Genetic Behavior and Relative Importance of Some Morpho-physiological andYield Components in Relation to Grain Yield in Maize ( Zea mays L. )

The present study was undertaken to study the gene action, narrow sense heritability, interrelationships among traits and path coefficient analysis for grain yield and its components, silking date, plant and ear height, leaf area index (LAI), specific leaf weight (SLW) and specific leaf area (SLA). Fifteen hybrids produced using a half diallel fashion in 2008 season were evaluated for grain yield and its components and morpho- physiological traits during 2009 season. The obtained results indicate that all estimates of VA and VD were significant for all traits except VA for specific leaf weight and ear length. In addition, VD for grain yield per plot, leaf area index, specific leaf weight, plant height, ear length, ear diameter, number of rows per ear and number of kernel per row. However, the magnitude of VA was consistently larger than that of VD for all traits. High narrow sense heritability estimates were detected for leaf area index (93%), leaf angel (90%), plant height (90%), ear height (89%), ear length (89%), number of rows per ear (89%) and number of kernel per row (83%). However, moderate narrow sense heritability estimates were obtained for grain yield per plot (77%), one hundred kernel weight (77%), silking date (74%), ear diameter (74%), specific leaf area (64%) and specific leaf weight (55%). While it was very low for stay green (5%). These results indicate the importance of choosing the suitable segregating generations for exhibiting the best expression of gene of different studied traits. Correlation coefficients among traits indicated that grain yield was positively and significantly associated with ear diameter (0.788**), one hundred kernel weight (0.747**), ear length (0.600**), specific leaf weight (0.518**), leaf area index (0.466**), number of rows per ear (0.458**), plant height (0.408**), number of kernels per row (0.361*) and silking date (0.351*). The path coefficient analysis was calculated to detect the relative importance of characters contributing to grain yield per plot. Data show that each of ear diameter, one hundred kernel weight and ear length had high positive direct effects on grain yield per plot.