Mapping QTLs Associated with Salt Tolerance Related Traits in Seedling Stage of Wheat (Triticum aestivum L.)

Abstract

Salinity stress is a major limitation in wheat production. The lack of economically viable methods for screening salinity tolerance in the field is an obstacle to breeders. In this study, a population of 254 recombinant inbred lines (RILs), derived from a cross between two bread wheat cultivars, namely, Roshan × Sabalan, was assessed in glasshouse during the seedling phase in order to identify quantitative trait loci (QTLs) for salinity-tolerance related traits. A genetic linkage map was constructed from 239 markers, namely, 225 Diversity Arrays Technology markers (DArTs) and 14 simple sequence repeats (SSRs) which spanned a total of 1,099.7 cM. A total of 31 QTLs for salinity tolerance were identified on 13 chromosomes, contributing more than 50% of the total phenotypic variation. The frequency of Roshan and Sabalan alleles were high at loci in different homeologous groups. Most of the detected QTLs were located on chromosomes 3B and 5B, among the 13 chromosomes. Two QTLs related to fresh weight and height of shoot were detected on 1A and 3A, which explained 18% and 12.9% 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 gwm626 and gwm540 (on chromosomes 6B and 5B, respectively) were tightly linked with different QTLs under control and stress conditions, and explained 21.1% and 8.1% of the total phenotypic variance, respectively. Some of these QTLs mapped to genomic regions previously associated with salt tolerance in wheat. Keywords: QTL, RILs, Salinity, Seedling.