Salinity is one of the most important environmental factors that influences both yield and quality of crop plants in arid and semi-arid regions of the world. Barley is the most salt-tolerant cereal crop. Barley is grown in Iran and worldwide as an important field crop which uses for animal feeds and human food as well as fermented malt beverages. Due to the ever-inceasing problem of soil and water salinity in the country, improvement of salinity tolerance of field crops needs to be a high priority. In this study, a barley population derived from hybridization between a cultivated and a wild (spontaneum) genotypes obtained after two backcrossing and two selfing generations (BC2F2) was evaluated for salinity tolerance under field conditions. This population consisted of 142 lines and 2 parents were grown under normal and saline conditions in the research farm of Isfahan University of Technology located at Lavark-Najafabad using two independent 12×12 simple lattice design, each replicated twice. Morphological, physiological, phonological and including plant height, 1000 grain weight, number of spikes per plant, spike length, spike weight, grain yield, biological yield, harvest index, Na concentration, K concentration, K/a ratio, hydrogen peroxide content, malondialdehyde content, prolin content were used to assess salinity tolerance. Malt-quality related traits were also assessed using 36 two-rowed lines of the same population and included lema and palea weight, grain protein content, grain starch content, ?-amylase activity, budding percentage and moisture content were assessed. Descriptive statistics results showed a high diversity for all the agronomic traits among the lines. On the other hand. the quality traits had low variation. Result of analysis variance (ANOVA) showed a significant differences among the lines for all the traits. In addition, results of combined-ANOVA indicated the significant effects of salinity stress on the traits studied. Cluster analysis divided the lines into eight groups under normal conditions, while they were divided in the saline conditions into nine groups. ،To establish the most important traits in predicting grain yield, stepwise regression has been carried out and the results showed that number of spike per plant and weight of spike are the most related to grain yield in both environments. A subsequent path analysis showed that number of spike per plant had the main direct effect on grain yield while spike weight had both direct and indirect effect on grain yield. In conclusion, selection based on number of spike per plant improves yield per see, while selection based on spike weight improves both yield as well as other traits. Keywords : barley, salinity stress, malt, yield component, physiological traits, phonological traits, path analysis
