QUANTITATIVE TRAIT LOCI FOR HEADING DATE AND STRAW CHARACTERS IN BARLEY

Quantitative trait loci (QTLs) for heading date and straw characters w ere examined in 79 chromosome-doubled haploid lines derived from the F -1 generation of a cross between a six-rowed winter barley and a two-r owed spring barley. A genetic map covering 1100 cM containing 85 marke rs, including isozyme, morphological, RFLP, and RAPD markers, was cons tructed. All traits examined had two QTLs with large effects on chromo some 2. In addition, a QTL for length of the top internode was found o n chromosome 6. The QTL in the chromosome segment around locus v (two row / six row) on chromosome 2 may be caused by pleiotropic effects of this locus. The same QTLs for heading date and straw length were foun d in both 1989 and 1991. The results indicate that two QTLs on chromos ome 2 affect a group of correlated traits.