Selection of alfalfa for a lower initial rate of digestion and corresponding changes in epidermal and mesophyll cell wall thickness

1993 ◽  
Vol 73 (1) ◽  
pp. 111-122 ◽  
Author(s):  
B. P. Goplen ◽  
R. E. Howarth ◽  
G. L. Lees
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Walls ◽  
Dry Matter ◽  
Initial Rate ◽  
Environmental Influence ◽  
Mesophyll Cell ◽  
Cell Wall Thickness ◽  
Advanced Stage ◽  
Selection Of

A modified nylon bag technique, described in detail in this paper, appears to be an effective method of selecting for a lower initial rate of digestion (IRD) in alfalfa. Breeding for reduced IRD in alfalfa resulted in a 15% reduction in 4-h dry matter disappearance (DMD) after three cycles of selection (ultimate goal of 25–30 % reduction for a bloat-safe alfalfa). No further reduction in IRD occurred with a 4th cycle of selection. The IRD characteristic appears to be expressed at early stages of vegetative growth (pre-bud to early bud) and not at a more advanced stage of maturity (mid-bud to early bloom). The IRD characteristic also appears to be subject to environmental influence. Alfalfa plants selected for reduced IRD have consistently thicker cell walls compared to the unselected alfalfa check cv. Beaver. The advanced cycle 4 LIRD synthetic is being increased for subsequent pasture trials and assessment of bloat reduction. Key words: Nylon bag technique, cell rupture, pasture bloat, initial rate of digestion, cell wall thickness

scholarly journals Differences in cell wall of thin and thick filaments of cyanobacterium Aphanizomenon gracile SAG 31.79 and their implications for different resistance to Daphnia grazing

2016 ◽  
Author(s):  
Lukasz Wejnerowski ◽  
Slawek Cerbin ◽  
Maria K. Wojciechowicz ◽  
Marcin K. Dziuba
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Walls ◽  
Cell Wall Thickness ◽  
Filamentous Cyanobacterium ◽  
Thin Sections ◽  
Thick Filaments ◽  
Transmission Electron ◽  
The Difference ◽  
Aphanizomenon Gracile

<p>Recent studies have shown that the filamentous cyanobacterium <em>Aphanizomenon gracile</em> Lemmermann, strain SAG 31.79, consists of two types of filaments that differ in thickness. These two types are known to vary in resistance to <em>Daphnia</em> <em>magna</em> grazing: thin filaments (&lt;2.5 µm) are more vulnerable to grazing than the thick ones (&gt;2.5 µm). In this study, we investigated whether the difference in the vulnerability to grazing of thin and thick filaments is a result of different thickness of their cell walls, a filament stiffness determinant. We expected thick filaments to have thicker cell walls than the thin ones. Additionally, we analysed whether cell wall thickness correlates with filament thickness regardless of the filament type. A morphometric analysis of cell walls was performed using transmission electron micrographs of ultra-thin sections of the batch-cultured cyanobacterial material.  Our study revealed that the thin type of filaments had thinner cell walls than the thick filaments. Moreover, cell wall thickness was positively correlated with filament thickness. TEM (transmission electron microscopy) observations also revealed that the thin type of filaments was often at different stages of autocatalytic cell destruction, which was mainly manifested in the increase in cell vacuolization and degradation of the cytoplasm content. Based on our findings, we assume that previously reported higher resistance of thick filaments to <em>Daphnia</em> grazing results from greater stiffness and excellent physiological conditions of thick filaments. </p>

Variation in Fibre and Parenchyma Wall Thickness in Culms of the Bamboo Sinobambusa Tootsik

IAWA Journal ◽  
1988 ◽  
Vol 9 (4) ◽  
pp. 353-361 ◽  
Author(s):  
K. L. Alvin ◽  
R. J. Murphy
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Wall Thickness ◽  
Cell Walls ◽  
Basic Density ◽  
Cell Wall Thickness ◽  
Ground Tissue ◽  
Average Cell ◽  
Obvious Change ◽  
Cortical Parenchyma

The mid-internodal anatomy of three culms estimated to be less than one, one to two and more than two years old respectively, has been investigated revealing significant increases in average cell wall thickness of the fibres and ground tissue parenchyma. The basic density of the culm also increases. Cortical parenchyma, in contrast, shows no obvious change. Both fibres and parenchyma appear to retain living protoplasts . Progressive thickening of the cell walls over a period of perhaps several years would have important implications for harvesting and utilisation of bamboo culms and would explain reported changes in certain mechanical properties with ageing.

scholarly journals Lamina Cell Shape and Cell Wall Thickness Are Useful Indicators for Metal Tolerance—An Example in Bryophytes

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 274
Author(s):  
Katharina Petschinger ◽  
Wolfram Adlassnig ◽  
Marko S. Sabovljevic ◽  
Ingeborg Lang
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Walls ◽  
Cell Shape ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Cell Wall Thickness ◽  
Pleurozium Schreberi ◽  
Sensitive Species ◽  
Good Marker

Bryophytes are widely used to monitor air quality. Due to the lack of a cuticle, their cells can be compared to the roots of crop plants. This study aimed to test a hypothetical relation between metal tolerance and cell shape in biomonitoring mosses (Hypnum cupressiforme, Pleurozium schreberi, Pseudoscleropodium purum) and metal sensitive species (Physcomitrium patens, Plagiomnium affine). The tolerance experiments were conducted on leafy gametophytes exposed to solutions of ZnSO4, ZnCl2, and FeSO4 in graded concentrations of 1 M to 10−8 M. Plasmolysis in D-mannitol (0.8 M) was used as a viability measure. The selected species differed significantly in lamina cell shape, cell wall thickness, and metal tolerance. In those tested mosses, the lamina cell shape correlated significantly with the heavy metal tolerance, and we found differences for ZnSO4 and ZnCl2. Biomonitoring species with long and thin cells proved more tolerant than species with isodiametric cells. For the latter, “death zones” at intermediate metal concentrations were found upon exposure to ZnSO4. Species with a greater tolerance towards FeSO4 and ZnSO4 had thicker cell walls than less tolerant species. Hence, cell shape as a protoplast-to-wall ratio, in combination with cell wall thickness, could be a good marker for metal tolerance.

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

Characterization of microstructures of SAN foam core using micro-computed tomography

2021 ◽  
pp. 026248932110068
Author(s):  
Youming Chen ◽  
Raj Das ◽  
Hui Wang ◽  
Mark Battley
Keyword(s):  
Cell Wall ◽  
Cell Size ◽  
Wall Thickness ◽  
Strain Localization ◽  
Cell Wall Thickness ◽  
Micro Computed Tomography ◽  
Average Cell Size ◽  
Average Cell ◽  
3D Images ◽  
Compressive Tests

In this study, the microstructure of a SAN foam was imaged using a micro-CT scanner. Through image processing and analysis, variations in density, cell wall thickness and cell size in the foam were quantitatively explored. It is found that cells in the foam are not elongated in the thickness (or rise) direction of foam sheets, but rather equiaxed. Cell walls in the foam are significantly straight. Density, cell size and cell wall thickness all vary along the thickness direction of foam sheets. The low density in the vicinity of one face of foam sheets leads to low compressive stiffness and strength, resulting in the strain localization observed in our previous compressive tests. For M80, large open cells on the top face of foam sheets are likely to buckle in compressive tests, therefore being another potential contributor to the strain localization as well. The average cell wall thickness measured from 2D slice images is around 1.4 times that measured from 3D images, and the average cell size measured from 2D slice images is about 13.8% smaller than that measured from 3D images. The dispersions of cell wall thickness measured from 2D slice images are 1.16–1.20 times those measured from 3D images. The dispersions of cell size measured from 2D slice images are 1.12–1.36 times those measured from 3D images.

Summer temperature in northeastern Siberia since 1642 reconstructed from tracheid dimensions and cell numbers of Larix cajanderi

2003 ◽  
Vol 33 (10) ◽  
pp. 1905-1914 ◽  
Author(s):  
Irina P Panyushkina ◽  
Malcolm K Hughes ◽  
Eugene A Vaganov ◽  
Martin AR Munro
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Number ◽  
Cell Wall Thickness ◽  
Cell Dimension ◽  
Cell Numbers ◽  
Age Related ◽  
Cambial Age ◽  
Northeastern Siberia ◽  
Larix Cajanderi

We reconstructed air temperature for two periods in the growth season from cell dimension and cell number variability in cross-dated tree rings of Larix cajanderi Mayr. from northeastern Siberia. Thirteen tree-ring chronologies based on cell size, cell wall thickness, and cell number were developed for AD 1642–1993. No clear evidence was found of an age-related trend in cell dimensions in the sampled materials, but cell numbers were correlated with cambial age. The chronologies contain strong temperature signals associated with the timing of xylem growth. We obtained reliable reconstructions of mean June temperature from the total cell number and July–September temperature from the cell wall thickness of latewood. June temperature and July–September temperature covaried for most of the period from AD 1642 to AD 1978. After that time, June temperature became cooler relative to July–September temperature. This difference caused disproportional changes in earlywood tracheids because of the late start of growth and cool conditions in June followed by warming during the rest of the season. The identification of this unusual recent change has shown that intraseasonal resolution may be achieved by cell dimension and cell number chronologies.

Variation in xylem anatomy of selected populations of lodgepole pine

2001 ◽  
Vol 31 (11) ◽  
pp. 2049-2057 ◽  
Author(s):  
Tongli Wang ◽  
Sally N Aitken
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Slow Growth ◽  
Lodgepole Pine ◽  
High Density ◽  
Cell Wall Thickness ◽  
Fast Growth ◽  
Low Density ◽  
Xylem Anatomy ◽  
Latewood Density

Variation in xylem anatomy among selected populations of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) was examined using digital image analysis based on an annual growth ring (age 10) per tree. Four subpopulations were selected using the following criteria for height growth and wood density: (i) fast growth and high density; (ii) slow growth and high density; (iii) fast growth and low density; and (iv) slow growth and low density. Significant differences were found among subpopulations for several anatomical parameters including tracheid density, lumen size, and cell wall thickness that may affect the economic value and utilization of wood. Principal component analysis indicate that the first four principal components (PCs) were associated with (i) ring area (PC1), (ii) earlywood density (PC2), (iii) latewood density (PC3), and (iv) lumen shape in earlywood (PC4), suggesting that these aspects of wood properties and growth are controlled by different sets of genes. Relative contributions of total number of tracheids, tracheid lumen size, and cell wall thickness to ring area and correlations between cell wall area proportion and X-ray density are discussed.

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