Mapping QTLs for salt tolerance with additive, epistatic and QTLxtreatment interaction effects at seedling stage in wheat

Quantitative trait loci (QTLs) for salt tolerance with additive, epistatic and QTLxtreatment interaction effects at seedling stage in wheat were identified. A set of 131 recombinant inbred lines derived from cross Chuan 35050 x Shannong 483 were evaluated under salt stress and normal conditions. Wide variation was found for all studied traits. A total of 18 additive and 16 epistatic QTLs were detected, among which five and 11 were with significant QTLxtreatment effects. Ten QTL clusters were identified, and each may represent a single gene or closely linked genes. The locus controlling shoot K+/Na+ concentration ratio and shoot Na+ concentration on chromosome 5A may be identical to Nax2. The interval Xgwm6-Xgwm538 on chromosome 4B for total dry weight was also identified in a previous study, both near the marker Xgwm6. The marker Xgwm6 may be useful for marker-assisted selection. Six pairs of homoeologous QTLs were detected, showing synteny among the A, B and D genomes. These results facilitate understanding the mechanisms and the genetic basis of salt tolerance in wheat.