Improvement of Endosperm Hydration Counter the Negative Relationship Between Dormancy and Malt Quality in Barley (Hordeum vulgare)

Abstract

Dormancy in barley has been thoroughly studied and shown to negatively impact malt quality, resulting in selection against dormancy. However, reduced dormancy coincides with increased preharvest sprout (PHS) risk, thus sparking a new interest in integrating dormancy back into American barley lines if the negative effects of dormancy on malt quality can be overcome. We evaluated the dormancy and hydration index (HYI) in a biparental mapping population to determine the genotypes that would protect against PHS but have good malt quality. We found 4 HYI QTLs and 4 dormancy QTLs, one of which was near the well-described SD2 QTL. The HYI QTLs were pleiotropically related to seed size (1H), dormancy (5H) and malt quality (2H). Lines with dormancy (5H) and increased HYI (2H and 3H) had malt quality similar to nondormant lines while maintaining PHS resistance, suggesting improvements in HYI could be the key to overcoming the negative effects of dormancy in malting.