Combining ability and type of gene action in maize under favorable and water stress environments [electronic resource].

Includes references.

Thirty five yellow S1, lines of maize were top crossed to three testers: the base population pop-45, single cross-l56 and SC-159. The 105 top crosses were evaluated under water stress and non-stress (favorable) environments to estimate combining ability and type of gene action for grain yield and other agronomic traits. Highly significant differences were found among crosses, lines and 6ne x tester (LxT) interaction for all studied traits under both environments. Combined analysis showed significant mean squares for environments (E), LxT, LxE, TxE and LxTxE interactions for II10St of tile studied traits. The magnitude of σ 2 GCA and σ 2 SCA were high for most of the studied traits under water stress than under non-stress environment. The magnitude of σ 2 SCA was larger than σ 2 GCA for all studied traits under both environments, indicating the importance of non-additive gene effects in the inheritance of the studied traits. The variance of interaction between σ 2 GCA x E was high than that of σ 2 SCA x E for all studied traits. The yellow S1 lines no. 7 and 22 showed significant and positive GCA effects for grain yield under both environments. The S1, lines no. 4, 30, 36 and 113 under favorable and no. 3, 18, 27, 28, 31, 33, 83 and 229 under water stress environment showed Significant and positive GCA effects for grain yield. These lines sbould he directly utilized in breeding programmers to develop high yielding hybrid(s). Results sbowed that 14 and 11 top crosses showed significant and positive SCA effects for grain yield under non-stress and water stress environments, respectively. Key words: Maize, Combining ability, S1 lines, Gene action, Water stress.

Summary in Arabic.

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