Genetic Variability, Phenotypic Correlation, Path Coefficient Analysis and Its Implications in Improvement of Grain Yield in Maize (Zea mays L.) Hybrids

A half diallel set of crosses among six inbred lines of maize was evaluated at the Maize Research Department, General Commission for Scientific Agriculture Researches (G. C. S. A. R.) Damascus. Governorate, during 2008 and 2009 to study gene action, narrow sense heritability, interrelationships among traits and path coefficient analysis for grain yield per plant and its components, silking date, plant and ear height. The obtained results indicated that all estimates of additive (VA) and dominance (VD) variance were significant for all characteristics, except plant and ear height, ear length and number of kernels per row. The results showed that the additive genetic variance was the major component of genetic variation in the inheritance of all traits with exception of silking date, 100-kernel Weight, grain yield per plant traits were controlled by non-additive or dominance gene action. High narrow sense heritability estimates were detected for all traits with exception of silking date, 100-kernel Weight, grain yield per plant traits which showed low narrow sense heritability estimates. Correlation coefficients among traits indicated that grain yield per plant was positively and significantly associated with 100-kernel Weight (0.480**), ear length (0.469**) and number of kernels per row (0.466**). The path coefficient results showed that each of 100-kernel Weight, number of kernels per row and ear length had high positive direct effects on grain yield.