MARKER REGRESSION MAPPING OF QTL CONTROLLING FLOWERING TIME AND PLANTHEIGHT IN A SPRING BARLEY (HORDEUM-VULGARE L) CROSS

An RFLP map was constructed from 99 doubled haploid lines of a cross b etween two spring barley varieties (Blenheim x Kym) and used to map qu antative trait loci (QTL) controlling ear emergence time and plant hei ght using a marker-regression approach. Three QTL affecting plant heig ht were identified. The largest effect was from the dense dwarfing gen e, present in Blenheim, on chromosome 3(3H)L. Two other effects were f ound, one on 7(5H)L and one on 1(7H)L. The denso gene also had a major effect on ear emergence time. However, eight additional QTL for ear e mergence were also identified. Two of these were in regions previously identified as carrying the Sh and Sh2 vernalization response genes, s uggesting that allelic variation at these genes may affect ear emergen ce time in spring barley crosses. Comparisons with maps of related spe cies show conservation and collinearity of markers and genes.