Backcross Gains for Six-Rowed Grain and Malt Qualities with Introgression of a Feed Barley Yield QTL

Abstract

Fifty experimental barley lines were derived from a backcross of Morex and DH72, using the latter as donor parent of the Steptoe chromosome 3. These BC1 derived lines, plus the parental checks, were grown by the Montana Agriculture Experiment Station in irrigated and dryland experiments at Bozeman in 1994 and 1995 and in a dryland trial at the Havre station in 1995. The Steptoe chromosome 3 carries positive-value alleles for head-shattering and lodging resistance quantitative trait loci (QTL) that effectively increased relative yield and adaptation characteristics in the environments tested. These parents and lines were used to test the hypothesis that Morex-level malt quality characteristics can be recovered by backcrossing, with the addition of the yield-enhancing genes from the Steptoe chromosome 3. Four grain quality traits were analyzed in all five experiments, and nine malting traits were analyzed from micromalted samples from the 1995 Bozeman irrigated experiment. The results support the contention that the Steptoe chromosome 3 yield QTL has no adverse pleiotropic effects on malt quality, relative to Morex, although a slight decline in test weights may occur (~1–2% of the average observed over all experiments).