Phenotypic variability and traits associations in Ethiopian mustard ( <i>Brassica carinata</i> A. Braun) accessions: Implications for crop improvement

Abstract Brassica carinata A. Braun (Ethiopian mustard) is a dual-purpose crop cultivated for both leafy greens and oil-rich seeds; however, its genetic potential remains underexploited. This study evaluated 121 genotypes across two locations (Asela and Holeta) using a simple lattice design to assess phenotypic variability, heritability, yield, and related trait associations. Single-location ANOVAs revealed highly significant genotypic differences for most traits, indicating substantial within-location variability. Combined ANOVA further confirmed the influence of both genotype and environment, with significant genotype-by-environment interactions observed, particularly for flowering date, maturity date, main raceme length, seeds per silique, and seed yield per plant. High heritability (H 2 &gt; 0.7) and genetic advance as a percentage of the mean observed in silique per main raceme, leaf petiole length, seed yield per plant, and seed yield per hectare suggest that these traits are strong candidates for selection. Genotypic correlation analysis showed strong positive associations between seed yield and traits such as plant height, thousand-seed weight, and primary branches per plant, although correlations varied across locations. Path coefficient analysis revealed that traits such as seed yield per plant, flowering date, and main raceme length exerted strong positive direct effects on seed yield at both sites. Overall, the results demonstrated considerable genetic variability and trait interdependence among Ethiopian mustard accessions. This study provides key insights into the selection of stable, high-yielding genotypes and highlights the need for environment-specific breeding strategies to enhance the productivity and adaptability of B. carinata .