Genetic assessment of durum wheat under salinity stress: agronomic and physiological insights for salt tolerance breeding

Developing salt-tolerant genotypes is an important approach for sustaining crop productivity in saline environments. In durum wheat (Triticum turgidum ssp. Durum), exploiting genetic variability through hybridization can enhance the selection of traits associated with salt tolerance. In this study, a half-diallel cross involving six parental genotypes was evaluated under saline conditions (100 mM NaCl) to investigate the inheritance of key agronomic and physiological traits, including chlorophyll content, potential photochemical efficiency of photosystem II (Fv/Fm), ionic selectivity, thousand kernel weight, and heading time. The study was carried out using a complete block design that was randomized, with three rounds of testing. The analysis of the data was performed using Griffing’s Method 2 and Model 1, allowing the estimation of general and specific combining abilities. Significant genetic variation was observed among genotypes, with additive gene effects predominating for chlorophyll content, Fv/Fm, and ionic selectivity. These traits also exhibited relatively high narrow-sense heritability, with values of 63.31% for chlorophyll content and 62.09% for Fv/Fm. Among the parental lines, the landrace Badri showed favorable general combining ability for both chlorophyll content and Fv/Fm, indicating strong potential for improving photosynthetic performance under salt stress. The cultivar Mâali also demonstrated desirable combining ability, particularly for photosynthetic efficiency and grain-related traits. Overall, the results suggest that physiological traits such as chlorophyll content, PSII efficiency, and ionic selectivity can serve as reliable selection criteria, and that the use of adapted landraces in breeding programs represents an effective strategy for enhancing salt tolerance in durum wheat.