title: Structural variation of tracheids in Norway spruce (Picea abies [L.] Karst.).
abstract: The orientation of cellulose microfibrils in the cell wall and the shape and the dimensions of the cells of earlywood of four Norway spruce (Picea abies [L.] Karst.) stems grown in Finland were studied by X-ray diffraction and optical microscopy. The average microfibril angle (MFA) decreased and the diameter of the cell increased rapidly up to rings 5-10 from the pith and remained at the same level after that. The average MFA close to the pith was over 20 degrees and decreased to about 8 degrees after ring 10 from the pith. The average diameter of the cells was 35 microm in the outer rings. The shape of the cross section of the lumen changed from circular to rectangular from the pith to the bark. The tracheid length increased also as a function of the distance from the pith. The thickness of the cell wall varied between 2.8 and 3.5 microm. Automatic cell lumen and cell wall recognition procedures were developed for the analysis of the images of the cross sections of the cells.
authors.affiliation: Department of Physics, University of Helsinki, Finland
authors.forename: M P
authors.initials: MP
authors.lastname: Sarén
authors.forename: R
authors.initials: R
authors.lastname: Serimaa
authors.forename: S
authors.initials: S
authors.lastname: Andersson
authors.forename: T
authors.initials: T
authors.lastname: Paakkari
authors.forename: P
authors.initials: P
authors.lastname: Saranpää
authors.forename: E
authors.initials: E
authors.lastname: Pesonen
mesh_terms: D002473:Cell Wall / Q000648:ultrastructure; D002482:Cellulose / Q000648:ultrastructure; D020894:Microfibrils / Q000648:ultrastructure; D028222:Picea / Q000033:anatomy & histology*; D018514:Plant Structures / Q000033:anatomy & histology*; D014961:X-Ray Diffraction
chemical_list: D002482:Cellulose