FTIR-ATR spectral and Chemometric characterization of leaf and seed tissues from wild and domesticated Phaseolus vulgaris.

Wild plant species represent valuable genetic and biochemical resources; however, their compositional variability and macromolecular organization remain insufficiently characterized. In this study, leaf and seed tissues from eight populations of wild Phaseolus vulgaris were analyzed using Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR) combined with chemometric analysis. Distinct spectral profiles were observed between tissues. Seeds exhibited 13 dominant absorption bands and were mainly associated with proteins and storage carbohydrates, while leaves exhibited 11 dominant bands with stronger contributions from lipid-associated signals and structural polysaccharides. Variations in the amide I and II regions reflected differences in protein-associated spectral profiles among populations, while carbohydrate-associated regions reflected variability in polysaccharide-related spectral profiles among populations. Sparse Partial Least Squares-Discriminant Analysis (sPLS-DA) and hierarchical cluster analysis (HCA) revealed differences and similarities among populations according to their spectral profiles, particularly in protein-, lipid- and carbohydrate- associated regions. Overall, the integration of FTIR-ATR spectroscopy and chemometric analysis provided a useful approach for characterizing biochemical variability in wild Phaseolus vulgaris tissues and revealing compositional differences among populations.