A field experiment was conducted using 36 rice genotypes in 2017 at two locations of Southwestern Ethiopia to estimate the extent and pattern of genetic variation and association among yield and yield related traits. The experiment was laid down in 6 × 6 simple lattice design. The combined analysis of variance over the two locations revealed that the genotypes showed significant differences for all the traits studied, except for days to heading, panicle weight, thousand seed weight, lodging incidences, leaf blast and brown spot. Although, genotype × location interactions was significant for days to maturity, plant height, fertile tillers per plant, unfilled spikelets per panicle, panicle shattering, biomass and grain yield. Moderate to high broad sense heritability was observed for days to maturity, panicle length, total tillers per plant, fertile tillers per plant, filled spikelets per panicle, unfilled spikelets per panicle, biomass yield, harvest index, panicles per square meter and plant height. Among the studied traits total tillers per plant, fertile tillers per plant, panicles per square meter, biomass yield and harvest index had moderate values of genetic advances as percent of mean. Grain yield showed positive and significant correlations with days to maturity, panicle length, fertile tillers per plant, panicles per square meter, biomass yield and harvest index at both genotypic and phenotypic levels. Phenotypically, panicles per square meter and genotypically, harvest index exerted the maximum positive direct effect on grain yield. The study revealed that panicles per square meter and harvest index can be considered for selection in future rice breeding program and in order to give confirmative results, further studies in more locations and years, supported with molecular breeding approach should be conducted.
Keywords: Upland rice, Variability, Heritability, Genetic advance, Trait association.