CLASSIFYING NEW MAIZE INBRED LINES INTO HETEROTIC GROUPS USING THREE METHODS

doi:10.12816/ejpb.2024.366447

CLASSIFYING NEW MAIZE INBRED LINES INTO HETEROTIC GROUPS USING THREE METHODS

Document Type : Original research

10.12816/ejpb.2024.366447

Abstract

Identification of distinct heterotic groups should help development of outstanding hybrids and improve the efficiency of hybrid development program. Twenty-two new yellow maize inbred lines were crossed with two inbred testers using line × tester mating design in 2022 growing season. The resulting 44 F₁'s plus one commercial hybrid were evaluated in 2023 growing season at three locations (Sakha, Gemmiza and Mallawi Agricultural Research Stations) in a randomized complete block design with three replications for traits; days to 50% silking, plant height, ear height, ear length and grain yield. The mean squares due to lines (L), testers (T), lines × tester (L×T) and their interactions with locations (Loc) were significant or highly significant for all studied traits except for plant and ear heights of (L×T×Loc) interaction. The additive gene effects were preponderant in the inheritance of all studied traits, except for grain yield, where the non-additive gene effects played more important role. The best inbred line for general combining ability (GCA) effects was L1 for earliness and short plant and ear heights, L7 for longest ear and L20 for high grain yield. The cross (L15×Gz658) significantly out-yielded the commercial check SC168. The three heterotic group methods were differed in identifying the superior hybrids obtained from parents selected from different groups. Heterotic grouping based on combining ability effects (HCAE) method was the best for identifying the superior hybrids followed by heterotic grouping based on specific and general combining ability effects (HSGCA) method; also HCAE identified the lowest number of the superior crosses obtained from parents within the same heterotic group followed HSGCA method. Hence HCAE was the most efficient methods for grouping the inbred lines followed by HSGCA than SCA effects method.

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