopses from a 5-cm band of surface soil containing 1.12 ppmw of trifluralin, the shoot growth of wheat was normal. Much lower rates of trifluralin effectively controlled green foxtail, as surface or subsurface placement of a 1.3-cm layer of soil containing 1.12 ppmw of chemical above the foxtail caryopses completely inhibited shoot development. In addition to the differences in morphological development between the two species, the fact that green foxtail was considerably more susceptible to trifluralin than wheat was considered as an important factor contributing to the selective control.

scholarly journals Pollen Ontogeny Comparison of Natural Male-Fertile Diploid and Male-Sterile Triploid Lilium lancifolium in Korea

2015 ◽  
Vol 140 (6) ◽  
pp. 550-561 ◽  
Author(s):  
Gyeong Ran Do ◽  
Ju Hee Rhee ◽  
Wan Soon Kim ◽  
Yun Im Kang ◽  
In Myung Choi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Male Sterility ◽  
Pollen Grains ◽  
Comparative Investigation ◽  
Morphological Development ◽  
Male Sterile ◽  
Complex Species ◽  
Pollen Ontogeny ◽  
Lilium Lancifolium ◽  
Morphological Differences

Lilium lancifolium (syn. L. tigrinum) is the only polyploidy-complex species involving both diploid (2n = 2x = 24) and triploid (2n = 3x = 36) plants in the genus. The origin of natural triploid remains a mystery and research has been limited mainly to chromosomal studies that have overlooked research on pollen ontogeny. By spatiotemporal comparison of the development and morphology of diploid and triploid pollen grains, we study the correlations between pollen fertility and morphological development in diploid and triploid plants and propose the necessity and importance of further research on natural polyploid-ontogenetic diversity. In this comparative investigation, we used various microscopy techniques including histological analyses, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The main morphological differences between triploid and diploid pollen grains started with abnormal tetrad formation of triploid, followed by inadequate amylogenesis and amylolysis in young microspores, and finished with the formation of an abnormal structure of pollen surface layers in maturing pollen grains, which finally resulted in pollen grain unfolding and male sterility. From observing the series of morphological events that induced male-sterile pathway in natural triploid pollens, this study showed a variety of correlations between pollen development and fertility, which differed from male sterility resulting from gene mutation, indicating that there exists greater variability in pollen male-sterile ontogeny. Our results suggest that multilateral research is required for understanding the fickle ontogeny of natural male-sterile polyploid.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

1995 ◽  
Vol 53 ◽  
pp. 978-979
Author(s):  
G. M. Hutchins ◽  
J. S. Gardner
Keyword(s):  
Growth And Development ◽  
Furfuryl Alcohol ◽  
Apical Meristem ◽  
Plant Cells ◽  
Triticum Aestivum L ◽  
Morphological Development ◽  
Naturally Occurring ◽  
Chinese Spring Wheat ◽  
Sem Study ◽  
Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

A scanning electron microscopic study of the eggs of Culicoides variipennis (Diptera: Ceratopogonidae)

1987 ◽  
Vol 45 ◽  
pp. 884-885 ◽  
Author(s):  
R. A. Nunamaker ◽  
C. E. Nunamaker ◽  
B. C. Wick
Keyword(s):  
Distinct Species ◽  
Hemorrhagic Disease ◽  
Insect Vector ◽  
Electron Microscopic ◽  
Important Species ◽  
Scanning Electron Microscopic Study ◽  
Laboratory Colony ◽  
Culicoides Variipennis ◽  
Morphological Differences ◽  
Scanning Electron

Culicoides variipennis (Coquillett) is probably the most economically important species of biting midge in the U.S. due to its involvement in the transmission of bluetongue (BT) disease of sheep, cattle and ruminant wildlife, and epizootic hemorrhagic disease (EHD) of deer. Proposals have been made to recognize the eastern and western populations of this insect vector as distinct species. Others recommend use of the term “variipennis complex” until such time that the necessary biosystematic studies have been made to determine the genetic nature and/or minute morphological differences within the population structure over the entire geographic range of the species. Increasingly, students of ootaxonomy are relying on scanning electron microscopy (SEM) to assess chorionic features. This study was undertaken to provide comparative chorionic data for the C. variipennis complex.Culicoides variipennis eggs were collected from a laboratory colony maintained in Laramie, Wyoming.

Morphologic differences between abdominal and inguinal testes in stallions

1987 ◽  
Vol 45 ◽  
pp. 820-821
Author(s):  
F. Al-Bagdadi ◽  
D. Hoyt ◽  
P. Karns ◽  
G. Martin ◽  
M. Memon ◽  
...  
Keyword(s):  
Carcinoma Cells ◽  
Genital System ◽  
Diagnosis And Prognosis ◽  
Male Genital System ◽  
Morphological Differences ◽  
Hormone Imbalance ◽  
Made In ◽  
Male Genital

The most frequently occuring abnormality of the male genital system in mammals is the failure of one or both testes to descend into the scrotum. The reasons for abdominal or inguinal retention of testes could be anatomic malformation, faulty development or hormone imbalance.Cryptorchidism has been associated with either greatly reduced or absent spermatogenesis (Kaueakami et al, 1984), and being a source of neoplasia. According to Stick (1980), germinal carcinoma cells have been believed to be the cause of teratomas in equine cryptorchid testicles. Neoplasia has been reported in descended testes of unilateral cryptorchid patients (Martin et al, 1981).No distinction has been made in relating the problem of cryptorchid testes to inguinal or abdominal retention. The purpose of this study is to record the morphological differences between inguinal and abdominal cryptorchid testes as an aid in diagnosis and prognosis.

Observation of pseudo 10-fold symmetry in the ordered iron-zinc delta phase

1992 ◽  
Vol 50 (1) ◽  
pp. 36-37
Author(s):  
L. A. Giannuzzi ◽  
A. S. Ramani ◽  
P. R. Howell ◽  
H. W. Pickering ◽  
W. R. Bitler
Keyword(s):  
Single Phase ◽  
X Ray Diffraction ◽  
Rich Region ◽  
Average Cell ◽  
X Ray ◽  
Delta Phase ◽  
Cell Dimensions ◽  
Δ Phase ◽  
Morphological Differences ◽  
Concentration Discontinuity

The δ phase is a Zn-rich intermetallic, having a composition range of ∼ 86.5 - 92.0 atomic percent Zn, and is stable up to 665°C. The stoichiometry of the δ phase has been reported as FeZn7 and FeZn10 The deviation in stoichiometry can be attributed to variations in alloy composition used by each investigator. The structure of the δ phase, as determined by powder x-ray diffraction, is hexagonal (P63mc or P63/mmc) with cell dimensions a = 1.28 nm, c = 5.76 nm, and 555±8 atoms per unit cell. Later work suggested that the layer produced by hot-dip galvanizing should be considered as two distinct phases which are characterized by their morphological differences, namely: the iron-rich region with a compact appearance (δk) and the zinc-rich region with a columnar or palisade microstructure (δp). The sub-division of the δ phase was also based on differences in diffusion behavior, and a concentration discontinuity across the δp/δk boundary. However, work utilizing Weisenberg photographs on δ single crystals reported that the variation in lattice parameters with composition was small and hence, structurally, the δk phase and the δp phase were the same and should be thought of as a single phase, δ. Bastin et al. determined the average cell dimensions to be a = 1.28 nm and c = 5.71 nm, and suggested that perhaps some kind of ordering process, which would not be observed by x-ray diffraction, may be responsible for the morphological differences within the δ phase.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

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