Genetic diversity analysis and population structure of selected Ethiopian durum wheat (T. turgidum subsp. durum) landraces using DArTSeq markers

Abstract

Genetic variability is crucial for developing high-yield varieties adaptable to diverse climatic conditions, Ethiopia, a center of diversity for durum wheat holds significant genetic resources in its germplasm. However, these landraces, have limited responses to current and future crop breeding challenges. This study investigates SNP-based genetic diversity, linkage disequilibrium, and population structure of durum wheat using 94 accessions categorized into Dega and W. dega populations based on altitude based agroecological patterns. The study identified 14,136 high-quality SNP markers with known physical positions, distributed across the A (6691) and B (7445) genomes. The 2B chromosome had the highest marker density, while the 4A had the lowest. Genome-wide mean values of Nei's gene diversity (0.199) and polymorphism information content (0.184) indicate significant genetic diversity within this collection. The minor allele frequency ranged from 0.005 to 0.5, with a mean of 0.184. Structure analysis classified the landraces into three distinct subpopulations (K = 3), though the grouping pattern did not correlate with agroecological patterns, suggesting high admixture likely due to historical seed exchanges among Ethiopian farming communities. This was further confirmed by the Analysis of Molecular Variance (AMOVA). The findings provide insights for wheat genetic improvement, supporting association mapping and genomic prediction. High genetic diversity in Ethiopian durum wheat landraces offers valuable traits for stress resilience, emphasizing the need for policies that conserve diverse landraces to enhance food quality and sustainable, climate-resilient production.

Keywords

• Ethiopian durum wheat
• Genetic diversity
• Landraces
• Linkage disequilibrium
• Population structure
• SNP markers