Abstract

A field experiment was conducted with the objective of determining the magnitude of genetic diversity among rainfed lowland rice genotypes. Twenty-five rainfed lowland rice genotypes were evaluated during the 2016 main cropping season at two rainfed lowland agro-ecologies of Southwestern Ethiopia. The experiment was laid out in a simple lattice design and data on 14 yield and yield component traits were collected and subjected to various statistical analyses. Cluster and distance analysis of quantitative characters based on multivariate analysis pointed out the existence of four divergent groups. The maximum inter cluster distance was observed between cluster one and four (D2=258.7) followed by cluster one and three (D2=191.5), while the minimum was obtained between cluster one and two (D2=45.06). Maximum recombination and segregation of progenies were expected from crosses involving parents selected from these divergent groups. Principal component analysis retained the first five principal components that accounted for 76.5% of the total variation in lowland rice genotypes and the first two principal axis contributed 43.7% for the total variation in lowland rice genotypes. Number of fertile tillers plant, thousand seed weight, grain yield per plant and harvest index in different principal components as the most prominent traits for differentiation of the total variation in lowland rice genotypes. The present study indicated sufficient amount of genetic diversity for the majority of the characters studied in rain-fed lowland rice genotype for future exploitation and, could be kept into consideration during hybridization and conservation programs.