Wild barley (Hordeum vulgare ssp. spontaneum), which is closely related to cultivated barley and is also the ancestor of barley, provides a rich and suitable source for creating genetic diversity for barley breeding. This species can be easily crossbred with cultivated barley, which can be a suitable and excellent genetic source for improving tolerance to abiotic stress conditions, including salinity. One of the concerns of breeders is how to effectively select high-yielding and stable genotypes, which can be achieved by tolerance and susceptible indices. The aim of the research 1- to eva‎luate the genetic diversity in nested populations (NP) resulting from crosses between barley species and introduction of pure recombinant lines (RIL) with suitable agronomic traits and 2- comparison of new and old tolerance and susceptible indices for the selection of tolerant genotypes to salinity stress. This study was carried out on the population known as IBM-21 included 21 families resulted from crosses between 21 H. spontaneum barley with one cultivated barley Rehan03 in generation BC1F5, which contained a total of 443 recombinant lines. In fact, when different genomes (21 wild) (Foreground) are integrated as donors, in the genetic background of Reihan03 (Background) through backcrosses and self-crossings, each of the donor parents leave a part of their chromosom segments in the recipient parent, which provides a very good diversity for selection of important traits or genetic studies. A number of 443 recombinant lines, along with 4 control cultivars, were eva‎luated under normal conditions and salinity stress (20dS) in the form of augmented design at experimental farm of the Faculty of Agriculture of Isfahan University of Technology during the 1400-1401 growing season. The results showed a high genetic diversity among populations and recombinant lines resulting from crossing wild and cultivated barley, for salinity tolerance and agronomic and phenologic traits. Populations B1R10 and B1R67 with Spontaneum parents from Turkmenistan and Iraq were superior to other populations, respectively. The results of the population comparison showed that nesting and the use of several wild parents to provide diversity to the genetic background of the cultivated variety had different effects in terms of salinity stress tolerance, which indicates the successful transformation of different chromosomal segments from different wild species to the Reihan03 genetic background. The existence of several segregated lines in comparison with wild and cultivated parents for important traits enables the breeder to select tolerant lines or those with desirable agronomic traits, which can provide the basis of new cultivars development. To increase efficiency of selection in the stress environment, univariate and multivariate indices were used. In general, MFVD and SIIG multivariate indices showed effectiveness in grouping and selecting the eva‎luated genotypes. The MFVD index was used to select tolerant genotypes under stress conditions that show the stability of traits. Based on the MFVD index and grain yield in the stress environment, lines 290, 144, 324, 298, 125, 211, 281, 200 and 287 can be selected. SIIG indices (calculated using morphological and yield traits) and CSI (calculated based on a combination of yield indices) were respectively used as a suitable method for selecting stable and high-yielding genotypes. By considering the SIIG and CSI indices and examining the grain yield in two stress and non-stress environments, we can choose 427, 283, 296, 223, 340, 425, 39, 361, 389, 352, 361, 110 and 117 lines which not only have high yield, but also have optimal 1000-seed weight and suitable spike length for the development of salinity-tolerant cultivars in the continuation of the barley breeding projects using wild genome integration

محمد مهدي مجيدي

اقافخر ميرلوحي فلاورجاني , مهديه غلامي