Mapping QTLs associated with salt tolerance related traits in wheat (Triticum aestivum L.)

Salinity stress is a major limitation in wheat production. The lack of economically viable methods for screening salinity tolerance in field is an obstacle to breeders. In this study a population of ۲۵۴ recombinant inbred lines (RILs), derived from a cross between Roshan × Sabalan was assessed in glasshouse during the seedling phase in order to identify quantitative trait loci (QTLs) for salinity related traits. A genetic linkage map was constructed from ۲۳۹ markers, namely, ۲۲۵ Diversity Arrays Technology markers (DArTs) and ۱۴ simple sequence repeats (SSRs) which spanned a total of ۱,۰۹۹.۷cM. A total of ۳۱ QTLs for salinity tolerance were identified on ۱۳ chromosomes, contributing more than ۵۰% of the total phenotypic variation. The frequency of Roshan and Sabalan alleles were high at loci on different homeologous groups. Most of the detected QTLs were located on chromosomes ۳B, ۵B among the ۱۳ chromosomes. Two QTL related fresh weight and height of shoot were detected on ۱A and ۳A which explained ۱۸% and ۱۲.۹% of the total phenotypic variation respectively. Roshan (salt tolerance) alleles were associated with an increase in all traits under both control and stress conditions. SSR markers gwm۶۲۶ and gwm۵۴۰ (on chromosomes ۶B and ۵B, respectively) were tightly linked with different QTLs under control and stress conditions, and explained ۲۱.۱% and ۸.۱% of the total phenotypic variance, respectively. Some of these QTL mapped to genomic regions previously associated with salt tolerance in wheat.