Combining Ability and Heterotic Groups of New White Maize Inbred Lines

: A field experiment was conducted during two seasons. In 2022 summer season, sixteen new white maize inbred lines were crossed with three testers using (Line x Tester) method. The result for 48 F1 crosses plus two standard check were evaluated in 2023 summer season at three Research Stations, Sakha, Gemmiza and Mallawi. The recorded data were days to 50% silking, plant height (cm), ear height (cm) and grain yield (ard/fad). Mean squares due to locations (Loc), lines (L), testers (T), (L × T), (L × Loc), (T x Loc) and ( L × T × Loc) interactions were significant, except Loc for grain yield and (L × T × Loc) for plant height. Single crosses (Sk.5009/40 × Sd.7), (Sk.5009/41 × Sd.7) and (Sk.5009/42 × Sd.7) were significantly outyielded the check. Five inbred lines (Sk.5009/40), (Sk.5009/41), (Sk.5009/42), (Sk.5009/43) and (Sk.5009/44) showed desirable General Combining Ability (GCA) effects for grain yield. Also, inbred lines (Sk.5006/34) and (Sk.5006/35) showed desirable GCA effects for earliness, plant height and ear height. Ten crosses showed positive Specific Combining Ability (SCA) for grain yield. The cross (Sk.5009/42xSd.7) showed desirable SCA effects for all traits. The tested inbred lines based on heterotic groups were classified to three heterotic groups. Group-1 (Tester Sd.7) included inbred lines (Sk.5006/34), (Sk.5006/36), (Sk.5006/38), (Sk.5009/45), (Sk.5010/47), (Sk.5010/48) and (Sk.5010/49) while group-2 (Tester Sd.63) included only inbred lines (Sk.5006/35). Group-3 (Tester Sc.131) included (Sk.5006/37), (Sk.5008/39), (Sk.5009/43) and (Sk.5009/46). These groups help breeder to choose best parents to create superior crosses.