Quantitative trait loci for heading date and straw characters in barley

Abstract

Quantitative trait loci (QTLs) for heading date and straw characters were examined in 79 chromosome-doubled haploid lines derived from the F1generation of a cross between a six-rowed winter barley and a two-rowed spring barley. A genetic map covering 1100 cM containing 85 markers, including isozyme, morphological, RFLP, and RAPD markers, was constructed. All traits examined had two QTLs with large effects on chromosome 2. In addition, a QTL for length of the top internode was found on 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 found in both 1989 and 1991. The results indicate that two QTLs on chromosome 2 affect a group of correlated traits.Key words: Hordeum vulgare, earliness, RFLP, two rowed, six rowed, linkage map.