Marker regression mapping of QTL controlling flowering time and plant height in a spring barley (Hordeum vulgare L) cross

An RFLP map was constructed from 99 doubled haploid lines of a cross between two spring barley varieties (Blenheim x Kym) and used to map quantative trait loci (QTL) controlling ear emergence time and plant height using a marker-regression approach. Three QTL affecting plant height were identified. The largest effect was from the dense dwarfing gene, present in Blenheim, on chromosome 3(3H)L. Two other effects were found, 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 emergence were also identified. Two of these were in regions previously identified as carrying the Sh and Sh2 vernalization response genes, suggesting that allelic variation at these genes may affect ear emergence time in spring barley crosses. Comparisons with maps of related species show conservation and collinearity of markers and genes.