A model of the genetic differences in malting quality between European and North American barley cultivars based on a QTL study of the cross Triumph × Morex

11 Pags., 2 Tabls., 2 Figs.To study the genetic control of malting quality, in North American and European barley varieties, over five contrasting environments, 106 doubled haploid (DH) lines, from the cross ‘Triumph’ × ‘Morex’, were grown at Pullman (Washington State, USA) in 2002, Dundee (Scotland) in 2003 and 2005 and Lleida and Valladolid (Northern Spain) in 2006. The vrs locus, associated with two-row vs. six-row ear type, had a significant effect, as two-row lines had higher grain protein content at all sites. This had variable effects on other malting parameters, but hot water extract (EXT) was not significantly affected at the two Spanish sites. Quantitative trait loci associated with malting characters were distributed across all seven chromosomes, but the most influential, with effects on EXT and alcohol yield, at more than one site, were on 1H, with ‘Morex’ providing the increasing allele and 5H, with the increasing allele from ‘Triumph’. Transgressive segregation, in both directions, occurred at all sites. It was concluded that crosses between European and North American germplasm could enhance quality attributes in barley cultivated across diverse environments.The Centre UdL-IRTA forms part of the Centre CONSOLIDER INGENIO 2010 on Agrigenomics funded by the Spanish Ministry of Education and Science and acknowledges partial funding from DGCYT and INIA. The Scottish group is funded by the Scottish Government Rural and Environment Research and Analysis Directorate (RERAD). From the USA component of the study, technical field contributions by Vadim Jitkov are gratefully acknowledged, as well as financial support from the Washington State Univ., Col. of Agric., Human, and Nat. Res. Sci., Agric. Res. Cen. Proj. 1006 and the U.S. Barley Genome Project through the USDA-CSREES Special Grant 2006-34213-17026.Peer reviewe