A Proposal for a New Indicator for Expressing the Metabolic Activity of Living Sapwood Ray Parenchyma Cells

IAWA Journal ◽  
1986 ◽  
Vol 7 (1) ◽  
pp. 17-20
Author(s):  
K.C. Yang
Keyword(s):  
Metabolic Activity ◽  
Slenderness Ratio ◽  
Parenchyma Cell ◽  
Reliable Indicator ◽  
Ray Parenchyma Cell ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Elongation Index ◽  
Ray Parenchyma Cells

A more reliable indicator for expressing the metabolic activity of a living sapwood ray parenchyma cell is proposed and is compared with the old nuclear slenderness ratio (NSR) indicator. NSR is defined as the length of the nucleus divided by the width of the nucleus. The new indicator, the nuclear elongation index (NEI), is defined as the length of the nucleus divided by the length of the ray parenchyma cell multiplied by 100. The validity of the NEI and difference of the use of the NSR and NEI are compared and evaluated.

Vertical and Radial Variation of Nuclear Elongation Index of Living Sapwood Ray Parenchyma Cells in a Plantation Tree of Cryptomeria Japonica

IAWA Journal ◽  
1994 ◽  
Vol 15 (3) ◽  
pp. 323-327 ◽  
Author(s):  
K.C. Yang ◽  
Y.S. Chen ◽  
C.A. Benson
Keyword(s):  
Metabolic Activity ◽  
Cryptomeria Japonica ◽  
Ground Level ◽  
Tree Crown ◽  
Growth Rings ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Cells ◽  
Elongation Index ◽  
Ray Parenchyma Cells

Vertical and radial variations of nuclear elongation index (NEI) of living sapwood ray parenchyrna cells were studied in a 45-year-old plantation tree of Cryptomeria japonica D. Don collected in Taiwan on February 27, 1992. Nine wood strips oriented in an E-W direction of the tree were collected starting at 0.3 m above ground level, and progressing upwards by 2.5 m intervals to the tree crown. Radial sections, 20 µm thick, were cut from the cambium toward the inner sapwood of these nine wood strips. The nuclear elongation index (NEI) was used to express the metabolic activity of the ray cells. It was found that metabolic activity of sapwood ray parenchyma was thc highest at the outer sapwood and declined gradually towards the inner sapwood. The lowest average NEI was found at the lowest stern level. The average NEI of various stern height levels increased with increasing stern height level. The average NEI of three growth rings at the outer sapwood near the cambium reached a maximum at the bottom of the live crown.

Wound Effects on Xylem Cell Differentiation in a Conifer

IAWA Journal ◽  
1984 ◽  
Vol 5 (4) ◽  
pp. 295-305 ◽  
Author(s):  
Keiko Kuroda ◽  
Ken Shimaji
Keyword(s):  
Cell Differentiation ◽  
Loblolly Pine ◽  
Parenchyma Cell ◽  
Cell Maturation ◽  
Bordered Pit ◽  
Xylem Cell ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Cambial Zone ◽  
Ray Parenchyma Cells

Modified xylem cells formed around a minute injury due to pin insertion in the cambium of loblolly pine stern were observed periodically in order to study the mechanism of xylem cell differentiation in conifers. Ray parenchyma cells in the mature xylem as well as in the cambial zone were strongly activated. They not only proliferated randomly in the wound gap, but also invaded into some mature tracheids through the pinoid pits to form tylosis-like structures. Then they reticulately thickened and lignified their wall much earlier and more excessively than the normal ray parenchyma cells. Immature ray tracheids, which also divided several times abnormally in the cambial zone, differentiated into ray tracheids without differentiating into any other elements, although some of them had modified pits. Immature axial tracheids near the injury differentiated normally even though some sporadic transverse or radial division occurred before maturation. Only exceptionally, some peculiar groups of small bordered pit pairs were formed between them. It was clear that a shift from differentiating direction on the way of cell maturation, for instance from immature tracheid to parenchyma cell, was never induced by injury. Cambial initials, both ray and fusiform, were very stable.

Nuclear Changes in the Ageing Ray Parenchyma Cells in Relation to Heartwood Formation

IAWA Journal ◽  
1983 ◽  
Vol 4 (4) ◽  
pp. 265-271 ◽  
Author(s):  
M.N.B. Nair ◽  
R.R. Chavan
Keyword(s):  
Slenderness Ratio ◽  
Nuclear Area ◽  
Strong Negative Correlation ◽  
Lagerstroemia Speciosa ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Nuclear Changes ◽  
Definite Pattern ◽  
Ray Parenchyma Cells ◽  
Acacia Catechu

Nuclear changes occurring in the ray parenchyma cells of the wood in six tropical taxa have been studied with the aid of standard statistical methods. In the taxa with distinct heartwood (Acacia catechu, Bauhinia tomentosa, Bridelia retusa, Lagerstroemia speciosa), the nuclear area and slenderness ratio show a strong negative correlation with the distance from the cambium except in Lagerstroemia speciosa, where the slenderness ratio shows no relation. In Bauhinia purpurea and Lagerstroemia indica, having no distinct heartwood, the nuclear area and slenderness ratio bear no relation with the distance from the cambium, except for the slenderness ratio in Lagerstroemia indica which shows a positive correlation. The analysis indicates that the change in the nuclear area and slenderness ratio shows a definite pattern during the necrobiosis of the ray parenchyma cells in the taxa where heartwood is distinct.

Tyloses in Abscission Scars of Loblolly Pinel

IAWA Journal ◽  
1999 ◽  
Vol 20 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Roland R. Roland R.Dute ◽  
Kathy M. Duncan ◽  
Brandon Duke
Keyword(s):  
Pinus Taeda ◽  
Parenchyma Cell ◽  
Type Ii Cells ◽  
Type Ii ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells

During a study of fascicle abscission in Pinus taeda L., tyloses were observed to occlude tracheids of both proximal and distal abscission scars. The tyloses represent the protrusion of ray parenchyma cells into tracheid lumens. Multiple tyloses often arise from a given parenchyma cell and can enter multiple tracheids. Tyloses occur as part of an abscission process that also includes the presence of Type II cells (programmed to enlarge during abscission in the presence of ethylene) and rupture of tracheids-features common to abscission in angiosperms.

Ray Structure Differences between Rootwood and Stemwood in a Range of Softwood Species

IAWA Journal ◽  
2009 ◽  
Vol 30 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Pat Denne ◽  
Siân Turner
Keyword(s):  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Structural Differences ◽  
Ray Parenchyma Cells ◽  
Practical Implications ◽  
Softwood Species

Differences between the ray structure of rootwood and stemwood were analysed in 11 species from 5 families of gymnosperms. Rootwood was consistently found to have fewer ray tracheids, with ray parenchyma cells which were taller axially, wider tangentially, but shorter radially, and had more pits per cross-field than stemwood. A scale for quantifying types of cross-field pitting is proposed, and statistically significant differences in type and diameter of cross-field pitting were found between rootwood and stemwood of most species sampled. These structural differences have practical implications for identification of gymnosperm roots, and for distinguishing between rootwood and stemwood.

Ray Structure in Root- and Stem-Wood of Larix Decidua: Implications for Root Identification and Function

IAWA Journal ◽  
2008 ◽  
Vol 29 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Pat Denne ◽  
Peter Gasson
Keyword(s):  
Wood Anatomy ◽  
Larix Decidua ◽  
Stem Wood ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells ◽  
And Function

Differences in ray structure between root- and stem-wood of softwoods can cause confusion in identifying roots using keys based on stem-wood anatomy. Comparison of root- and stem-wood rays of Larix decidua showed root-wood had fewer ray tracheids, taller, wider but shorter ray parenchyma cells, and larger cross-field pits than stem-wood. The implications of these differences are considered in relation to the identification and function of roots.

INHIBITION OF WATER CONDUCTIVITY CAUSED BY WATERMARK DISEASE IN SALIX SACHALINENSIS

IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Yasuaki Sakamoto ◽  
Yuzou Sano
Keyword(s):  
Wood Anatomy ◽  
High Moisture ◽  
Water Conductivity ◽  
X Ray ◽  
Salix Sachalinensis ◽  
Water Conduction ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
High Moisture Level ◽  
Ray Parenchyma Cells

Water conduction and wood anatomy of Salix sachalinensis attacked by watermark disease were investigated. The internal symptom, the watermark, appeared as a brown to brown-black stained zone in sapwood. Dye injection tests revealed that water conduction did not take place in the watermark. However, soft X-ray photography and cryo-scanning electron microscopy revealed that the watermark had a high moisture level. In the watermark, some of the vessels were plugged with tyloses and masses of bacteria, and some of the ray parenchyma cells caused necrosis. Hence, the non-conductive watermark in sapwood can be considered similar to discoloured wood or wetwood.

The fine structure of the pits of Eucalyptus regnans (F. Muell.) and their relation to the movement of liquids into the wood

1960 ◽  
Vol 8 (1) ◽  
pp. 51 ◽  
Author(s):  
J Cronshaw
Keyword(s):  
Secondary Wall ◽  
Structural Features ◽  
Cellulose Microfibrils ◽  
Primary Wall ◽  
Detailed Structure ◽  
Eucalyptus Regnans ◽  
Pit Membrane ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells

Observstion in the electron microscope of carbon replicas of the pits of vessels, ray parenchyma cells, fibres, and tracheids of Eucalyptus regnans has shown the detailed structure of the pit borders and the pit closing membranes. In all cases in the mature wood the primary wall is left apparently without modification as the pit membrane. Unlike the borders of the pits of fibre tracheids and tracheids, the pit borders of the vessels are not separate; the cellulose microfibrils of a border may be common to several pits. The pit borders of fibre traoheids and tracheids are developed as separate entities and have a structure similar to the pit borders of softwood tracheids. The structure of the secondary wall layers associated with the pits is described and related to the structure of the pits. The fine structural features of the pits, especially of the pit closing membranes, are discussed in relation to the movement of liquids into wood.

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