GROWTH STRAINS AND RELATED WOOD STRUCTURES IN THE LEANING TRUNKS AND BRANCHES OF TROCHODENDRON ARALIOIDES - A VESSEL-LESS DICOTYLEDON

Leaning trunks and branches of Trochodendron aralioides Sieb. & Zucc., a primitive vessel-less dicotyledon, show increased radial growth and gelatinous fibers on the upper side similar to the features found in dicotyledons with vessels. The patterns of peripheral longitudinal growth strain are variable among trees but similar at different heights within the same leaning trunk. Growth strains on the lower side of the trunks are very small but they are relatively large on the lower side of the branches. Growth stress in the branches is partly affected by the gravitational bending stress, which would be exerted mostly on the lower side. Large spring back strains of branches are associated with large surface strains. Both the microfibril angle (MFA) and the percentage area of gelatinous fiber show positive relationships with the measured strains. The MFA of the S2 wall layer in tracheids in the opposite wood is 24.6 ± 2.2°, whereas the MFA of gelatinous layer in the tension wood is only 14.2 ± 2.7°. The difference of MFA between the gelatinous fibers and the opposite wood is one of the factors accounting for the large contracting force for reorientation.

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ANATOMICAL CHARACTERIZATION OF TENSION WOOD IN Hevea brasiliensis (Willd. ex A. Juss.) Mull. Arg.

Revista Árvore ◽

10.1590/0100-67622016000600016 ◽

2016 ◽

Vol 40 (6) ◽

pp. 1099-1107

Author(s):

Letícia Maria Alves Ramos ◽

João Vicente de Figueiredo Latorraca ◽

Thayanne Caroline Castor Neto ◽

Letícia Souza Martins ◽

Elias Taylor Durgante Severo

Keyword(s):

Hevea Brasiliensis ◽

Fiber Length ◽

Tension Wood ◽

Rubber Tree ◽

Microfibril Angle ◽

Vessel Diameter ◽

Longitudinal Distribution ◽

Axial Parenchyma ◽

Gelatinous Fibers ◽

Gelatinous Fiber

ABSTRACT Tension wood is an important anatomical structure for its participation in the orientation of the trunk and the architecture of the branches as a function of structural reinforcement. However, its presence in large amounts significantly affects the technological properties of wood, just as in the rubber tree. Nevertheless, there is still demand for information about the origin, distribution and structural features in this species. Thus, this study aims to characterize the cellular structures in tension and opposite wood in Hevea brasiliensis (rubber tree), as well as its radial and longitudinal distribution. Discs at the base and the middle of the commercial logs were collected from three trees in a commercial plantation located in Tabapoã - SP. Tangential diameter of vessels, fiber length (gelatinous and non-gelatinous fibers), microfibril angle and proportionality of cellular elements (vessels, axial parenchyma, ray, gelatinous fibers and non-gelatinous fibers) were measured, and influence of gelatinous fiber presence in vessel diameter was observed. Gelatinous fibers were observed in the two types of wood and in the two trunk heights. Both types of wood were distinguished by gelatinous fiber length and the proportion of axial parenchyma. The tension wood in mid-trunk was the most different, with long gelatinous fibers and less abundant, larger vessel diameter and vessel proportion. Moreover, smaller vessel diameter was observed in the regions with a high proportion of gelatinous fibers, suggesting that the plant invests more support than in liquid transport.

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Tension Wood and Oppositewood in 21 Tropical Rain Forest Species

IAWA Journal ◽

10.1163/22941932-90000159 ◽

2006 ◽

Vol 27 (4) ◽

pp. 341-376 ◽

Cited By ~ 43

Author(s):

Julien Ruelle ◽

Bruno Clair ◽

Jacques Beauchêne ◽

Marie Françoise Prévost ◽

Meriem Fournier

Keyword(s):

Rain Forest ◽

Tropical Rain Forest ◽

Tension Wood ◽

Fibre Diameter ◽

Microfibril Angle ◽

Ultrastructural Level ◽

Growth Stress ◽

Opposite Wood ◽

Two Samples ◽

French Guyana

The anatomy of tension wood and opposite wood was compared in 21 tropical rain forest trees from 21 species belonging to 18 families from French Guyana. Wood specimens were taken from the upper and lower sides of naturally tilted trees. Measurement of the growth stress level ensured that the two samples were taken from wood tissues in a different mechanical state: highly tensile-stressed wood on the upper side, called tension wood and normally tensile-stressed wood on the lower side, called opposite wood. Quantitative parameters relating to fibres and vessels were measured on transverse sections of both tension and opposite wood to check if certain criteria can easily discriminate the two kinds of wood. We observed a decrease in the frequency of vessels in the tension wood in all the trees studied. Other criteria concerning shape and surface area of the vessels, fibre diameter or cell wall thickness did not reveal any general trend. At the ultrastructural level, we observed that the microfibril angle in the tension wood sample was lower than in opposite wood in all the trees except one (Licania membranacea).

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ECCENTRIC GROWTH AND GROWTH STRESS IN INCLINED STEMS OF GNETUM GNEMON

IAWA Journal ◽

10.1163/22941932-20150107 ◽

2015 ◽

Vol 36 (4) ◽

pp. 365-377 ◽

Cited By ~ 3

Author(s):

Tatsuya Shirai ◽

Hiroyuki Yamamoto ◽

Masato Yoshida ◽

Mikuri Inatsugu ◽

Chisato Ko ◽

...

Keyword(s):

Secondary Xylem ◽

Secondary Growth ◽

Microfibril Angle ◽

Chemical Properties ◽

Growth Stress ◽

Reaction Wood ◽

Wood Fibers ◽

Gelatinous Fibers ◽

Gnetum Gnemon ◽

Negative Gravitropism

Gnetum gnemon L. (Gnetales) forms hardwood-like secondary xylem in its trunks and branches although it is a gymnosperm. The present study tested the surface growth stress in relation to anatomical and chemical properties of the secondary xylem in inclined and vertical stems of G. gnemon using morphological and chemical composition analyses. Secondary growth was promoted on the upper half of the cross section in an inclined stem; at the same time, tensile growth stress increased on the upper side and decreased on the lower side of the inclined stem. However, formation of reaction wood fibers was not detected on either side. The microfibril angle was associated with differences in tensile growth stress. Thus, we conclude that negative gravitropism in G. gnemon is caused by a synergistic effect of increased tensile growth stress as well as the promotion of secondary growth on the upper side of the inclined stem. Our results are comparable to the negative gravitropism observed in the family Magnoliaceae, which does not form gelatinous fibers in its tension wood.

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MICROFIBRIL ANGLE OF THE S1 CELL WALL LAYER OF NORWAY SPRUCE COMPRESSION WOOD TRACHEIDS

IAWA Journal ◽

10.1163/22941932-90000374 ◽

2004 ◽

Vol 25 (4) ◽

pp. 415-423 ◽

Cited By ~ 11

Author(s):

Jonas Brändström

Keyword(s):

Norway Spruce ◽

Compression Wood ◽

Microfibril Angle ◽

Soft Rot ◽

Wall Layer ◽

Thermomechanical Pulp ◽

Ultrastructural Organization ◽

Normal Wood ◽

Cell Wall Layer ◽

Fracture Characteristics

The ultrastructural organization of the outer layer of the secondary wall (i.e. S1 layer) of Norway spruce (Picea abies (L.) Karst.) compression wood tracheids was investigated with emphasis on the microfibril angle. Light microscopy was used to study the orientation of soft rot cavities (viz. microfibril angle) in compression wood tracheids from macerated soft rot degraded wood blocks. In addition, surface and fracture characteristics of compression wood tracheids selected from a thermomechanical pulp were investigated using scanning electron microscopy (SEM). Results showed that the orientation of soft rot cavities varied little between tracheids and the angles were also consistent along the length of individual tracheids. The average S1 microfibril angle in two selected annual rings was 90.0° ± 2.7° and 88.9° ± 2.4° respectively. SEM observations of the compression wood tracheids from the pulp showed distinct fractures between S1 and S2 or within S1 and these fractures were oriented perpendicular to the tracheid axis. It was concluded that the microfibril angle of the S1 layer of compression wood tracheids is higher and less variable than normal wood tracheids. This is considered an adaptation for restraining the compressive forces that act on leaning conifer stems or branches.

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Wood Anatomy of nine Japanese Hardwood species forming reaction wood without gelatinous fibers

IAWA Journal ◽

10.1163/22941932-90000016 ◽

2010 ◽

Vol 31 (2) ◽

pp. 191-202 ◽

Cited By ~ 8

Author(s):

R.S. Sultana ◽

F. Ishiguri ◽

S. Yokota ◽

K. Iizuka ◽

T. Hiraiwa ◽

...

Keyword(s):

Lignin Content ◽

Reaction Wood ◽

Wood Fibers ◽

Acetyl Bromide ◽

Euonymus Alatus ◽

Opposite Wood ◽

Gelatinous Fibers ◽

Hardwood Species ◽

Daphne Odora ◽

Clerodendron Trichotomum

The anatomy of reaction wood was studied in nine naturally growing Japanese hardwood species, all showing eccentric growth on the upper side of their leaning branches. The number of vessels decreased in the xylem of the upper side accompanying the formation of reaction wood. A typical G-layer was not detected in the reaction wood fibers, but an S3 layer was present in all nine species. The cellulose microfibril arrangement with an S helix was similar in the S3 layers of both reaction and opposite wood fibers. A decrease of lignin content occurred in the reaction wood fibers in all nine species. The coniferyl and sinapyl aldehyde units in the lignins were strongly reduced in the S2 layer of reaction wood fibers of four species, i.e., Euscaphis japonica, Rhododendron wadanum, Clerodendron trichotomum, and Daphne odora, and much less so in five other species, i.e., Viburnum dilatatum, Enkianthus subsessilis, Euonymus alatus, Ilex macropoda, and Ilex crenata. The syringyl content was lower in the S2 layer of reaction wood fibers than that in opposite wood of all nine species. On the other hand, chemical analysis of lignin using the acetyl bromide method showed that, among the nine species, lignin content was reduced most strongly in Clerodendron trichotomum. Tension wood-like characteristics are present on the upper side of leaning branches in all nine species, except that G-fibers are absent.

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Trabeculae and Al-accumulation in the wood cells of Melastomataceae species from Brazilian savanna

Botany ◽

10.1139/cjb-2016-0135 ◽

2017 ◽

Vol 95 (5) ◽

pp. 521-530

Author(s):

Camilla Rozindo Dias Milanez ◽

Carmen Regina Marcati ◽

Silvia Rodrigues Machado

Keyword(s):

Wood Anatomy ◽

Gelatinous Fibers ◽

Vessel Elements ◽

Ray Cells ◽

Gelatinous Fiber ◽

The Common ◽

New Perspective ◽

Perforation Plates ◽

First Time ◽

Additional Role

Family Melastomataceae is an important component of the Brazilian Cerrado flora, inhabiting different environments from those with well-drained soils to swamp soil sites. Several members of this family are recognized as aluminum (Al)-accumulating. We studied the wood anatomy of six species of Melastomataceae (Miconia albicans (Sw.) Triana, M. fallax DC., M. chamissois Naudin, M. ligustroides (DC.) Naudin, Microlepis oleaefolia (DC.) Triana, Rhynchanthera dichotoma DC.), growing in different environments of Cerrado, exploring the occurrence of trabeculae and Al-accumulation sites. We processed the material following the usual techniques in wood anatomy and histochemistry. We used a chrome azurol-S spot-test in fresh material to detect Al-accumulation. The common features were diffuse porosity, vessel elements with simple perforation plates and vestured pits, abundant parenchyma-like fiber bands and septate fibers, axial parenchyma scanty to vasicentric, and heterocellular rays. The presence of trabeculae in vessel elements, septa in parenchyma cells, and aluminum in the G-layer of the gelatinous fiber walls, in the septa of fibers, in cambial initials and derivatives cell walls, and in the vacuole of ray cells are recorded for the first time for Melastomataceae. The results of this study indicate an additional role for gelatinous fibers in Al-accumulation, and offer a new perspective on Al-compartmentalization in the wood cells from Cerrado species.

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Evaluation of the sealer/gutta-percha ratio on sets of root section surfaces of some extracted teeth sealed using the cold lateral condensation technique

Journal of Medicine and Life ◽

10.25122/jml-2021-0102 ◽

2021 ◽

Vol 14 (3) ◽

pp. 337-346

Author(s):

Ioana Suciu ◽

◽

Bogdan Dimitriu ◽

Mihai Ciocardel ◽

Mihaela Chirila ◽

...

Keyword(s):

Root Canal ◽

Essential Role ◽

Canal Wall ◽

Root Section ◽

Root Canals ◽

Gutta Percha ◽

Percentage Area ◽

The Difference ◽

Imagej Software

Canal filling must be well adapted to the walls of the root canal to prevent bacterial infiltration. Endodontic seals play an essential role in ensuring tightness, without which the canal filling would suffer infiltrations. This study aimed to evaluate the areas occupied by the two components of the canal filling, as well as the sealer/gutta-percha ratio in the root canals of the maxillary central incisors after their filling using the cold lateral condensation technique with gutta-percha. Thirty extracted upper central incisors were rotatably prepared with ProTaper Universal up to F3 and sealed using the cold lateral condensation technique with gutta-percha. After setting the sealer, the roots of the teeth were sectioned perpendicularly to 1 (L1), 3 (L3), 6 (L6), and 8 (L8) mm from the apex. The surface of the sections was analyzed with a Leica EZ4D stereomicroscope and photographed at two magnification orders: 10x and 25x. The areas corresponding to the gutta-percha, sealer, gaps, and root canal were expressed in pixels using the ImageJ software, version 1.50i. The difference in the representation of sealer areas, gutta-percha and voids was statistically significantly different for all four sections analyzed. The best adaptation of the canal obturation was observed in L1 and L3. The gutta-percha area was statistically significantly higher than that of the sealer for the L1, L3, and L6 levels, while the sealer/gutta-percha ratio recorded the lowest value at the L3 level (0, 30) and the highest at its L8 (0.70) level, without registering statistically significant differences regarding the area at the four analyzed levels. The voids were mostly absent or recorded a minimal percentage area (<1%). Cold lateral condensation of gutta-percha has led to a good adaptation of gutta-percha to the root canal wall, with a small amount of sealer, especially to the sections made at 3 mm from the apex. Given the limitations of this study, we noted that the voids were few – observed in the 6 and 8 mm sections – and were negligible in many cases.

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Comparative studies on wood structure and microtensile properties between compression and opposite wood fibers of Chinese fir plantation

Journal of Wood Science ◽

10.1186/s10086-021-01945-z ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Zhu Li ◽

Tianyi Zhan ◽

Michaela Eder ◽

Jiali Jiang ◽

Jianxiong Lyu ◽

...

Keyword(s):

Cellulose Microfibril ◽

Microfibril Angle ◽

Tensile Modulus ◽

Scientific Basis ◽

Ultimate Tensile Stress ◽

Chinese Fir ◽

Cellulose Content ◽

Wood Fibers ◽

Opposite Wood ◽

Chinese Fir Plantation

AbstractThe microtensile properties of mechanically isolated compression wood (CW) and opposite wood (OW) tracheids of Chinese fir (Cunninghamia lanceolata) were investigated and discussed with respect to their structure. Major differences in the tensile modulus and ultimate tensile stress were found between CW and OW fibers. Compared to OW, CW showed a larger cellulose microfibril angle, less cellulose content and probably more pits, resulting in lower tensile properties. These findings contribute to a further understanding of the structural–mechanical relationships of Chinese fir wood at the cell and cell wall level, and provide a scientific basis for better utilization of plantation softwood.

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Anatomical and chemical factors affecting tensile growth stress in Eucalyptus grandis plantations at different latitudes in Brazil

Canadian Journal of Forest Research ◽

10.1139/x11-161 ◽

2012 ◽

Vol 42 (1) ◽

pp. 134-140 ◽

Cited By ~ 6

Author(s):

Miho Kojima ◽

Hiroyuki Yamamoto ◽

Koichiro Saegusa ◽

Fabio Minoru Yamaji ◽

Masato Yoshida ◽

...

Keyword(s):

Lignin Content ◽

Microfibril Angle ◽

Eucalyptus Grandis ◽

Middle Layer ◽

Growth Stress ◽

Cellulose Content ◽

Factors Affecting ◽

Wide Range ◽

Chemical Factors ◽

Processing Defects

The key to using planted Eucalyptus as timber lies in controlling the characteristic high tensile growth stress that often causes serious processing defects in sawn logs and lumber. In the present study, we investigated variations in the longitudinal released strain (RS) of surface growth stress in stems of Eucalyptus grandis W. Hill ex Maiden planted in a wide range of latitudes in Brazil and established relationships between RS measurements and anatomical and chemical factors. Cellulose and lignin content, RS, and the microfibril angle (MFA) of the middle layer of the secondary wall (S2 layer) differed among latitudes. The increase in cellulose content and decrease in MFA were correlated with the contractive value of RS, which explained the higher tensile growth stress in stems from high-latitude plantations where higher cellulose content and lower MFA were observed. To reduce processing defects due to tensile growth stress, the factors controlling MFA values and cellulose content must be identified.

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Characterization of eucalyptus clones subject to wind damage

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2017001100002 ◽

2017 ◽

Vol 52 (11) ◽

pp. 969-976

Author(s):

Antônio José Vinha Zanuncio ◽

Amélia Guimarães Carvalho ◽

Angélica de Cassia Oliveira Carneiro ◽

Paulina Valenzuela ◽

William Gacitúa ◽

...

Keyword(s):

Pearson Correlation ◽

Microfibril Angle ◽

Eucalyptus Grandis ◽

Basic Density ◽

Middle Lamella ◽

Growth Stress ◽

Wind Damage ◽

Modulus Of Rupture ◽

Tree Resistance

Abstract: The objective of this work was to test a new methodology to assess the resistance of trees to wind damage and determine the characteristics that increase clone resistance to winds. Tree resistance to breakage, basic density, ultrastructure, anatomy, mechanical properties, and wood growth stress have been evaluated in seven Eucalyptus grandis × Eucalyptus urophylla clones, collected from a region with a high incidence of wind damage. The Pearson correlation coefficient between the tree resistance to breakage and the ratio between the area damaged by the winds and the total planted area was -0.839, showing the efficiency of the methodology adopted and that high breaking strength results in a smaller area affected by wind damage. Trees with a high basic density, cell wall fraction, modulus of elasticity of the middle lamella and fibers, fiber hardness, modulus of rupture, growth stress and low microfibril angle and height and width of the rays showed greater resistance to wind damage. Therefore, the selection of clones with these features may reduce the incidence of damage by winds in Eucalyptus plantations.

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