Combining Ability of White Maize Inbred Lines Via Line X Tester Analysis

Abstract

Combining ability analysis was conducted using line x tester design for seven inbred lines of maize which were crossed to three single crosses as testers at Ismailia Agricultural Research Station during 2016 growing season. In 2017 season, 21 crosses in addition to one check hybrid were evaluated at three locations. Highly significant differences were found between the locations for all studied traits. Mean squares due to crosses, their partitions and their interaction with locations were significant or highly significant for all studied traits, except for lines and lines x testers for number of ears/plant and testers for number of rows/ear. The best inbred lines for general combining ability effects were Gz-8093, Gz-8092 and Gz7253 for earliness and Tep6240 for grain yield. the tester SC 131 was the best general combiner for days to 50% silking toward earliness, grain yield, number of ears/plant, ear length and ear diameter. The cross Gz-8093 x SC131 had the desirable SCA effects for all traits also. The additive gene effects were more important than the non-additive gene effects in inheritance of days to 50% silking, number of ears/plant, ear length and ear diameter while, the non-additive was more important than additive for grain yield, number of rows/ear and number of kernels/row. The nonadditive gene effects were more affected by environment than additive gene effects for all traits except for number of ears/plant. The cross Gz-8093 x SC131 highly significantly outyielded to the TWC 324, suggesting the use of this cross in maize breeding programs.