MAPPING QUANTITATIVE TRAIT LOCI FOR SALT TOLERANCE AT GERMINATION ANDTHE SEEDLING STAGE IN BARLEY (HORDEUM-VULGARE L)

Quantitative trait loci (QTLs) controlling salt tolerance at germinati on and the seedling stage in barley (Hordeum vulgare L.) were identifi ed by interval mapping analysis using marker information from two doub led haploid (DH) populations derived from the crosses, Steptoe/Morex a nd Harrington/TR306. Interval mapping analysis revealed that the QTLs for salt tolerance at germination in the DH lines of Steptoe/Morex wer e located on chromosomes 4(4H), 6(6H), and 7(5H), and in the DH lines of Harrington/TR306 on chromosomes 5(1H) and 7(5H). In both DH populat ions, the most effective QTLs were found at different loci on chromoso me 7(5H). Genetic linkage between salt tolerance at germination and ab scisic acid (ABA) response was found from QTL mapping. The QTLs for th e most effective ABA response at germination were located very close t o those for salt tolerance on chromosome 7(5H) in both crosses. The QT Ls for salt tolerance at the seedling stage were located on chromosome s 2(2H), 5(1H), 6(6H), and 7(5H) in the DH lines of Steptoe/Morex, and on chromosome 7(5H) in the DH lines of Harrington/TR306. Their positi ons were different from those of QTLs controlling salt tolerance at ge rmination, indicating that salt tolerance at germination and at the se edling stage were controlled by different loci.