Evaluating the genetic effects of seed dormancy regulatory genes Qsd1 and Qsd2 in a global collection of cultivated barley (Hordeum vulgare ssp. vulgare) with functional kompetitive allele-specific PCR markers

Seed dormancy is agronomically important trait that associates with plant survival and seed production. Wild species present long dormancy to protect their seeds from unfavourable climate conditions until the next growing season. In contrast, shortened dormancy extends crop adaptability and promotes crop rotation in agriculture. However, the shortened dormancy brought about the risk of preharvest sprouting (PHS) on cereal crops in temperate and subtropical regions. Recently, two major quantitative genetic loci Qsd1 and Qsd2 that control the seed dormancy in barley have been cloned. In this study, two kompetitive allele-specific PCR (KASP) markers were developed and applied in a genotypic survey among 859 accessions of cultivated barley. Long-dormancy-associated alleles at both loci were over-represented within East Asian accessions. Both Qsd1 and Qsd2 had significant genetic effects on seed dormancy variations in cultivated barley. Thus, the two KASP markers could be applied in selecting favourable alleles in breeding practice to optimize the seed dormancy duration.