Assessment of Genetic Variability in Upland Rice (Oryza sativa L.) Genotypes at Metema, Northwestern Ethiopia

Abstract

Rice holds promise to meeting food demand and ensuring social stability in Ethiopia. However, the country demand for rice far exceeds its production, with 80% of the deficit being met through imports. Hence, identification and utilization of genetically diverse genotypes is essential for crop improvement programs to develop and deploy high yielding rice varieties. This study was conducted with the objective to assess genetic parameters and determine the extent of genetic diversity among 81 upland rice genotypes. Field study was carried out in Metema during the 2021 main cropping season, using a 9x9 simple lattice design with two replications. Eighteen agro-morphological traits were analyzed using various multivariate techniques and genetic parameter estimation methods. Analysis of variance revealed highly significant differences among genotypes for all the traits studied. Moderate to high genotypic and phenotypic coefficients of variations were found for days to heading, days to maturity, filled grains per panicle, and grain yield. Moderate to high heritability, coupled with genetic advance as a percentage of the mean, were observed for thousand grain weight, grain yield, and filled grains per panicle, suggesting that these traits could be improved through direct selection. Cluster analysis grouped the 81 genotypes into six clusters. The inter-cluster distance was greatest between Cluster IV and Cluster V (D² = 261.62), indicating that these clusters could be valuable for hybridization programs. The first five principal components accounted for 75.56% of the total variability in the 18 traits, providing insight into the traits that differentiate the genotypes. The result of this study suggests existences of adequate genetic variability among the genotypes, which could be recommended for future rice improvement programs.