Assessment of lipid variability in Globularia alypum L. across diverse climatic regions

This study aimed to evaluate the influence of climatic conditions on the fatty acid composition of Globularia alypum L. Whole plants were collected from six natural populations representing different bioclimatic regions of Tunisia. Total lipids were extracted using a chloroform/methanol mixture according to the Folch method, converted into fatty acid methyl esters (FAMEs), and analysed by gas chromatography with flame ionisation detection (GC-FID). The obtained data were subjected to analysis of variance and Principal Component Analysis (PCA). Eight fatty acids were identified: lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, and arachidic acids. Significant differences (p < 0.05) were observed among populations. Linolenic acid was the predominant unsaturated fatty acid in mst localities, reaching its highest levels in Seliana (30.98%) and Sbikha (29.38%), while the lowest content was recorded in Hafouz (18.51%). Among saturated fatty acids, stearic acid exhibited the greatest variability, with an exceptionally high proportion in Bouchebka (25.70%). PCA clearly discriminated the six populations according to their fatty acid profiles, highlighting the influence of climatic conditions on lipid composition. These findings demonstrate substantial intraspecific variability in the fatty acid composition of G. alypum and suggest that environmental factors play an important role in determining its lipid profile.