Background Salinity is one of the major limiting abiotic stresses that decrease crop production worldwide. To recommend genotypes for cultivation under saline stress conditions, a comprehensive understanding of the genetic basis and plant responses to this stress is needed. In the present study, a total of 20 barley genotypes were investigated to identify potential salt-tolerant genotypes, both at the early growth stage using a hydroponic system, and in adult plants under field conditions. For these purposes, the multi-trait genotype-ideotype distance index (MGIDI) was used to identify salt-tolerant barley genotypes at the seedling stage, and the weighted average of absolute scores (WAASB) index was used to identify the high-yielding and stable genotypes in adult plant stage. At the early growth stage, barley seedlings were treated with two salinity levels: 0 mM NaCl (as control conditions) and 200 mM NaCl (as stress conditions) for 30 days, and during this period different growth and physiological traits were measured. Besides, the yield performance and stability of the investigated barley genotypes were evaluated across five environments during the 2018–2020 cropping seasons. Results Salinity stress significantly decreased growth and physiological traits in all seedling plants; however, some salt-tolerant genotypes showed minimal reduction in the measured traits. Multivariate analysis grouped the measured traits and genotypes into different clusters. In the early growth stage, the G12, G14, G6, G7, and G16 were selected as the most salt-tolerant genotypes using MGIDI index. In the multi-environment trials experiment, AMMI analysis showed that grain yields of the tested barley genotypes were influenced by the environment (E), genotype (G), and GE interaction. Based on the weighted average of absolute scores of the genotype index (WAASB) and other stability statistics, G7, G8, G14, and G16 were selected as superior genotypes. Conclusion Together the MGIDI and WAASB indices revealed that three genotypes—G7, G14 and G16—can be recommended as new genetic resources for improving and stabilizing grain yield in barley programs for the moderate climate and saline regions of Iran. Our results suggest that using the MGIDI index in the early growth stage can accelerate screening nurseries in barley breeding programs. Besides, the WAASB index can be used as a useful stability measurement for identify high-yielding and stable genotypes in multi-environment trials.

The salinity tolerance of 17 breeding wheat genotypes along with three local varieties was evaluated under control and salinity stress (160 mM NaCl) conditions. At the seedling stage, shoot and root dry weights, relative water content (RWC), membrane stability index (MSI), relative chlorophyll content (SPAD index), root and shoot Na + (RN and SN), root and shoot K + (RK and SK), root and shoot K + /Na + ratios (RKN and SKN), root-to-shoot Na + translocation (RTSN), root-to-shoot K + translocation (RTSK), stomatal conductance (G S ), transpiration rate (T E ), and photosynthesis rate (P N ) were measured. Moreover, the investigated genotypes were assessed in terms of grain yield across four saline regions during the 2018-2019 cropping seasons. Salinity stress caused a signi cant reduction in the RDW, SDW, PN, G S , T E , SK, RKN, SKN, RTSN, and RTSK, but resulted in increased RN, RK, and SN. The results of AMMI analysis of variance also indicated signi cant differences among test locations, genotypes, and their interaction effects. The PCA-based biplot revealed that grain yield strongly correlated with RKN and RK. Furthermore, the correlation among P N , G S , and T E traits was strong and positive and had a positive correlation with RWC, MSI, RDW, and SPAD index. Considering our results, RK and RKN were identi ed as useful physiological tools to screen salt tolerance at the early-growth stage. According to the ranking patterns obtained by the average sum of ranks method (ASR) and grain yield, we observed that genotype number G5 had considerable physiological potential at the early-growth stage and also responded well to soil salinity at the farm; thus this genotype can be promoted for commercial production.

Salinity stress is one of the major limiting abiotic stresses that decrease crop production worldwide. To recommend genotypes for cultivation under saline stress conditions, comprehensive understanding of genetic basis and plant responses to this stress is need. In the present study, a total of 20 barley genotypes were investigated to isolate potential salt-tolerant genotypes at the early growth stage using hydroponic system, and adult plant under field conditions. Different growth and physiological traits including root fresh and dry weights (RFW and RDW), shoot fresh and dry weights (SFW and SDW), relative water content (RWC), membrane stability index (MSI), relative chlorophyll content (SPAD index), root and shoot Na+ (RN and SN), root and shoot K+ (RK and SK), root and shoot K+:Na+ ratios (RKN and SKN), root-to-shoot Na+ translocation (RTSN), root-to-shoot K+ translocation (RTSK), stomatal conductance (GS), transpiration rate (TE), and photosynthesis rate (PN) were measured. Barley seedling were treated with two salinity levels (0 mM NaCl (as control conditions) and 200 mM NaCl (as stress conditions)) for 30 days. Moreover, the yield performance and stability of investigated barley genotypes were evaluated across five environments during the 2018–2020 cropping seasons. Salinity stress significantly decreased growth and physiological traits in all seedling plants; however, some salt-tolerant genotypes showed the lowest reduction in measured traits. Multivariate analysis grouped measured traits and tested genotypes into different clusters. The multi-trait genotype–ideotype distance index (MGIDI) selected genotypes G12, G14, G6, G7, and G16 as the salt-tolerant barley genotypes. Considering the results of the AMMI analysis showed that grain yields of tested barley genotypes were influenced by environment (E), genotype (G) and GE interaction effects. Based on the weighted average of absolute scores of the genotype index (WAASB) and other stability statistics, G7, G8, G14, and G16 were selected as superior genotypes. Considering the outputs of MGIDI and WAASB indices revealed that three genotypes G7, G14 and G16 can be recommended as new genetic resources for improving and stabilizing grain yield in barley programs for the moderate climate and saline regions of Iran. In conclusion, our results suggest that the using MGIDI index in the early growth stage can accelerate screening nurseries in barley breeding programs.

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