• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: fatty acids; secondary xylem; senescence; triacyl- glycerols; wood; Northern Finland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.622.890; http://treephys.oxfordjournals.org/content/22/9/661.full.pdf

Summary Variations in the concentration and composition of triacylglycerols, free fatty acids and phospholipids were an-alyzed in Scots pine (Pinus sylvestris L.) trees at five sites. Disks were taken at breast height or at a height of 4 m from the stems of 81 trees differing in diameter and growth rate. The mean concentration of triacylglycerols in sapwood was 26 mg g–1 dry mass; however, variation among trees was large (16–51 mg gdm–1). The concentration of triacylglycerols was slightly larger at 4 m height in the stem than at breast height. Concentrations of triacylglycerols did not differ between the sapwood of young and small-diameter stems (DBH < 12 cm) and the sapwood of old stems (DBH> 36 cm). Concentrations of free fatty acids were negligible in the outer sapwood, but ranged between 5 and 18 mg gdm–1 in the heartwood. The most abundant fatty acids of triacylglycerols were oleic (18:1), linoleic (18:2ω6, 18:2∆5,9), linolenic (pinolenic, 18:3∆5,9,12 and 18:3ω3) and eicosatrienoic acid (20:3∆5,11,14 and 20:3ω6). The concentration of linoleic acid comprised 39– 46 % of the triacylglycerol fatty acids and the concentration was higher in the slow-growing stem from northern Finland than in the stems from southern Finland. Major phospholipids were detected only in sapwood, and only traces of lipid phos-phorus were detected in heartwood.