Diallel analysis of maize inbred lines for estimating superiority and combining ability

Abstract

The phenomenon of heterosis has provided the most important genetic tools for crop yield improvement. Identification of specific parental combinations capable of producing the highest level of heterotic effects in F1 has immense value for commercial exploitation of heterosis. The objective of this study was to assess the combining ability variances and superiority in twenty one combinations developed by crossing seven maize (Zea mays L.) inbred lines in half diallel fashion design. The resulting 21 hybrids, along with two check hybrids, were evaluated in Randomised Complete Block Design, in three locations during 2022 season in Egypt. The results showed that both additive and non-additive gene actions were important in controlling all the measured traits. The General Combining Ability (GCA) variance was found to be greater than Specific Combining Ability (SCA) variance, indicating predominance of additive and additive by additive gene effects in the inheritance for all studied traits. Cross P2×P3 significantly out yielded the best check (SC. 168) for the grain yield trait. The parental inbred lines, P1, P2 and P3, possessed significant desirable (GCA) effects for the grain yield trait. The cross combinations (P1×P5),(P2×P7), (P3×P7),(P4×P5),(P4×P6) and (P6×P7) showed significant positive sca effects for grain yield. Cross P2×P3 (10.32**) obtained superiority (%) relative to the check hybrid SC.168 for grain yield. On the other hand, five crosses viz. (P1×P3), (P1×P5), (P2×P3), (P2×P5) and (P3×P5) expressed positive superiority (%) over the check hybrid SC.3444 for same trait. Thus, these crosses could be recommended to be released as commercial hybrids by Maize Research Programme after further evaluation and testing in multi-locations in Egypt.