ASSOCIATIONS BETWEEN 23 QUANTITATIVE TRAITS AND 10 GENETIC-MARKERS IN A BARLEY CROSS

Associations of 23 quantitative traits and 10 genetic marker characters were examined in 63 chromosome-doubled lines (DH-lines) derived from the F1-generation of a cross between an old and a modern spring barley variety. One fourth of the marker x trait combinations showed significant associations. More than two thirds of these associations were to earliness (heading date). Earliness was found to be controlled by two loci: the previously known eak locus and a new locus designated Ea,,. It is concluded that the associations of quantitative traits with the earliness loci were caused by pleiotropy. Associations were found between two absolutely linked C-bands on chromosome 3 and QTLs (quantitative trait loci) for lodging, straw diameter, and length of top internode of the straw. The three loci on chromosome 5, eak and the two linked powdery mildew loci, Mla9 and Mlk, were associated with a possible QTL for magnesium concentration in grain. Association to the C-band on chromosome 6 suggests QTLs for TGW (thousand grain weight), straw diameter and magnesium concentration in grain. Locus Est1 on chromosome 3 was not associated with any of the quantitative traits.