VERIFICATION OF BARLEY SEED DORMANCY LOCI VIA LINKED MOLECULAR MARKERS

Seed dormancy is a relatively complex trait in barley (Hordeum vulgare L.). Several dormancy loci were identified previously by quantitative trait locus analysis. Three reciprocal crosses were made in the prese nt study between parents carrying specific dormancy alleles via linked molecular markers to verify individual dormancy locus effects and pot ential expression. Analyses of F-2 progenies revealed that the dormanc y allele at the locus flanked by the markers Ale and ABC302 on the lon g arm of chromosome 7 had a major effect on dormancy, and was at least partly epistatic to the dormancy locus in the ABC309-MWG851 interval near the telomere of the long arm of chromosome 7. In the absence of t he dormancy allele in the Ale-ABC302 interval, the allele in the ABC30 9-MWG851 interval exerted moderate to large effects on dormancy. Cytop lasmic effects on dormancy were also observed. The germination percent ages of progeny with relatively high levels of dormancy were more vari able than those of non-dormant or less-dormant progeny, apparently due to environmental effects. Removal of the dormancy allele in the Ale-A BC302 interval, or introducing the dormancy allele in the ABC309-MWG85 1 interval, should suffice for adjusting dormancy levels in breeding p rograms to suit various production situations and end uses. The verifi cation of dormancy loci via linked molecular markers allows manipulati on of these loci in applied breeding programs.