Heritability and Genetic Gain in Maize


This research was conducted at the farms of the Dept. of Field Crop Science/ College of Agriculture/ University of Baghdad, during two seasons of 2004. The objective of the study were to assess genetic variance for some characters of maize (Zea mays), and their contribution to yield variation; and the correlation among characters in addition to the heritability and genetic gain of four selection criteria based on the highest yield, harvest index, grain weight, and grain per ear according to each criteria, 100 plant grain seeds were selected and mixed. During fall seasons seeds were distributed among treatments in four replicates according to RCBD whine a split plot arrangements.The characters grain number per ear, dry weight and yield efficiency contributed to the whole yield variance (1998.77) by 27.27 and 270% respectively. These characters gave the highest heritability (0.49, 0.49 and 0.48) and the highest genetic gain (64.15, 64.09 and 63.32) respectively. Phenotypic variance was higher than genotypic for all characters under study. There was a positive genetic correlation between grain yield and other characters. The highest correlation coefficient was found with yield efficiency (0.901), dry weight (0.884), grain number per ear (0.853) and ear number per plant (0.788). The phenotypic correlation was also high (0.84, 0.661, 0.835 and 0.781 respectively). Yield was not significantly correlated with leaf area index (0.085, 0.004, 0.047, 0.0359 and 0.038) respectively. All genotypic values were higher than phenotypic, for phenotypic is controlled by genotype.