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Barley (Hordeum vulgare L.) is an important crop in Tunisia, especially in the south, which is characterized by an arid Saharan climate. Water resources, when available, are saline. In this study, 26 barley genotypes were evaluated in Saharan conditions. Plants were irrigated with saline water. Germination percentage, height, leaf area, tiller number, percentage of senescing leaves, leaf chlorophyll content, shoot dry weight and grain yield varied significantly between genotypes. This implies that important intraspecific genetic variation in this germplasm exists in response to salinity and aridity. The estimated grain yield of the introduced cultivar ‘ 113/1B’ and a local landrace ‘‘reached 1.1 t ha –1 , despite these saline and arid conditions, and exceeded the overall national average yield of about 0.75 t ha –1 . Selection of these genotypes can be profitable when grown in marginal areas using brackish water. The soil electric conductivity did not increase at the experimental location following saline irrigation: 2.30 dS m –1 at sowing and 2.37 dS m –1 at harvest, indicating that there is no risk of salt accumulation in sandy soil.

Two hundred ninety­six Asian barley (Hordeum vulgare L.) accessions were assessed to detect QTLs underlying salt tolerance by association analysis using a 384 single nucleotide polymorphism (SNP) marker system. The experiment was laid out at the seedling stage in a hydroponic solution under control and 250 mM NaCl solution with three replications of four plants each. Salt tolerance was assessed by leaf injury score (LIS) and salt tolerance indices (STIs) of the number of leaves (NL), shoot length (SL), root length (RL), shoot dry weight (SDW) and root dry weight (RDW). LIS was scored from 1 to 5 according to the severity of necrosis and chlorosis observed on leaves. There was a wide variation in salt tolerance among Asian barley accessions. LIS and STI (SDW) were the most suitable traits for screening salt tolerance. Association was estimated between markers and traits to detect QTLs for LIS and STI (SDW). Seven significant QTLs were located on chromosomes 1H (2 QTLs), 2H (2 QTLs), 3H (1 QTL), 4H (1 QTL) and 5H (1 QTL). Five QTLs were asso­ ciated with LIS and 2 QTLs with STI (SDW). Two QTLs associated with LIS were newly identified on chromosomes 3H and 4H.