Persistence of the gelatinous layer within altered tension-wood fibres of beech degraded by Ustulina deusta

2000 ◽  
Vol 147 (2) ◽  
pp. 347-355 ◽  
Author(s):  
S. BAUM ◽  
F. W. M. R. SCHWARZE ◽  
S. FINK
Keyword(s):  
Tension Wood ◽  
Gelatinous Layer ◽  
Wood Fibres

The nature of reaction wood. IV. Variations in cell wall organization of tension wood fibres

1955 ◽  
Vol 3 (2) ◽  
pp. 177 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Tension Wood ◽  
Secondary Wall ◽  
Degree Of Crystallinity ◽  
Tropical Species ◽  
Normal Wood ◽  
Reaction Wood ◽  
Gelatinous Layer ◽  
Wood Fibres ◽  
Cell Wall Organization

The cell wall organization, the cell wall texture, and the degree of lignification of tension wood fibres have been investigated in a wide variety of temperate and tropical species. Following earlier work describing the cell wall structure of tension wood fibres, two additional types of cell wall organization have been observed. In one of these, the inner thick "gelatinous" layer which is typical of tension wood fibres exists in addition to the normal three-layered structure of the secondary wall; in the other only the outer layer of the secondary wall and the thick gelatinous layer are present. In all the tension wood examined the micellar orientation in the inner gelatinous layer has been shown to be nearly axial and the cellulose of this layer found to be in a highly crystalline state. A general argument is presented as to the meaning of differences in the degree, of crystallinity of cellulose. The high degree of crystallinity of cellulose in tension wood as compared with normal wood is attributed to a greater degree of lateral order in the crystalline regions of tension wood, whereas the paracrystalline phase is similar in both cases. The degree of lignification in tension wood fibres has been shown to be extremely variable. However, where the degree of tension wood development is marked as revealed by the thickness of the gelatinous layer the lack of lignification is also most marked. Severity of tension wood formation and lack of lignification have also been correlated with the incidence of irreversible collapse in tension wood. Such collapse can occur even when no whole fibres are present, e.g. in thin cross sections. Microscopic examination of collapsed samples of tension wood has led to the conclusion that the appearance of collapse in specimens containing tendon wood can often be attributed in part to excessive shrinkage associated with the development of fissures between cells, although true collapse does also occur. Possible explanations of the irreversible shrinkage and collapse of tension wood fibres are advanced.

scholarly journals Precautions for the Structural Analysis of the Gelatinous Layer in Tension Wood

IAWA Journal ◽  
2005 ◽  
Vol 26 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Bruno Clair ◽  
Joseph Gril ◽  
Kei'ichi Baba ◽  
Bernard Thibaut ◽  
Junji Sugiyama
Keyword(s):  
Tension Wood ◽  
Solid Wood ◽  
Mechanical Function ◽  
Serial Sections ◽  
Border Effect ◽  
Anatomical Features ◽  
Living Tree ◽  
Gelatinous Layer ◽  
Embedding Technique ◽  
Wood Fibres

The gelatinous layer (G-layer) of tension wood fibres in hardwood contributes to the mechanical function of the living tree and has significant consequences on properties of solid wood. Its size, shape and structure observed by optical or electron microscopy exhibits characteristic anatomical features. However, we found that sectioning of non-embedded wood samples results in an uncontrolled swelling of the G-layer. In order to assess this artefact, the shape and thickness of the G-layer was monitored by serial sections from an embedded wood sample, from its trimmed transverse face to that located several hundreds of micrometres deep. The results revealed that the initial cutting before embedding produced a border effect responsible for the swollen nature, which is similar to sections from non-embedded material. After a conventional embedding technique was applied, a section of at least 30 micrometres below the trimming surface is required to observe an un-swollen G-layer.

The Possible function of Buttresses in Caryocar Nuciferum (Caryocaraceae) in Guyana: Ecological and Wood Anatomical Observations

IAWA Journal ◽  
1997 ◽  
Vol 18 (4) ◽  
pp. 415-431 ◽  
Author(s):  
Hans ter Steege ◽  
Ben J. H. ter Welle ◽  
Peter B. Laming
Keyword(s):  
Tension Wood ◽  
Microscopic Structure ◽  
Preferential Direction ◽  
Moderate Amount ◽  
Gelatinous Layer ◽  
Structure And Morphology ◽  
Wood Fibres ◽  
Tension Members

This paper describes the microscopic structure and morphology of stern and buttresses of swamp-grown Caryocar nuciferum L. and discusses the function of buttresses. Buttresses are mainly found at the opposite side of the leaning direction of a tree and thus could function as tension members. In contrast to the stern wood, which exhibits a moderate amount of tension wood fibres with a gelatinous layer, the wood of the buttresses on the tension side and the compression side of the leaning tree is characterised by thick-walled tension wood fibres. In addition, the number of vessels in the buttresses is substantially higher than that in the stern wood. The preferential direction of the buttresses and the anatomical differences in the various parts of the tree are discussed.

REACTION TISSUES IN GNETUM GNEMON A PRELIMINARY REPORT

IAWA Journal ◽  
2001 ◽  
Vol 22 (4) ◽  
pp. 401-413 ◽  
Author(s):  
P. B. Tomlinson
Keyword(s):  
Cell Walls ◽  
Tension Wood ◽  
Secondary Xylem ◽  
Secondary Phloem ◽  
Outer Cortex ◽  
Cortical Cells ◽  
Wood Fibres ◽  
Developmental Feature ◽  
Gnetum Gnemon ◽  
Clear Differentiation

Gnetum gnemon exhibits Rouxʼs model of tree architecture, with clear differentiation of orthotropic from plagiotropic axes. All axes have similar anatomy and react to displacement in the same way. Secondary xylem of displaced stems shows little eccentricity of development and no reaction anatomy. In contrast, there is considerable eccentricity in extra-xylary tissue involving both primary and secondary production of apparent tension-wood fibres (gelatinous fibres) of three main kinds. Narrow primary fibres occur concentrically in all axes in the outer cortex as a normal developmental feature. In displaced axes gelatinous fibres are developed abundantly and eccentrically on the topographically upper side, from pre-existing and previously undetermined primary cortical cells. They are wide with lamellate cell walls. In addition narrow secondary phloem fibres are also differentiated abundantly and eccentrically on the upper side of displaced axes. These gelatinous fibres are narrow and without obviously lamellate cell walls. Eccentric gelatinous fibres thus occupy a position that suggests they have the function of tension wood fibres as found in angiosperms. This may be the first report in a gymnosperm of fibres with tension capability. Gnetum gne-mon thus exhibits reaction tissues of unique types, which are neither gymnospermous nor angiospermous. Reaction tissues seem important in maintaining the distinctive architecture of the tree.

Microfibril Angle Distribution of Poplar Tension Wood

IAWA Journal ◽  
2012 ◽  
Vol 33 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Silke Lautner ◽  
Cordt Zollfrank ◽  
Jörg Fromm
Keyword(s):  
Electron Microscopy ◽  
Tension Wood ◽  
Microfibril Angle ◽  
Cellulose Microfibrils ◽  
Normal Wood ◽  
Angle Distribution ◽  
Transmission Electron ◽  
Wood Fibres ◽  
Characteristic Features ◽  
Fibril Angle

Tension wood of poplar (Populus nigra) branches was studied by lightand electron microscopy. The characteristic features of tension wood such as wider growth rings, reduced vessel density and higher gross density were confirmed by our results. Based on a novel combination of transmission electron microscopy (TEM) imaging and image analysis, involving Fourier transformation, the orientation of cellulose microfibrils in the S2- and G-layer was determined. Within the G-layer microfibril angle (MFA) was parallel to the growth axis (0°). However, in the S2 it was 13° in tension wood fibres and 4° in normal wood fibres. With the exception of the relatively low fibril angle in the S2 of tension wood fibres (13°) the results are in good agreement with those of the literature.

scholarly journals Toward identifying molecules responsible for the peculiar properties of the G-layer in tension wood fibres

2011 ◽  
Vol 5 (Suppl 7) ◽  
pp. P121
Author(s):  
Fernanda Guedes ◽  
Miyuki Takeuchi ◽  
Françoise Laurans ◽  
Gilles Pilate
Keyword(s):  
Tension Wood ◽  
Wood Fibres

scholarly journals The Nature of Reaction Wood

1948 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
AB Wardrop ◽  
HE Dads Well
Keyword(s):  
Tensile Strength ◽  
Tension Wood ◽  
Reaction Wood ◽  
Fibre Structure ◽  
Longitudinal Shrinkage ◽  
High Tensile Strength ◽  
Wood Fibres

The structure of tension wood fibres is ofconsiderahle academic and practicalinterest, both in relation to considerations of the stimuli which produce them,and to studies of the influence of fibre structure on the properties of the wood asa whole. As is well known, the chief abnormal properties of tension wood lie inits unusually high longitudinal shrinkage, its high tensile strength, and its lowcompressive strength .

scholarly journals On the detachment of the gelatinous layer in tension wood fiber

2005 ◽  
Vol 51 (3) ◽  
pp. 218-221 ◽  
Author(s):  
Bruno Clair ◽  
Bernard Thibaut ◽  
Junji Sugiyama
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Gelatinous Layer

CHARACTERISTICS OF TROCHODENDRON ARALIOIDES TENSION WOOD FORMED AT DIFFERENT INCLINATION ANGLES

IAWA Journal ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 273-284 ◽  
Author(s):  
Tokiko Hiraiwa ◽  
Tatsuya Toyoizumi ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
...  
Keyword(s):  
Tension Wood ◽  
Growth Promotion ◽  
Growth Stress ◽  
Aperture Angle ◽  
Wall Structure ◽  
Cellulose Content ◽  
Klason Lignin ◽  
Glucose Content ◽  
Gelatinous Layer ◽  
Inclination Angles

To assess the characteristics of tension wood (TW) in Trochodendron aralioides Sieb. et Zucc., seedling stems were artificially inclined at angles of 30° (TW- 30), 50° (TW-50), and 70° (TW-70) from the vertical. At all angles, the growth promotion was pronounced on the upper side of the inclined stems, where excessive tensile growth stress was observed. A gelatinous layer (G-layer) formed in the tracheids of TW. The cell wall structure of the tracheids in TW was S1 + G. The G-layer had a small pit aperture angle <10°. TW-50 showed larger tensile growth stress, a thicker G-layer area, and a smaller pit aperture angle of the Glayer than TW-30 and TW-70. Lower levels of Klason lignin and hemicellulose and higher levels of α-cellulose content were observed in TW-50. In addition, an increase in glucose content and a decrease in xylose content in holocellulose were observed in TW-50. Therefore, it can be concluded that the degree of TW varied with different inclination angles.

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