Stability analysis of yield component traits in 25 durum wheat (Triticum durum Desf.) genotypes under contrasting irrigation water salinity

• Reduction in grain yield linearly correlated with increased water salinity.
• Yield components for 25 genotypes evaluated, with improved genotype Maali the best.
• Improved genotypes outperform landraces across the range of salinity and aridity.

Stable straw and grain yield constituted a challenging objective for breeders to cope with environmental changes as salinity increase. For this purpose, an assessment of grain yield (GY) and yield components stability of 25 durum wheat genotypes was conducted in three semi-arid sites differing by their irrigation water salinity: Echbika (S1, 6 dS m−1), Barrouta (S2, 12 dS m−1) and Sidi Bouzid (S3, 18 dS m−1) during three growing seasons (2010, 2011 and 2012). A significant average effect (P ≤ 0.05) of sites × genotypes was observed for all measured parameters. GY was the most salinity affected trait showing decrease of 20% in S2, and 50% in S3 compared to control conditions in S1. A significant linear regression exists between GY at control site S1 and GY at saline site S2 (R2 = 0.79; P < 0.001) and saline site S3 (R2 = 0.36; P < 0.001). Improved genotypes overstep landraces for all yield components. As a result, GY is about 30% higher for improved varieties. This trend was inverted for agronomic traits such as plant height, biomass and straw yield (SY). According to stability analysis, only the improved genotype Maali showed stability for GY and SY in the contrasting salinity water irrigation sites. This genotype had a high average GY mean of 0.49 kg/m2 (bi = 1.12; S2d = 0.84) and high SY of 0.70 kg/m2 (bi = 0.85; S2d = 0.42). Our data suggest that improved genotypes could be used under contrasting salinity environment in arid area as well as breeding materials.