Abstract Wild barley (Hordeum vulgare ssp. spontaneum), is a close relative and ancestor of cultivated barley, providing a rich and desirable source of genetic diversity for barley breeding. This species can easily be crossed with the cultivated barley and can be a suitable genetic source for improving tolerance to abiotic stress conditions such as drought and salinity. One of the challenges for breeders is the effective selection of genotypes resilient to these stresses, which can largely be achieved by using tolerance and sensitivity indices. This study aims to eva‎luate the genetic diversity in nested populations (NAM) resulting from interspecific hybridization and to identify recombinant inbred lines (RILs) with desirable agronomic characteristics and drought tolerance in barley. A population called IWB-21, , comprising 21 families derived from the hybridization between 21 populations of H. spontaneum and an Iranian cultivar (Reyhan 03), containing a total of 443RILs was used. In fact, when the wild genome (21 wild accessions) (Foreground) is intogressed as donor parent into the genetic background of Rehan 03 cultivar (Background) through backcrossing and selfing, each donor parent contributes portions of its chromosomal fragments to the recurrent parent. , As a result, valuable genetic diversity for the selection of important traits and for genetic studies becomes available. In this study, 443 RILs along with 4 control cultivars (Bahrokh, Yousuf, Nik and Mahtab) were eva‎luated under normal and salinity stress (irrigated with 20 dS m-2 saline water) using an augmented design. The experiment was conducted over two years (1401 and 1402) at the research farm of the College of Agriculture, Isfahan University of Technology.. The results showed high genetic diversity among the populations and RILs, indicating successful introgression of tolerance to salinity stress, as revealed by agronomic and phenological traits. The results of the mean comparisons among the populations showed that nesting and the use of multiple wild parents to introduce diversity into the genetic background of the cultivated variety have varying effect on the tolerance to salt stress. This variation indicates the transfer of different chromosomal parts from various wild accessions to the cultivated barley. Populations B1R67, B1R48, and B1R21 with wild donor parents originated from Iraq, Iran, and Turkmenistan, respectively, performed superior than other populations 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. To increase the selection efficiency in the stress environment, univariate and multivariate indices were used. SIIG (calculated using morphological and yield traits) and CSI (calculated based on a combination of other indices) indices were recognized as suitable criteria for selecting stable and high performance lines in both stress and normal environments. Considering the SIIG and Standardized average of Indeces and the yield in both normal and salt stress environments, the lines 204, 248, 283, 287, 316, 400, 217, 211, and 386 were identified as suitable for developing salinity-tolerant barley cultivars through wild genome integration. These lines not only exhibited high yield but also had optimal thousand seed weight, Number of stems and spike length.

محمد مهدي مجيدي , احمد ارزاني

قدرت اله سعيدي , سعيد انصاري مهياري