Barley (Hordeum vulgare L.) is widely cultivated for animal feed, human consumption, and most notably, for malting. Malt quality is determined by both genetic and environmental factors, and its improvement requires a clear understanding of the genomic regions controlling related traits. This study aimed to investigate the genetic basis of malt quality traits in Ethiopian barley genotypes using multi-locus genome-wide association studies (ML-GWAS). A barley panel of 260 were evaluated for malt quality traits across four sites in Ethiopia. ML- GWAS were performed on five traits related to malt quality using the information on Illumina 50 K iSelect single nucleotide polymorphisms (SNPs). Six different models were used for the ML-GWAS analysis. Significant variation in malt quality traits was observed across the studied genotypes. Extract Content (EC) ranged from 81.66% to 60.00%, while Protein Content (PC) varied between 17.63% and 9.03%. These traits exhibited moderate to high narrow-sense heritability, ranging from 72% for EC to 69% for GS, indicating strong genetic control and promising potential for selection in breeding programs. The coefficient of variation (CV) for all traits ranged from 5.37% to 32.63%. K-means clustering grouped the association panel into 5 distinct clusters. The principal component analysis (PCA) covers 76.1% variation. The genotypes B115.1, B248, B248 and B31.2 are the best overall performance across malt quality traits. The relative importance of the trait is BGC > EC > PC > GS. ML-GWAS identified 19 significant QTNs associated with malt quality traits. The Significant QTNs exhibited LOD scores ranging from 3.06 to 5.36 and r² values between 6.98% and 25.35%, and minor allele frequencies (MAF) from 0.054 to 0.465. The highest number of significant associations was detected on chromosomes 4 H, 6 H, and 7 H. The identified QTNs represent promising molecular markers for improving malt quality through marker-assisted selection, providing valuable tools for developing superior malting barley cultivars in Ethiopia. Further functional validation of these loci will contribute to a deeper understanding of the genetic architecture underlying malt quality traits in Ethiopian barley.
Babiye et al. (Sun,) studied this question.