Volumetric estimate of bordered pits in Pinus sylvestris based on X-ray tomography and light microscopy imaging

• Published in: Micron (Oxford, England : 1993) Vol. 124; p. 102704
• Main Authors: Koddenberg, Tim, Wentzel, Maximilian, Militz, Holger
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2019
• Subjects: Bordered pit; Image analysis; Imaging, Three-Dimensional; Microscopy; Models, Theoretical; Pinus sylvestris - ultrastructure; Pit volume; Three-dimensional imaging; Transmission light microscopy; Wood - analysis; Wood - ultrastructure; X-ray micro-computed tomography; X-Ray Microtomography; Pit volume; Image analysis; Bordered pit; Transmission light microscopy; X-ray micro-computed tomography; Three-dimensional imaging
• ISSN: 0968-4328; 1878-4291
• DOI: 10.1016/j.micron.2019.102704

•X-ray tomography and light microscopy images were used to estimate the pit volumes.•X-ray imaging brings a 3D method with a rapid quantification of pit volumes.•Void imaging revealed various pit morphology the along growth ring in 3D.•For microscopic images, the ellipsoid model and spherical cap model were applied.•The ellipsoid model pointed out to be the choice of method for volume estimation. Bordered pits are a major determinant for the hydraulic function of wood tissues. Unlike microscopic imaging (e.g. light and electron microscopy) that is constrained to two-dimensional (2D) information, X-ray micro-computed tomography (XμCT) contributes to three-dimensional (3D) analysis. This advantage was used to estimate the volume of bordered pits in Pinus sylvestris. The 3D data obtained by XμCT were compared with two mathematical models (ellipsoid model and spherical cap model) using 2D data obtained by transmission light microscopy and XμCT. The findings of this study showed that the volume approximation using the ellipsoid model revealed values close to the volumes, which were three-dimensionally obtained by XμCT. This trend, however, is more pronounced for pits in earlywood than in latewood. Nevertheless, this study demonstrated that microscopic images can also be used for the approximation of pit volumes to some extent. Researchers should be aware of limitations that come with the 3D method (e.g. resolution, image analysis) and 2D method (unknown location of the section in the pit) as well as the natural variation of the pit morphology.