Phenotypic variability of sorghum (Sorghum bicolor L. Moench) for quantitative traits in Northeast Ethiopia

Enhancement of sorghum genotypes depends on the magnitude of genetic variability within the base population. The objective of this study was to assess the magnitude of genetic variation, heritability and expected genetic advance in sorghum genotypes. Forty-nine genotypes were evaluated on a 7*7 simple lattice design at Sirinka Agricultural Research Center, Northeastern part of Ethiopia. The result of analysis of variance showed significant (P < 0.001) variation for all of the investigated traits except stalk diameter and panicle width, indicating the existence of higher degree of genetic variability in the sorghum genotypes. The genotypes showed wider variability in grain yield which ranged from 0.40 to 3.1 t ha -1 with a mean value of 1.71 t ha -1 . The higher values of genotypic and phenotypic coefficients of variation were obtained for grain yield (32.56%; 37.45%), harvest index (43.09%; 48.76%) and grain weight per panicle (23.60; 32.8123.60%). Grain yield, harvest index, Plant height and panicle weight had high heritability along with high genetic advance as percent of means. These traits could be improved through direct selection. The first three principal components (PCs) explained 73.9% of the total variability in the genotypes. Traits with higher loadings in PC1 and PC2 are most important in explaining the variability and discriminating the sorghum genotypes.