Abstract:
Rice (Oryza sativa L.) is one of the most important staple crops in the world, serving as a
primary source of food for over half of the global population, though it has relatively short
history of production and research in Ethiopia. Hence, genetic improvement is of paramount
importance to increase the production and productivity of the crop, which requires
understanding of genetic variability in the crop. The study was conducted during 2023/2024
main cropping season at Pawe Agricultural Research Center, Ethiopia, to determine the
magnitude of genetic variability and interrelationships of yield and yield related traits in 80
upland rice genotypes.in an alpha lattice design with two replications, focusing on genetic
analysis of variance showed significant differences among genotypes for 12 traits such as DH,
DM, PH , PL, NPT ,NFGPP, BM, HI, TSW, SW and GSP .The highest genotypic variation (12.85) and
phenotypic variation (20.51) was recorded for the number of productive, tiller per plant while
the lowest GCV (0.96) and PCV (1.44) was recorded for days to maturity. Broad sense
heritability value ranged from 80.18% for plant height to 29.51% for seed width. High genetic
advance as a percent of the mean was observed for the number of productive tillers, plant height,
grain yield, and thousand seed weight, indicating the presence of additive genes, making
selection based on these traits successful. The highest positive correlations with grain yield were
found for harvest index, biomass, and number of fill grains per panicle at both genotypic and
phenotypic levels (r = 0.829, r = 0.541, r = 0.439). These indicated that improving upland rice
through selection would be effective considering these traits. Path coefficient analysis revealed
the maximum positive direct effect of harvest index and biomass yield on grain yield, indicating
that considering these traits during the selection of rice genotypes would be more rewarding in
evolving potential varieties of upland rice. The first five principal components with Eigen values
greater than one accounted for 77.23% of the total variation among genotypes. Cluster analysis
showed that genotypes were grouped into five clusters with the maximum inter-cluster distance
between clusters IV and II (D2 = 2813.08), while the minimum inter-cluster distance was
between clusters II and V (D2 = 574.91). Six rice genotypes with grain yield above 57.5 - 61.9
qt/ha-1 have been identified and based on the data for future breeding program that employ
hybridization, parental material selection should be carried out between clusters rather than
within clusters