Barley semidwarf allele sdw1.d improves malting quality indirectly in a near isogenic line

Background and Objectives Malt barley is a specialty crop in which quality characteristics are as important as grain yields. Short stature genes used to increase grain yields in barley have variable effects on malt quality. Effects of sdw1.d semidwarf gene on malting quality were examined using a near isogenic line (NIL) in six field trials. Findings sdw1.d increased malt extract percentage significantly in five trials by 1.7% and decreased test weight (2.0–3.5 kg) in three trials. Grain weight increased in three trials where lodging was common while decreasing in two where lodging was not severe and not changing in one. Diastatic power of sdw1.d NIL was significantly higher in four trials and similar in two trials compared to recurrent parent Tokak. No change was observed for α‐amylase activity. Conclusions The lack of reports indicating a direct association of Sdw1 mutants with diastatic power and the presence of quantitative trait locus (QTL) around the Sdw1 gene in numerous studies implied that higher diastatic power of the NIL could be due to linkage rather than the pleiotropic effect of sdw1.d . Significance and Novelty Improved malting quality of the NIL appeared to be the result of indirect effects of sdw1.d due to reduced lodging and linkage with diastatic power QTL.