Mapping of QTLs controlling barley agronomic traits (Hordeum vulgare L.) under normal conditions and drought and salinity stress at reproductive stage

The present study is focused on mapping the genomic regions for controlling some agronomic traits in the reproductive stage of barley under normal, drought and saline conditions. In this regard, a total of 103 samples of F8 families derived from the cross of two cultivars of BadiaxKavir were planted in a completely randomized design in the crop year 2018-2019. The research procedure has been accomplished in the greenhouse of Gonbad Kavous University in three replications. In this case, transgressive segregation was observed for the evaluated traits. This situation indicated the difference between allelic interactions in the parents. Also, linkage maps were prepared using 152 SSR polymorphic markers, 72 ISSR alleles, 7 IRAP alleles, 29 CAAT alleles, 27 SCoT alleles, and 15 iPBS alleles. These markers were assigned to the seven barley chromosomes. Thus, the obtained map covered 999.29 centiMorgans (cM) of the barley genome length, and the average distance between two flanking markers was 3.387 cM. In this study, the most significant QTL under normal conditions have been identified on chromosomes 1, 5, and 6. In the drought conditions, four major QTLs were detected for spike diameter, awn weight, flag leaf weight (qPPT-7, qAWW-7, qFLW-4a and qFLW-5). Under salinity stress conditions, two major QTLs were identified for the number of leaves qLEN-6a and shoot diameter qSHT-6b. In this case, the values of R2 were 18.3 and 17.6, respectively. The major QTLs that control the effect of the desired traits and the markers associated with them can be used in marker-assisted selection programs.