Genetic Diversity and Genome‐Wide Association Study of Grain Quality in Sorghum ( <scp> <i>Sorghum bicolor</i> </scp> ) Landrace Collections

ABSTRACT Sorghum ( Sorghum bicolor ), a staple crop in Ethiopia, demonstrates remarkable genetic diversity, making it invaluable for global breeding initiatives to enhance crop resilience and yield. However, limited genetic understanding hinders the development of high‐quality sorghum varieties, delaying breeding efforts to tackle nutritional deficiencies. This study investigated the associated genetic loci in 358 Ethiopian sorghum landraces to assess grain quality traits across two seasons (2020–2021) at three locations (Melkassa, Jimma and Miesso). Using genome‐wide association study (GWAS) techniques with 209,572 SNPs, we identified loci associated with grain quality traits, leveraging FarmCPU and BLINK models for accurate marker detection. Environmental conditions at Jimma and Melkassa enhanced gene expression for starch and amylose, whereas under Miesso conditions showed higher expression of protein‐related genes. Five loci S01_31764844, S01_73075918, S04_53545349, S06_48180471 and S06_59687350 are associated with starch biosynthesis and connected to genes involved in sugar transport, stress response and cell wall stability. Three loci (S01_67415726, S07_62671638 and S10_21605004) were associated with amylose content, linked to genes influencing starch synthesis and regulatory functions. For protein composition, loci on chromosomes 1, 2 and 9 (S01_1332500, S02_3743197 and S09_3030812) encode proteins involved in cellular structure, nucleic acid metabolism and oxidative stress response. Notable candidate genes and proteins associated with these traits included stress response proteins (LEA and CCCH‐type zinc finger), transport proteins (ABC transporter and sugar carrier) and transcription factors (ARF12 for starch synthesis and WOX6 for stem cell regulation). This study highlights the associated molecular and candidate genes essential for developing resilient, high‐quality sorghum varieties adapted to diverse environmental conditions.