Verification of a quantitative trait locus affecting agronomic traits in two-row barley

Quantitative trait loci (QTL) affecting agronomic traits have been mapped in barley (Hordeum vulgare L.), but there have been few experimental verifications of the presence and effect of individual QTL. Here, we report on verification of a QTL on the "plus" arm of chromosome 7(5H) of barley. This QTL, affecting grain yield, plant height, maturity, and lodging severity, had been mapped in the two-row barley cross 'Harrington'/'TR306', on the basis of evaluation of 145 doubled haploid lines in 30 field experiments. We used molecular marker genotypes to select 47 lines from among 410 Harrington/TR306 lines that had not been used in the original mapping experiment. Comparisons among groups of lines with contrasting marker genotypes on chromosome 7(5H) confirmed that a QTL on the "plus" arm of that chromosome affects grain yield, plant height, and lodging severity. The presence of TR306 alleles at this QTL contributed to small increases in grain yield and plant height, and reduced lodging severity. The results of this study confirmed the presence of a QTL affecting several agronomic traits, but also demonstrated that the effect of individual QTL may be small and may vary among environments.