Evaluation and application of molecular marker sets for developing PHS-resistant wheat in Korea

Pre-harvest sprouting (PHS) is a major constraint on wheat production in Korea, reducing grain quality and end-use value. To accelerate the development of PHS-resistant cultivars with improved agronomic performance, we employed a marker-assisted backcrossing (MABC) approach using molecular markers previously reported in the literature. For foreground selection, 81 molecular markers (74 KASP and 7 gel-based) targeting key genes related to PHS resistance, grain quality, and disease resistance were applied. Genome-wide background selection was conducted with 547 KASP markers to monitor recovery of the recurrent parent genome. Genotyping of 94 wheat accessions revealed distinct genetic clustering among domestic cultivars, introduced germplasm, and 1BL.1RS rye translocation lines, demonstrating the effectiveness of the marker set in capturing genome-wide diversity. Using MABC combined with speed breeding, three elite lines were developed by pyramiding favorable alleles from ‘Joongmo2008’ and ‘Tapdong’. Among them, ‘Milyang55’ exhibited strong PHS resistance (germination rate: 21.1%), desirable agronomic traits, and flour quality comparable to ‘Joongmo2008’. Donor genome proportions ranged from 25.5 to 43.0%, confirming efficient recovery of the recurrent parent genome. These results highlight the utility of integrating pre-selected molecular markers with MABC and speed breeding for the rapid development of elite wheat cultivars with improved PHS resistance and end-use quality.