Genetic variation, heritability, genetic advance and agronomic character association of yellow elite inbred lines of maize (Zea mays L.)

Fifteen elite yellow maize inbred lines were evaluated in a randomized complete block design experiment with three replicates in 2014. Data were collected on days to anthesis and silking, anthesis-silking interval, plant and ear heights, number of ears per plant, leaf area, ear weight and grain yield. Mean values were used to determine characters' phenotypic and genotypic variances, phenotypic, genotypic and environmental coefficients of variation. Broad sense heritability and genetic advance percentage of mean were estimated for each trait. Significant variation existed in all the characters. The coefficients of variation were low except for ear weight and grain yield that were relatively higher. The anthesis-silking interval was highest in lines TZEI 124 and TZEI 16, but least in lines BD74-222, TZEI 11 and TZEI 13. Line BD74-222 had the height plant height and BD74-165 had the least. Line TZEI 124 produced highest maize grain yield whereas line TZEI 146 had the least. Coefficients of variation of phenotype and genotype were low for all the traits except number of ear per plant, ear and grain yield. The characters were less influenced by the environment thus the traits can be used for selection. Heritability was greater than 80% for all characters studied whereas expected genetic advance ranged from low (8.91) in days to silking to high (72.03) in number of ear per plant. Days to anthesis and silking, plant height and number of leaf per plant were positively correlated. Grain yield was positively correlated with ASI, plant and ear heights, number of leaf per plant and leaf area. High heritability and high genetic advance for ASI indicated the presence of additive genes in the trait and suggested reliable maize improvement through selection of the traits. In this study moderate genetic advance was associated with high heritability.