Avanços na ciência e tecnologia agrícola

Abstrato

Genetic variability and Associations among Yield and Yield Related Traits in Upland Rice (Oryza Sativa L.) Genotypes Evaluated at Southwestern Ethiopia

Awel Beshir , Sentayehu Alamerew, Wosene Gebreselassie

A field experiment was conducted using thirty six upland rice genotypes during the 2017 main rainy season 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 laid down in 6 × 6 simple lattice design. The combined analysis of variance over the two locations revealed that the genotypes showed highly significant (P≤0.01) differences for all the traits studied, except for days to 50% heading, panicle weight, thousand seed weight, lodging incidences, leaf blast and brown spot. Similarly genotype × location interactions revealed highly significant (P≤0.01) differences for panicle shattering and grain yield and significant (P≤0.05) differences for days to 85% maturity, plant height, fertile tillers per plant, unfilled spikelets per panicle and biomass yield. Higher phenotypic coefficient of variation and moderate genotypic coefficient of variation were observed for panicle shattering. Moderate to high broad sense heritability was observed for days to 85% 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 meter square and plant height. Among the studied traits total tillers per plant, fertile tillers per plant, panicles per meter square, 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 85% maturity, panicle length, fertile tillers per plant, panicles per meter square, biomass yield and harvest index at both genotypic and phenotypic levels. Phenotypically, panicles per meter square and genotypically, harvest index exerted the maximum positive direct effect on grain yield. The present study revealed that panicles per meter square and harvest index can be considered for selection in future rice breeding program.