Quantitative trait loci diversity for salt tolerance at the early growth stage of barley (Hordeum vulgare L.)


bAgricultural and Natural Resources Research Center of Zanjan Province, Zanjan, Iran.


Salt tolerance in crops is multigenic in nature and quantitatively inherited, and therefore controlled by minor
genes. To study the diversity of QTLs conferring salt tolerance in barley, four barley mapping populations including L94 × Vada (L × V, 103 RILs), Oregon Wolf Barley (OWB) (Dom × Rec, 94 DHs), SusPtrit × Vada (Su × V, 152 lines), and SusPtrit × Cebada Capa (Su × CC, 113 lines) were tested; L × V and OWB showed unexpected segregation for salt tolerance at an early growth stage and were selected for this study. Two morphological traits (shoot length and total root length) were quantified under different salinity levels (0, 200 and 300 mM of NaCl) at an early growth stage. In total, eight QTLs were mapped in OWB and eight QTLs were mapped in L × V under 200 and 300 mM NaCl; of these, only two QTLs were common to the two populations. In the OWB and L × V populations, two and one QTLs were shared between two traits, respectively. Comparing QTL positions on a consensus map of barley showed that the number and location of the identified salt tolerance QTLs varied depending on the different NaCl concentrations and barley genotypes. Hence, there is a high diversity of QTLs conferring salt tolerance at the early growth stage of barley. In each barley genotype, a set of specific QTLs was responsible for salt tolerance and very few QTLs were common to them.