Reaction Wood Anatomy in a Vessel-Less Angiosperm Sarcandra Glabra

IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Haruna Aiso ◽  
Futoshi Ishiguri ◽  
Yuya Takashima ◽  
Kazuya Iizuka ◽  
Shinso Yokota

Anatomy and lignin distribution in artificially inclined stems of Sarcandra glabra were investigated to clarify the characteristics of reaction wood (RW) in a vessel-less angiosperm species. Of the five coppiced stems studied from a single tree, two stems were fixed straight and classified as normal wood (NW) and the remaining three stems were inclined at 50 degrees from the vertical to induce the formation of the RW. Compared with NW, the lower side of the inclined samples had a relatively high compressive surface-released strain and an increase in the microfibril angle of the S2 layer of tracheids. However, no significant change was observed in the length or cell wall thickness of the tracheids. The results of Wiesner and Mäule colour reactions indicated that the amount of guaiacyl lignin in the cell walls of tracheids was increased in RW. It appears that RW in Sarcandra is formed on the lower side of inclined stems, and its anatomical characteristics and chemical composition are similar to those of the compression wood (CW) found in gymnosperm species (the so-called “CW-like RW” type).

IAWA Journal ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Haruna Aiso ◽  
Tokiko Hiraiwa ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
...  

Anatomical characteristics and lignin distribution of ‘compression-wood-like reaction wood’ in Gardenia jasminoides Ellis were investigated. Two coppiced stems of a tree were artificially inclined to form reaction wood (RW). One stem of the same tree was fixed straight as a control, and referred to as normal wood (NW). Excessive positive values of surface-released strain were measured on the underside of RW stems. Anatomical characteristics of xylem formed on the underside of RW and in NW stems were also observed. The xylem formed on the underside exhibited a lack of S3 layer in the secondary fibre walls, an increase of pit aperture angle in the S2 layer, and an increase in lignin content. Some of the anatomical characteristics observed in the underside xylem resembled compression wood in gymnosperms. These results suggest that the increase of microfibril angle in the secondary wall and an increase in lignin content in angiosperms might be common phenomena resembling compression wood of gymnosperms.


IAWA Journal ◽  
2004 ◽  
Vol 25 (4) ◽  
pp. 415-423 ◽  
Author(s):  
Jonas Brändström

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.


Holzforschung ◽  
2020 ◽  
Vol 74 (5) ◽  
pp. 459-467 ◽  
Author(s):  
Hui Peng ◽  
Lennart Salmén ◽  
Jiali Jiang ◽  
Jianxiong Lu

AbstractTo achieve efficient utilization of compression wood (CW), a deeper insight into the molecular interactions is necessary. In particular, the role of lignin in the wood needs to be better understood, especially concerning how lignin contributes to its mechanical properties. For this reason, the properties of CW and normal wood (NW) from Chinese fir (Cunninghamia lanceolata) have been studied on a molecular scale by means of polarized Fourier transform infrared (FTIR) spectroscopy, under both static and dynamic loading conditions. Under static tensile loading, only molecular deformations of cellulose were observed in both CW and NW. No participation of lignin could be detected. In relation to the macroscopic strain, the molecular deformation of the cellulose C-O-C bond was greater in NW than in CW as a reflection of the higher microfibril angle and the lower load taken up by CW. Under dynamic deformation, a larger contribution of the lignin to stress transfer was detected in CW; the molecular deformation of the lignin being highly related to the amplitude of the applied stress. Correlation analysis indicated that there was a direct coupling between lignin and cellulose in CW, but there was no evidence of such a direct coupling in NW.


Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Nobuo Yoshizawa ◽  
Hiromi Ohba ◽  
Junko Uchiyama ◽  
Shinso Yokota

Summary The deposition process of lignins within differentiating xylem walls of normal and compression wood of Buxus microphylla var. insularis Nakai was examined by visible-light microspectrophotometry coupled with the Wiesner and Mäule reactions. Buxus formed compression wood on the underside of the leaning stems. The secondary walls of the vessels and fibre tracheids in compression wood showed an intense lignification in the outer region of S2 layer. The spectra of tissues after Mäule and Wiesner reactions showed absorption maxima of around 515 nm and 570 nm, respectively. In differentiating xylem cells of normal wood, lignin composed of both guaiacyl and syringyl units was deposited mainly during the S2 thickening and after formation of the S3 layer in fibre tracheids, whereas in vessels it was actively deposited mainly during the S2 thickening. In compression wood, the deposition of the lignin composed of guaiacyl units was observed for a long period from the early stages of the S2 thickening. Lignification was becoming particularly active at the outer portion of S2 layer after completion of the S2 thickening in both vessels and fibre tracheids. On the other hand, the syringyl units were deposited mainly during the S2 thickening in both cell types.


2016 ◽  
Vol 22 (2) ◽  
pp. 361-367 ◽  
Author(s):  
Aleksandar Savić ◽  
Aleksandra Mitrović ◽  
Lloyd Donaldson ◽  
Jasna Simonović Radosavljević ◽  
Jelena Bogdanović Pristov ◽  
...  

AbstractFluorescence-detected linear dichroism (FDLD) microscopy provides observation of structural order in a microscopic sample and its expression in numerical terms, enabling both quantitative and qualitative comparison among different samples. We applied FDLD microscopy to compare the distribution and alignment of cellulose fibrils in cell walls of compression wood (CW) and normal wood (NW) on stem cross-sections of juvenile Picea omorika trees. Our data indicate a decrease in cellulose fibril order in CW compared with NW. Radial and tangential walls differ considerably in both NW and CW. In radial walls, cellulose fibril order shows a gradual decrease from NW to severe CW, in line with the increase in CW severity. This indicates that FDLD analysis of cellulose fibril order in radial cell walls is a valuable method for estimation of CW severity.


1952 ◽  
Vol 5 (4) ◽  
pp. 385 ◽  
Author(s):  
ABW Ardrop ◽  
HE Dadswell

Cell division, the nature of extra-cambial readjustment, and the development of the secondary wall in the tracheids of conifer stems have been investigated in both compression wood and normal wood. It has been shown that the reduction in tracheid length, accompanying the development of compression wood and, in normal wood, increased radial growth after suppression, result from an increase in the number of anticlinal divisions in the cambium. From observations of bifurcated and otherwise distorted cell tips in mature tracheids, of small but distinct terminal canals connecting the lumen to the primary wall in the tips of mature tracheids, and of the presence of only primary wall at the tips of partly differentiated tracheids, and from the failure to observe remnants of the parent primary walls at the ends of differentiating tracheids, it has been concluded that extra-cambial readjustment of developing cells proceeds by tip or intrusive growth. It has been further concluded that the development of the secondary wall is progressive towards the cell tips, on the bases of direct observation of secondary wall formation in developing tracheids and of the increase found in the number of turns of the micellar helix per cell with increasing cell length. The significance of this in relation to the submicroscopic organization of the cell wall has been discussed. Results of X-ray examinations and of measurements of� tracheid length in successive narrow tangential zones from the cambium into the xylem have indicated that secondary wall formation begins before the dimensional changes of differentiation are complete.


Holzforschung ◽  
2020 ◽  
Vol 74 (8) ◽  
pp. 789-797
Author(s):  
Shuoye Chen ◽  
Miyuki Matsuo-Ueda ◽  
Masato Yoshida ◽  
Hiroyuki Yamamoto

AbstractTo understand the irreversible dimensional changes caused by hygrothermal treatment of green wood, i.e. hygrothermal recovery (HTR), green hinoki compression wood (CW) and normal wood (NW) were hygrothermally (HT) treated in water at 100°C for 120 min and their HTR strains were determined. The specimens were then swollen using dimethyl sulfoxide (DMSO) and then completely dried after solvent exchange with water at room temperature. Their HTR strains were then compared with their DMSO swelling and drying shrinkage strains. The volumetric HTR strains in the CW were about twice as large as those in the NW. Moreover, the microfibril angle (MFA) was found to be an important factor for controlling the HTR intensity. A clear commonality between the HTR behavior and both DMSO swelling and drying shrinkage behavior was identified, which indicates that HTR is caused by volumetric changes in the matrix substances. HTR has been defined as a phenomenon due to the release of locked-in growth stress when a wood specimen is HT treated. To determine whether DMSO treatment has a similar effect as hygrothermal treatment, both HT-untreated and HT-treated specimens were swollen using DMSO, and their dimensional changes during and after DMSO treatment were compared. The results showed that DMSO treatment is a possible alternative for releasing the locked-in growth stress.


IAWA Journal ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 372-382 ◽  
Author(s):  
H. Aiso ◽  
F. Ishiguri ◽  
T. Ohkubo ◽  
S. Yokota

The objective of this study is to clarify the anatomical characteristics and lignin distribution of reaction wood in a vessel-less angiosperm species, Tetracentron sinense Oliv. Sample disks (1 cm in thickness) were collected from three different positions of a Tetracentron sinense tree. Cell morphologies, the microfibril angle (MFA) in the S2 layer, lignin distribution, and lignin content were measured. There was neither a gelatinous (G-)layer nor an S3 layer on the upper side of inclined samples. However, the secondary wall of the normal tracheids was only weakly stained by Mäule and phloroglucinol-HCl. MFA in the S2 layer and lignin content decreased on the upper side of inclined samples. This qualifies the reaction wood of Tetracentron as “tension wood-like”. The so-called “unusual tracheids”, typical for the wood of Tetracentron, showed weaker changes in their anatomical and chemical characteristics in reaction wood than normal tracheids, indicating their special function in water transport. It is hypothesized that vessel-less angiosperms rich in syringyl units in their lignin, produce tension wood-like reaction wood on the upper side of inclined stems or branches, with lower MFA and lignin content in their normal tracheid walls, irrespective of whether a typical G-layer is formed or not.


IAWA Journal ◽  
2004 ◽  
Vol 25 (3) ◽  
pp. 253-271 ◽  
Author(s):  
Lloyd A. Donaldson ◽  
Jenny Grace ◽  
Geoff M. Downes

Two trees of radiata pine, one showing severe lean, the other growing almost vertically, were assessed for the presence and anatomical properties of compression wood, including anatomy, lignin distribution, microfibril angle, basic density, radial and tangential lumen diameter and cell wall thickness. Both trees contained significant amounts of compression wood although the severity and amount of compression wood was greater in the leaning tree. Changes in lignin distribution seem to be characteristic of the mildest forms of compression wood with reduced lignification of the middle lamella representing the earliest change observed from normal wood. An increase in microfibril angle was associated with both mild and severe compression wood although examples of severe compression wood with the same or smaller microfibril angles than opposite wood, or with very small microfibril angles, were found. When segregated into mild and severe compression wood the average difference in microfibril angle was 4° and 8° respectively compared with opposite wood. Within-ring distribution of microfibril angle was different in severe compression wood compared to opposite wood with higher angles in the latewood.Severe compression wood showed a 22% increase in basic density compared to mild compression wood and opposite wood. The increased density was accounted for in terms of a 26% increase in tracheid wall thickness throughout the growth ring, offset by a 9% increase in radial lumen diameter, slightly greater in the latewood. There were no significant changes in density or cell dimensions in mild compression wood compared with opposite wood.


Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Asghar Tarmian ◽  
Patrick Perré

Abstract The air permeability in longitudinal and radial directions of compression wood in spruce (Picea abies) and tension wood in beech (Fagus sylvatica) was compared with that of the corresponding normal wood. The primary aim of the present study was to explain why the reaction woods dry more slowly than the normal woods in the domain of free water. A number of boards conventionally dried to an average final moisture content of 12% were chosen to perform the measurements. Bordered pits on the radial walls of longitudinal tracheids in the compression and normal wood and intervessel or intervascular pits in the tension and normal wood were also examined. The reaction wood of both species is less permeable than the normal wood, both in longitudinal and radial directions. The difference in permeability was more pronounced between compression and normal wood of spruce, especially in longitudinal direction. From an anatomical point of view, this is likely related to some differences in anatomical characteristics affecting the airflow paths, such as the pit features. Such results can explain the difference in drying kinetics of the reaction and normal woods in the capillary regime of drying.


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