Introduction: Soil salinity represents one of the most critical abiotic stress factors adversely impacting the growth, development, and productivity of barley (Hordeum vulgare L.), one of the oldest and most economically significant cereal crops worldwide. The continuous expansion of salinity-affected lands poses a major threat to global food security, particularly in arid and semi-arid regions where excessive irrigation further exacerbates soil salinization. In this context, the identification and deployment of salt-tolerant barley genotypes for cultivation in saline environments have become essential strategies for ensuring sustainable agricultural production.

Materials and Methods: The present study was conducted to evaluate the performance of barley genotypes obtained from the International Center for Agricultural Research in the Dry Areas (ICARDA) under saline field conditions, with the objective of identifying promising candidates for breeding programs aimed at enhancing salinity tolerance. A total of 20 barley genotypes were selected from an initial set of 320 accessions previously screened at the Yazd Agricultural Research Center, Iran, during 2018–2020. These genotypes were subsequently compared with local cultivars under field conditions characterized by high salinity at the Zahak Agricultural Research Station in Sistan over two consecutive cropping seasons (2022–2024). The experimental layout followed a randomized complete block design (RCBD) with three replications. Prior to planting in each season, soil samples were collected to assess baseline soil salinity and nutrient status, ensuring uniform salinity levels across experimental plots. Fertilizer applications were administered according to soil test recommendations to maintain optimal nutrient availability. A range of phenological, morphological, and yield-related traits were recorded, including plant height, days to spike emergence, days to physiological maturity, 1000-seed weight, seed yield per plot, biological yield, and harvest index. Data were subjected to analysis of variance (ANOVA) using SAS software, and treatment means were compared via Duncan’s multiple range test at the 1% significance level.

Results and Discussion: The ANOVA results revealed significant effects of year, genotype, and their interaction on the majority of measured traits, highlighting both environmental influence and genetic diversity among the evaluated barley genotypes. Plant height varied considerably, with genotype 74 attaining the greatest height (73.5 cm) and genotype 80 the shortest (59.67 cm). This variation reflects the combined effects of inherent genetic potential and the inhibitory influence of salinity stress on shoot elongation due to osmotic and ionic imbalances. Substantial variation was also observed in days to spike emergence and physiological maturity. Genotype 92 exhibited the longest time to spike emergence (102.83 days), whereas genotype 122 was the earliest. Earliness under saline conditions is advantageous as it allows genotypes to complete their life cycle before salinity stress peaks, thereby mitigating potential yield losses. Significant differences were recorded in 1000-seed weight, a key yield component. Genotype 74 produced the highest 1000-seed weight (38.17 g), while genotype 100 recorded the lowest (33.67 g). Reduced seed weight under saline conditions is commonly attributed to shortened seed-filling periods and accelerated maturation triggered by stress conditions. In terms of seed yield, genotype 96 significantly outperformed all others, achieving yields approximately 28% higher than genotypes 74 and 284. This outstanding performance highlights its potential for development as a salt-tolerant cultivar. Cluster analysis based on drought and salinity tolerance indices grouped the genotypes into three distinct clusters, with the third cluster comprising the highest-yielding genotypes under stress conditions. Correlation analysis revealed highly significant positive relationships among all measured traits at the 1% probability level. Notably, seed yield exhibited strong positive correlations with days to spike emergence (r = 0.755), days to maturity (r = 0.774), and 1000-seed weight (r = 0.791). These findings suggest that these traits can serve as reliable selection criteria in breeding programs targeting salinity tolerance in barley.

Conclusion: This study underscores the importance of utilizing genetic resources for the development of resilient and adaptable barley cultivars suitable for saline environments. The identification of Genotypes 96, 97, and 118 as high-performing and salt-tolerant candidates provides valuable options for enhancing barley production in salinity-affected regions like Sistan. Moreover, the significant genetic diversity observed among the tested genotypes presents promising prospects for the genetic improvement of barley for salinity tolerance through targeted breeding programs.