This brief historical review focuses on durum wheat domestication and breeding in the Mediterranean region. Important milestones in durum wheat breeding programs across the countries of the Mediterranean basin before and after the Green Revolution are discussed. Additionally, the main achievements of the classical breeding methodology are presented using a comparison of old and new cultivars. Furthermore, current breeding goals and challenges are analyzed. An overview of classical breeding methods in combination with current molecular techniques and tools for cultivar development is presented. Important issues of seed quality are outlined, focusing on protein and characteristics that affect human health and are connected with the consumption of wheat end-products.

Bread wheat landraces were an important source of biodiversity used in agriculture before the widespread adoption of high-yielding commercial cultivars adapted to high inputs. Could future agriculture exploit these landraces in different cropping systems in organic or lower-input environments? A two-year field trial was conducted to evaluate grain yield, agronomic performance, and grain quality of bread wheat landraces under different cropping systems, including low-input/organic/conventional environments. Significant variability was found for almost all characteristics among landraces, which makes landraces valuable sources of genetic variation for breeding programs aimed at achieving high and consistent production as well as high-quality products in low-input/organic environments. Additionally, landraces play a crucial role in expanding the genetic diversity of cultivated bread wheat and mitigating biodiversity erosion, thereby enabling crops to better withstand the challenges of low-input/organic agriculture. The landrace “Xilokastro Lamias” had the highest yield among the landraces evaluated in the first growing season (2.65 t·ha⁻¹) and one of the highest yields (2.52 t·ha⁻¹) of all genotypes in the second growing season, which shows promising potential as a starting material in breeding programs targeting high and stable yields. GGE biplot analysis identified the landrace ”Xilokastro Lamias”, along with commercial cultivars “Yecora E” and “Panifor”, as suitable candidates for direct use in low-input/organic wheat farming systems to achieve enhanced productivity. In the conventional environment (C2-IPGRB), commercial cultivars showed the highest values (3.09 to 3.41 ton·ha⁻¹). Of the landraces, only the X4 showed a high GY (3.10 ton·ha⁻¹) while the other landraces had ~33–85% lower yield. In the organic environment (O2-IPGRB), the highest productivity was found in the commercial cultivar X5 and the landrace X4. Commercial cultivars X8 and X7 showed ~68% reduction in GY in the organic environment compared to the conventional, while this reduction was half for the landraces. Finally, the reduction in grain yield between conventional and organic environments was observed to be 45% for commercial cultivars, while it was only half for landraces. This finding confirms the adaptability of landraces to organic agriculture.

Aside from plant breeding and agricultural inputs, understanding and interpreting the Genotype × Environment (G × E) interaction has contributed significantly to the increase in wheat yield. In Central Macedonia, Greece, fifteen commercially important durum wheat cultivars and one landrace were tested in six cultivation environments classified into high- and low- productivity environments. This study aimed to identify the most productive and stable durum wheat genotypes across Mediterranean farming systems through a comparative examination of genotype plus genotype by environment (GGE) biplot alongside fifteen parametric and non-parametric stability models. In the organic (low productivity) environment, cultivar Zoi and the landrace Lemnos showed remarkable results, indicating a potential solution for biological agriculture. For the late-sowing (low productivity) environment, some widespread varieties such as Mexicali-81, Meridiano, and Maestrale had excellent performance, showing potential to overcome more adverse conditions during critical grain filling periods such as higher air temperature and deficient soil moisture, i.e., conditions that correlate with climate change. Evaluation of genotypes in all environments for a combination of high yield and stable production, showed that the best genotypes were G8 (Simeto), G2 (Canavaro), and G12 (Elpida). In the subgroup with the three high-productivity environments, G12 (Elpida), G8 (Simeto), and G6 (Mexicali-81) were the best genotypes, followed by G2 (Canavaro), while in the low-productivity subgroup, the G2 (Canavaro), G13 (Zoi) and G8 (Simeto) genotypes were the best.

This study assessed the variations in grain yield (GY) and protein content (PC) within two commercial durum wheat cultivars (Svevo and Maestrale) and evaluated their responses to intra-cultivar selection for both traits. We investigated whether the variations are exploitable and could result in concurrent GY and PC upgrading. The experiments were conducted in the IPBGR, Thessaloniki, Greece (2018–2020). The first year included two identical honeycomb design trials under ultra-low plant density (ULD) where the divergent selection was applied based on single plant yield and protein content. In the second year, progeny evaluation under typical crop density (TCD) for GY and PC occurred in a randomized complete block (RCB) and with three replications for each cultivar selected line. This revealed considerable variation within already improved commercial cultivars. Single-plant selection for GY and PC simultaneously resulted in: (a) one high-yielding line that significantly outperformed the original cultivar Svevo while maintaining high PC, and (b) two high-grain PC lines that outperformed the original cultivar Maestrale significantly while maintaining high GY. ULD allowed efficient selection for GY and PC simultaneously within narrow gene pools by maximizing phenotypic expression and differentiation among individual plants.