Analysis of Genetic Variability Among Bread Wheat (<i>Triticum aestivum</i> L.) Genotypes for Growth, Yield and Yield Components in Bore District, Oromia Regional State

In Ethiopia, a number of improved bread wheat ( Triticum aestivum L.) varieties have been released by different research centres. All of these varieties were, however, not evaluated in Bore District for growth, yield and yield components which are necessary for identification of adaptable varieties for this major wheat growing District. Field experiments was conducted in 2013/14 cropping season by utilizing 21 released varieties and 4 promising lines using Randomized Complete Block Design where genotypes were replicated three times and 14 characters were recorded. Results of the analysis of variance revealed that genotypes were differed significantly for all characters studied. Genotypic coefficient of variation (GCV) ranged from 4.59 (days to maturity) to 13.76% (grain yield per hectare), while phenotypic coefficient of variation (PCV) ranged between 5.03 (days to maturity) to 20.85% (grain yield per hectare). Heritability in broad sense and genetic advance as percent of mean (GAM) ranged from 33.33% (Tillers per plant) to 84.67% (Peduncle length) and 8.66% (Days to maturity) to 18.74% (grain yield per hectare), respectively. Grain yield per hectare was positively correlated with biological yield per plot and harvest index, but was negatively correlated with peduncle length both at genotypic and phenotypic level. The computed path coefficient for yield showed that days to maturity, number of productive tillers, and biological yield per plot, harvest index, and spike length had positive direct effect, while days to heading and grain filling period, had high negative direct effect at both genotypic and phenotypic levels. Generally, it has been observed the presence of variability among the genotypes studied and 18.74% grain yield gain is possible by exerting 5% selection intensity which can be exploited to improve yield in the District.