DETERMINING COMBINING ABILITY OF SOME NEWLY DEVELOPED YELLOW MAIZE INBRED LINES USING LINE X TESTER DESIGN

Twelve yellow maize inbred lines were crossed with two testers in line × tester mating design to produce 24 hybrids at Sakha Agricultural Research Station in the 2019 growing season. These 24 F1 hybrids along with two commercial check hybrids were evaluated in the 2020 season at three research stations (Sakha, Gmmeiza and Mallawy). The mean squares due to locations, crosses, and their interaction was highly significant for studied traits. Also, the mean squares due to lines, testers, and line x tester interaction were significant or highly significant for most traits. The data of days to 50% silking, plant height, ear height, and grain yield were recorded. The four inbred lines L-5, L-6, L-8, L-12, and tester Gz-666 were the best combiners for earliness. Whereas, inbred lines L-3, L-4, L-9, and tester Gz-658 were the best general combiners ability for grain yield. The best hybrids for specific combining ability were L-5×Gz-666 and L-11xGz-658 for grain yield. Additive and non-additive gene effects have a greater role in the inheritance of days to 50% silking, plant height, and ear height but the major role attends to additive gene effect. Meanwhile, non-additive gene effects have a major role in the inheritance of grain yield. The cross L-9 x Gz-658 is the best cross for grain yield and significantly out yielded the commercial checks and recommended further evaluation on large scale.