Inheritance of grain yield and its components in line by tester method of maize (Zea mays L.)

This study was carried out at the Scientific Agriculture Research Center, Al-Ghab, Syria, during 2013 –2014 growing seasons to estimate heterosis, combining ability, phenotypic correlation and path analysis for plant and ear height, ear length, eardiameter, number of rows per ear, number of kernels per row, 100 kernel weight and grain yield per plant for eighteen hybrids produced by the line × tester method, the major findings were: inbred lines, testers, hybrids and combining ability mean squares were significant for all traits, indicating that additive and non-additive gene actions were the important in inheritance of all traits. The ratios of σ2 GCA/σ2 SCA showed that non-additive gene action was more important in controlling all traits except of number of kernel per row. Heterosis percentage for all traits were significant compared with the check variety except of ear height trait. GCA effects showed that the lines P1 and P7 were good combiners for grain yield per plant, also, SCA effects showed that P2×P8, P5×P8, P4×P9 and P1×P7 crosses were the best F1 combiners for grain yield per plant. Results of phenotypic correlation and path analysis values showed that ear length, ear diameter and number of kernel per row were positively and significantly associated with grain yield per plant, also, these traits can be considered as selection criteria may lead to the improvement of grain yield in maize.