Phenotypic Variability, Heritability, and Performance Evaluation of Bread Wheat ( <i>Triticum aestivum</i> L.) Genotypes for Grain Yield and Yield‐Related Characters in North West Ethiopia

Abstract

Bread wheat serves as a crucial staple crop globally, including in Ethiopia, but faces challenges related to yield reduction due to environmental constraints. Consequently, this research aimed to assess the phenotypic variability and performance of 12 bread wheat genotypes for grain yield (GY) and yield‐related traits in northwest Ethiopia. The field experiment was conducted over 2 years in two environments (Ayehu Guagusa and Dangila). A third environment (Guagusa Shekudad) was added during the second cropping season, making the total number of environments three. These experiments were conducted using a randomized complete block design (RCBD) with three replications during the main cropping seasons of 2021/2022 and 2022/2023. The combined analysis of variance (ANOVA) showed a highly significant ( p &lt; 0.001) interaction between environments and genotypes for all traits, except plant height (PH). These results suggest that the genotype effect had a stronger influence than the environment, implying high heritability values and potential for successful genotype selection in broader adaptation areas. The combined analysis across two environments over 2 years showed that the broad‐sense heritability values ranged from 58.82% for aboveground biomass (AGB) to 100% for GY. Notably, the ANOVA revealed high heritability associated with significant genetic advance (GA) as a percent of mean for traits such as the number of tillers per plant (TPP) (78.57%, 34.4%), PH (93.11%, 25.38%), spike length (SL) (71.08%, 20.25%), 1000‐kernel weight (TKW) (71.04%, 24.38%), harvest index (HI) (71.11%, 22%), and GY (100% and 30.4%), respectively. Therefore, these traits should be a focus in the bread wheat breeding program, as their phenotypic expression is influenced by additive gene action. Consequently, direct selection for these traits will enhance GY. From the combined analysis of 2 years over two locations, and for the second cropping season at three locations for 1 year, the genotypes G6 (2.78 t/ha, 3.57 t/ha), G7 (2.84 t/ha, 3.58 t/ha), G8 (2.87 t/ha, 3.48 t/ha), and G12 (2.83 t/ha, 3.26 t/ha), respectively, demonstrated the highest GY performance across the environments and are recommended for local farmers. These findings provide valuable insights into the genetic potential of the tested bread wheat genotypes, which can be utilized in breeding programs to develop high‐yielding and well‐adapted cultivars for the study area.