THE WOOD STRUCTURE OF SOME ARIZONAN AND CALIFORNIAN SPECIES OF CUPRESSUS

1954 ◽  
Vol 32 (1) ◽  
pp. 285-307 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Cell Walls ◽  
Morphological Characteristics ◽  
Intraspecific Variability ◽  
Structural Features ◽  
Species Differentiation ◽  
Wood Structure ◽  
Mean Values ◽  
Interspecific Differences ◽  
Ray Cells ◽  
Ray Cell

The microscopic wood structure of nine species of Cupressus native to Arizona and California was studied from approximately 700 samples. Tracheid and ray cell dimensions, size and distribution of rays, size and arrangement of pits, and thickness of cell walls were found to vary in different parts of the tree, the trends resembling those in other Cupressaceae. Comparisons of the data relating to homologous wood samples revealed slight interspecific differences in mean values for some structural features, but the range of intraspecific variability was usually broad. No single microscopic character was discovered which alone could be considered reliable for species differentiation, but certain features such as the frequency of rays, size of crossing field pits, size of tracheids and ray cells, and thickness of ray cell walls may prove valuable for diagnostic purposes when used together. As in the case of morphological characteristics, species differentiation apparently rests upon slight differences in several characters rather than invariable or marked divergence in single features.

THE MICROSCOPIC WOOD STRUCTURE OF NORTH AMERICAN SPECIES OF CHAMAECYPARIS

1952 ◽  
Vol 30 (2) ◽  
pp. 170-187 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Cell Walls ◽  
Intraspecific Variability ◽  
Structural Features ◽  
Width Ratio ◽  
Mean Values ◽  
Anatomical Features ◽  
Cell Dimensions ◽  
Ray Cells ◽  
Ray Parenchyma Cells ◽  
Ray Cell

Trends in variation in different parts of the tree with regard to such anatomical features as tracheid and ray cell dimensions, size and distribution of rays, size and arrangement of pits, and thickness of cell walls resemble those recorded for other Cupressaceae. Comparative data relating to homologous wood samples show slight differences in mean values between the three American species of Chamaecyparis, but the intraspecific variability is usually so extensive that the specific ranges overlap widely. No single microscopic character seems completely reliable for diagnostic purposes, but certain structural features are valuable when used together. These are the frequency of ray tracheids in newly formed rays, the thickness of the horizontal and end walls of ray parenchyma cells, the number of pits per crossing field, and the height/width ratio of ray cells viewed tangentially.

scholarly journals Temperature Response of Fragaria Species

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 645e-645
Author(s):  
Douglas D. Archbold
Keyword(s):  
Significant Variation ◽  
Temperature Response ◽  
Intraspecific Variability ◽  
Mean Value ◽  
Controlled Environment ◽  
Relative Growth ◽  
Mean Values ◽  
Interspecific Differences ◽  
C Value ◽  
Net Assimilation

Plants of a diverse collection of Fragaria clones from a range of native habitats representing F. chiloensis, F. virginiana, F. virginiana glauca, and F. vesca, were grown in a controlled environment at one of three day/night temperatures, 15/15, 23/15, or 31/15°C. Relative growth rate (RGR) and net assimilation rate (NAR) were estimated from plant leaf areas and total dry weights. At 23/15°C, the species mean RGR and NAR values were comparable although clones within species exhibited significant variation. At 15/15 and 31/15°C, RGR and NAR for species were lower than at 23/15°C. At 31/15°C, chiloensis and vesca mean values were reduced more than the others, to less than 50% the 23/15°C values. Also, NAR declined most for chiloensis, to 45% the 23/15°C value. At 15/15°C, virginiana had much higher RGR and NAR values than the other species, and its NAR mean value was greater than at 23/15°C. Although the species means would suggest that there are interspecific differences in temperature response, intraspecific variability was also large. Thus, classifying Fragaria species by temperature response may be an over-generalization.

The Potential of Fucose-Containing Sulfated Polysaccharides As Scaffolds for Biomedical Applications

2019 ◽  
Vol 26 (35) ◽  
pp. 6399-6411 ◽  
Author(s):  
Cláudia Nunes ◽  
Manuel A. Coimbra
Keyword(s):  
Tissue Regeneration ◽  
Cell Walls ◽  
Biomedical Applications ◽  
Structural Features ◽  
Therapeutic Agents ◽  
Sulfated Polysaccharides ◽  
Clinical Use ◽  
Health Related ◽  
Pathogen Inhibition ◽  
Health Applications

Marine environments have a high quantity and diversity of sulfated polysaccharides. In coastal regions brown algae are the most abundant biomass producers and their cell walls have fucosecontaining sulfated polysaccharides (FCSP), known as fucans and/or fucoidans. These sulfated compounds have been widely researched for their biomedical properties, namely the immunomodulatory, haemostasis, pathogen inhibition, anti-inflammatory capacity, and antitumoral. These activities are probably due to their ability to mimic the carbohydrate moieties of mammalian glycosaminoglycans. Therefore, the FCSP are interesting compounds for application in health-related subjects, mainly for developing scaffolds for delivery systems or tissue regeneration. FCSP showed potential for these applications also due to their ability to form stable 3D structures with other polymers able to entrap therapeutic agents or cell and growth factors, besides their biocompatibility and biodegradability. However, for the clinical use of these biopolymers well-defined reproducible molecules are required in order to accurately establish relationships between structural features and human health applications.

Effect of particle size and delignification on the rate of digestion of hemicellulose and cellulose by cellulase in mature pangola grass stems

1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Particle Size Reduction ◽  
Digitaria Decumbens ◽  
Hemicellulose Degradation ◽  
Before And After ◽  
The Difference

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.

Intraspecific variability of morphological characters in the species-rich deep-sea genus Acantholaimus Allgén, 1933 (Nematoda: Chromadoridae)

Nematology ◽  
2016 ◽  
Vol 18 (4) ◽  
pp. 455-473 ◽  
Author(s):  
Dmitry M. Miljutin ◽  
Maria A. Miljutina
Keyword(s):  
Deep Sea ◽  
Intraspecific Variability ◽  
Morphological Characters ◽  
Molecular Data ◽  
Species Discrimination ◽  
Species Differentiation ◽  
Lateral Field ◽  
Operational Taxonomic Units ◽  
General Arrangement ◽  
Taxonomic Approach

Acantholaimusis a species-rich genus of deep-sea nematodes, often with dozens of species found at the same locality but each represented by single or few individuals. Species discrimination by morphological characters in this genus is therefore often difficult due to transitional forms that may be referred to several species because of lack of data on intraspecific variability. The aim of this study was to evaluate the intraspecific variability of morphological characters that are most often used inAcantholaimustaxonomy, in order to distinguish those which are most informative for species differentiation. A reverse taxonomic approach was applied for initial species discrimination. Two loci, one each from small and large subunits of rRNA, were sequenced for 59Acantholaimusspecimens from two deep-sea locations. Twenty-seven Molecular Operational Taxonomic Units (MOTU) were identified, of which 12 were represented by more than one individual. These were then analysed for intraspecific variability in morphological characters. Some of the examined characters showed high intraspecific variability; specifically: length of cephalic setae; distance from anterior end to amphid; shape of anterior setae; position and arrangement of cervical setae. In the absence of genetic data, these characters should be used with caution for differential diagnoses or species discrimination. Other characters were more conservative within the same MOTU: body proportions; length of outer labial setae; amphidial diam.; appearance of lateral field; general arrangement of cervical setae; and shape of tail. These characters may be successfully used for species discrimination in the absence of molecular data.

Cambial activity and ray cell abundance in Acer saccharum

1977 ◽  
Vol 55 (20) ◽  
pp. 2559-2564 ◽  
Author(s):  
R. A. Gregory
Keyword(s):  
Growth Rate ◽  
Acer Saccharum ◽  
Unit Area ◽  
Ring Width ◽  
Cambial Activity ◽  
Relative Volume ◽  
Annual Ring Width ◽  
Ray Cells ◽  
Fusiform Initials ◽  
Ray Cell

The ratio of ray and ray cell initials to fusiform initials of the vascular cambium relative to radial growth rate as reflected in the secondary xylem was studied in stems of Acer saccharum Marsh. Ray initials increased in size as they aged, slowly when growth rate was low, rapidly when it was high, but there was little fluctuation in the number of rays per unit of tangential area; as the cambium increased in circumference, the older, larger rays diverged and new small rays arose in intervening areas, thus maintaining a uniform unit area population independent of growth rate. However, since ray size increased rapidly when growth rate was high, the unit area population of ray cells rose abruptly with accelerating growth rate: the relative volume of xylem ray tissue rose from 8.6 to 12.7% of the total xylem volume when annual ring width increased from 1 to 7 mm. When fast growth was not maintained, the unit area population of ray cells declined slowly as the large rays diverged.

scholarly journals Calculation of Differential Propagation Constant Determined by Plant Morphology Using Polarimetric Measurement

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Chufeng Hu ◽  
Nanjing Li
Keyword(s):  
Electromagnetic Wave ◽  
Measurement System ◽  
Random Distribution ◽  
Propagation Constant ◽  
Morphological Characteristics ◽  
Plant Morphology ◽  
Structural Features ◽  
Low Frequencies ◽  
Mathematical Relation ◽  
Power Profile

The morphology of vegetation greatly impacts propagation of polarized electromagnetic wave. In order to validate this phenomenon, the mathematical relation between the differential propagation constant of forest vegetation and of its polarized echo is quantitatively derived by using backscattering power profile. The fluctuation of differential propagation constant with frequency is analyzed by combining the morphological characteristics of vegetation. The accurate copolarized data of 3–10 GHz frequency-domain of small trees are obtained by indoor wideband polarimetric measurement system. The results show that morphological characteristics of vegetation at different frequencies can be obtained by the differential propagation constant of polarized electromagnetic wave. At low frequencies, the plants with structural features presented oriented distribution. However, the plants show random distribution of the echoes at higher frequencies, which is mainly from the canopy. The research provides important information to choose the coherence models employed in the parameters retrieval of vegetations.

scholarly journals STRUCTURAL AND CHEMICAL CHARACTERISTIC OF PECTIN FROM PICEA ABIES GREENERY

2020 ◽  
pp. 59-71
Author(s):  
Evgeniy Gennad'yevich Shakhmatov ◽  
Elena Nikolayevna Makarova
Keyword(s):  
Cell Walls ◽  
New Technologies ◽  
Chemical Characteristic ◽  
Structural Features ◽  
Exchange Chromatography ◽  
Raw Material ◽  
Rhamnogalacturonan I ◽  
Wood Processing ◽  
Potential Source ◽  
Pectin Substances

The present work aimed to determine structural features of polysaccharides derived from the P. abies foliage by extraction with a (NH4)2C2O4 solution. The isolated polysaccharide was studied in detail by the methods of ion exchange chromatography, partial acidic hydrolys and NMR spectroscopy. It was shown that this polysaccharide contained polymers of various structures. The major constituents of PAO were low-methoxyl and low-acetylated 1,4-a-D-galacturonan and by minor parts of partly 2-O- and/or 3-O- acetylated rhamnogalacturonan-I (RG-I). The side carbohydrate chains of the branched region of RG-I were represented predominantly by highly branched 1,5-a-L-arabinan and minor portions of 1,4-β-D-galactan. In addition to the dominant pectins, polysaccharide PAO contained binding glycans of the glucomannans class, which indicated a close interaction of these polysaccharides in the cell walls. Thus, the structural features of pectin woody P. abies, extracted with a solution of (NH4)2C2O4, were first determined. It can be concluded that P. abies woody greens, a large tonnage waste from the wood processing industry, can be considered as a potential source of pectin substances. The results of studying the structure of components of woody green P. abies can be the basis for the development and improvement of new technologies for the integrated use of this raw material.

The epidermis in Passerina/ (Thymelaeaceae): structure, function and taxonomic significance

Bothalia ◽  
2000 ◽  
Vol 30 (1) ◽  
pp. 69-86 ◽  
Author(s):  
C. L. Bredenkamp ◽  
A. E. Van Wyk
Keyword(s):  
Cell Walls ◽  
Mediterranean Climate ◽  
High Light Intensity ◽  
Epidermal Cells ◽  
Cell Orientation ◽  
Abaxial Surface ◽  
Epidermal Structure ◽  
Interspecific Differences ◽  
Epidermal Features ◽  
Structural Adaptations

Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.

Geographical variability of Lepyronia coleoptrata (Linnaeus, 1758) (Hemiptera: Cercopoidea) across Russia

Zootaxa ◽  
2019 ◽  
Vol 4543 (3) ◽  
pp. 401
Author(s):  
DMITRI YU. TISHECHKIN
Keyword(s):  
Body Size ◽  
Russian Far East ◽  
Far East ◽  
Intraspecific Variability ◽  
Geographical Variability ◽  
Interspecific Differences ◽  
The Far East ◽  
Male Calling ◽  
Far Eastern ◽  
The Russian Far East

Comparative analysis of body size, coloration, penis shape, and male calling signals of Lepyronia coleoptrata from different localities in European Russia, Northern Kazakhstan, Siberia, and the Russian Far East showed that all populations studied belong to the same species. A clear boundary between European and the Far-Eastern subspecies can only be drawn based on body size and proportions. Light coloration is typical of European populations; on the contrary, in the Far East only dark specimens occur, but in Siberia a mixture of different forms presents. Penis shape and male calling signal pattern do not demonstrate geographical variability. The range of intraspecific variability of these traits is far less than interspecific differences between L. coleoptrata, L. koreana, and L. okadae. 

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