Fig. 5

Light micrographs (a, b, e, h, k), inverted gray-scale images of panels b, e, h, k (c, f, i, l) and gray-level profiles of cell walls (d, g, j, m) of transverse sections at the boundary between whitish and black regions in samples of D. kaki wood. Representative gray-level profiles in d, g, j, m were obtained from the yellow-lined sites in the gray-scale images c, f, i, l, respectively. Asterisks in b, c show higher-magnification images of a pit region (the enclosed area). White arrowheads indicate deposits of colored substances on the inner surfaces of wood fibers in pit regions. AP: axial parenchyma cell; CML: compound middle lamella; L: lumen; RP: ray parenchyma cell; SW: secondary wall; F: wood fiber. Scale bars = 100 μm in a; 50 μm in b, c, e, f, h, i, k, l; 5 μm in enclosed area of b, c