An experimentation using eight Tunisian durum wheat varieties (four landraces and four high yielding ones) was conducted in two different bioclimatic regions (semi-arid and sub-humid) during two growing years. Relationships between agronomic (grain yield), physico-chemical (total protein content, gluten content, gluten index) and molecular parameters (high molecular weight glutenin subunits (HMW-GS), low molecular weight glutenin subunits (LMW-GS) and their ratios) were investigated. The variability of protein content was significant in relation to environment (E), while the gluten index, indicating the gluten strength, was mainly controlled by genotypic factors (G). The quantification in relative percentages of HMW-GS y and x by CE LabChip90 and the estimation of HMW-GSy/HMW-GSx and of HMW-GS/LMW-GS showed that these fractions have varied in relation to E, G and to their interaction (p<0.05). The correlation test showed significant associations between physico-chemical and molecular parameters, whereas these relationships varied significantly in relation to E and G. The Principle Component Analysis (PCA) has distinguished four different quality profiles, where a given variety produced very different qualities in different environments. These results highlight the importance of the evaluation of genotypes under different conditions and suggest that more investigations are requested to optimize the use and the recommendations of varieties.