Morphological and chemical differentiation between Tunisian populations of Pinus halepensis Mill., Pinus brutia Ten. and Pinus pinaster Ait.

The lipid fraction of seeds from different pine species and populations was studied regarding total lipid content , fatty acid profile and vitamin E composition. The investigated seeds contained a high percentage of lipid (13.6 to 31.5%). L ipid fractions were found to be rich in vitamin E, which varied significantly among species and populations. P. halepensis (Ph-Hn) showed the highest content of vitamin E (256.3 mg/kg of seeds) and the uppermost content of α -tocopherol (44 mg/kg). However, P. halepensis (Ph-Kas) was the richest in γ -tocopherol (204.9 mg/kg). Lipid fractions had a low content of δ -tocopherol (1.2 to 3.6 mg/kg. The highest content of γ -tocotrienol (~18%) was determined for P. halepensis (Ph-Dc and Ph-Hn). Thirteen fatty acids were identified by GC-FID with significant variation between the investigated species. The linoleic acid was the major fatty acid followed by oleic acid and palmitic acid. The chemical differentiation among species for the composition of fatty acids and vitamin E was confirmed by PCA. Significant correlations were observed between the content of vitamin E and fatty acids and ecological parameters of P. halepensis populations.