J. Liu, X. M. Diao, T. Furuno
Quantitative Analyses of Morphological Variation of Cross-Sectional Tracheids of Hinoki (Chamaecyparis obtusa Endl.) Near Knot by Image
Processing
Summary
Eight transverse sections of hinoki (Chamaecyparis obtusa Endl.) were analyzed along the grain near a
knot by circularity index (CI), aspect ratio and equivalent diameter. The specimens were divided into
two groups, one above and one below the knot, and their distances from the knot were 0 mm (the
nearest), 12 mm, 24 mm, and 36 mm, respectively. Another sample was also selected from knot-free
wood for reference along the same grain. A gradual decrease in the aspect ratio of tracheids demonstrated
that both boundaries and lumina tended to have small differences in length and width as they
approached the knot along the grain. CIs of lumina nearest to the knot indicated astonishingly high
values with a narrow range from hexagon to ellipse, compared with the others ranging from rectangle,
via hexagon, to ellipse. In other words, lumina showed a tendency to become round near the knot. In
addition, the equivalent diameters of lumina tended to decrease when approaching the knot, implying
that cell wall thickening of tracheids occur near the knot. It should be noted that the above variations in
tracheids accompanied changes in grain orientation and annual ring width, especially the sharp
transformation nearest to the knot.
Holzforschung, Walter de Gruyter
Print ISSN: 0018-3830
Volume: 56, 04/2002
Pages: 239 - 243
Show full article (external site)
Show all available items of this journal
Search
