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.
