Genetic Variability of Yield and Yield Related Traits in Bread Wheat (Triticum aestivum L.) Genotypes under Irrigation Condition in South Omo, Southern Ethiopia

Bread wheat (Triticum aestivum L), is a self-pollinating annual plant in the true grass family Gramineae (Poaceae), and is the largest cereal crop extensively grown as staple food source in the world. The objective of this study was to assess the genetic variability and genetic diversity among genotypes using a triple lattice design in Bena-Tsemay district in 2020 under irrigation conditions. The analysis of variance revealed highly significant variation (P≤0.01) among the genotypes for yield and yield components. Wide ranges of the mean values were observed for most of the traits like grain yield, plant height, days to maturity, and grain filling period, indicating the existence of variations among the tested genotypes. Moderate Phenotypic coefficient of variability and genotypic coefficient of variability was recorded for days to maturity, grain yield, and harvest index; while high heritability values were observed for plant height and days to heading. Among the studied characters grain yield showed high genetic advance. The D2 analysis grouped the 36 genotypes into six clusters. The maximum inter-cluster distance was observed between clusters V and VI (D2=777.99), followed by that between clusters III and V (D2=525.49) and I and III (D2=310.81), which showed that the genotypes included in these clusters are genetically more divergent from each other than those in any other clusters. Principal components (PC1 to PC6) having Eigen value greater than one, accounted for 75.6% of the total variation. The first three principal components, i.e., PC1, PC2, and PC3, with values of 22.0, 35.7, and 47.9, respectively, contributed more to the total variation. Generally, the results of this study showed the presence of variations among the studied genotypes for agro-morphology traits that could allow selection and/or hybridization of genotypes.