Association and path coefficient analysis among grain yield and related traits in Ethiopian maize (Zea mays L.) inbred lines

Twenty four inbred lines developed by the Ethiopian National Maize Breeding Program were evaluated at Jimma Agricultural Research Center during the main season of the year 2016 in an 8 X 3 Alpha Lattice (0, 1) design with three replications. The objective was to determine the phenotypic and genotypic association among traits in Ethiopian maize inbred lines and to compare the direct and indirect effects of traits on grain yield. Analysis of variance showed statistically significant (p<0.01) differences among the tested maize inbred lines for most of the traits indicating the existence of sufficient genetic variability which can be exploited in future breeding programs. Grain yield per hectare, thousand kernels weight, ear height, ear diameter, anthesis-silking interval, and plant aspect had higher phenotypic and genotypic coefficients of variation. Grain yield showed positive and highly significant (p<0.01) genotypic association with ear diameter, number of kernels per row, days to 50% silking, number of kernel rows per ear, 1000-kernels weight and leaf width. Grain yield also had positive and highly significant (p<0.01) phenotypic correlation with number of kernels per row and ear diameter. Path coefficient analysis revealed that number of kernels per row, number of kernel rows per ear, plant height, days to maturity, 1000-kernels weight, leaf width and plant aspect had a positive direct genotypic effect on grain yield. Number of kernels per row, number of kernel rows per ear, plant height and 1000-kernels weight exerted high direct effects and also indicated positive and strong association with grain yield indicating that they can be used for indirect selection of inbred lines having higher yield potential per se. Key words: Character association, inbred lines, morphological traits, path coefficient analysis.