Multivariate analysis of agro-morphological traits to unlock the genetic divergence of Ethiopian cultivated barley (Hordeum vulgare L.) genotypes

Barley is a prominent cereal crop and a center of diversity in Ethiopia, with a huge collection in the genebank. However, its productivity in the country remains low due to the underutilization of the available genetic resources. Thus, the study aimed to explore the genetic divergence and association of agro-morphological traits and identify the highest-performing barley genotypes through multivariate analysis. The experiment was conducted using an alpha lattice design with 128 barley genotypes across three barley growing locations over two cropping seasons (2021 and 2022). A combined analysis of variance revealed highly significant ( p < 0.001) differences among genotypes, environments, and their interactions for all eleven agro-morphological traits. Correlation analysis revealed that grain yield was positively associated with days to heading, maturity, plant height, productive tillers, spikelets per spike, kernels per spike, and biomass yield. Principal component analysis identified four components explaining 82% of the total variation, with the first component (41%) heavily influenced by yield-related traits. Cluster analysis grouped the genotypes into six distinct clusters, with the greatest genetic distance observed between Clusters I and V, indicating high genetic divergence. The clustering pattern was not based on geographic origin, highlighting the presence of subtle genetic variation across regions. Genotypes in Cluster III were characterized by high yield and late maturity, while those in Cluster VI were early maturing. The substantial genetic diversity uncovered provides valuable resources for selecting superior parental lines to develop improved barley varieties with enhanced yield and adaptability.