Genetic Variability and Association of Morpho-Agronomic Traits Among Ethiopian Barley (Hordeum vulgare L) Accessions

Barley is considered to have Ethiopia as its center of diversity, and it is among the most prominent cereal crops cultivated across different agroecology in the country. However, the available germplasm in the country has not been studied much compared to the number of accessions under conservation and the expected diversity of crops in the country. This study was therefore conducted to estimate the phenotypic variability and association of morphoagronomic traits among 49 barley accessions. The experiment was conducted in 2021 using a 7 x 7 simple lattice design. The results of the analysis of variance indicated significant differences among the accessions for all traits. Moreover, with a mean of 4.02 t<middle dot>ha-1, the variation in accessions for grain yield ranged from 2.18 to 6.89 t<middle dot>ha-1. The phenotypic and genotypic coefficients of variation varied in the range between 7.25% (days to maturity) and 35.18% (weight of kernels per spike) and 6.61% (peduncle length) and 32.25% (weight of kernels per spike), respectively. Broad-sense heritability and genetic advance as a percentage of mean varied from 43.18 (number of fertile tillers) to 92.5% (days to heading) and 11.87% (peduncle length) to 60.99% (weight of kernel per spike), respectively. Grain yield had positive phenotypic and genotypic correlations with the majority of traits. Moreover, the number of spikelets per spike followed by the number of fertile tillers, thousand kernel weight, and number of kernels per spike had strong positive associations with grain yield and they had a direct, positive genotypic effect on grain yield. Consequently, while selecting accessions for high grain yields, these traits should be considered as well. The Euclidian distances of accessions estimated from quantitative traits ranged from 1.07 to 9.24, and the accessions were clustered into six distinct clusters. Clusters V (32.65%), II (26.5%), VI (24.49%), and IV (12.25%) consisted of the largest proportion of accessions, whereas Clusters I and III consisted of one accession each. From principal components' analysis, 79.65% of the variance was explained by three main components with eigenvalues greater than one. Thus, the current findings suggest that there is wide genetic variation among accessions which may be used for crop improvement and the information generated could also be utilized for genetic conservation.