The SD1 locus affects primary seed dormancy in winter malting barley.

Area of Science:

• Agricultural Science
• Plant Genetics
• Crop Breeding

Background:

• Preharvest sprouting (PHS) resistance and seed dormancy are critical for malting barley (Hordeum vulgare L.) quality, especially in rainy harvest conditions.
• Research on these traits in winter malting barley is less extensive than in spring varieties within the United States.

Purpose of the Study:

• To map PHS resistance and seed dormancy traits in a winter malting barley population.
• To identify genetic markers associated with seed dormancy and its rate of loss.
• To investigate the role of the Seed Dormancy locus 1 (SD1) in winter malting barley.

Main Methods:

• Utilized a modified half-sibling winter malting barley breeding population.
• Mapped PHS resistance and germination traits during after-ripening.
• Identified marker associations with dormancy and the rate of dormancy loss.
• Characterized the H. vulgare L. alanine aminotransferase (HvAlaAT) gene at the SD1 locus.

Main Results:

• The SD1 locus, identified as the HvAlaAT gene, was significantly associated with the rate of primary seed dormancy loss.
• Additional quantitative trait loci (QTLs) for PHS resistance and seed dormancy were identified.
• Specific markers for HvAlaAT alleles and other QTLs were pinpointed.

Conclusions:

• The identified markers for HvAlaAT alleles and other QTLs offer enhanced precision for breeding malting barley.
• Selection can be improved for lines exhibiting high PHS resistance and controlled dormancy periods.
• This facilitates the production of high-quality malt with reduced preharvest sprouting issues.