Top-crosses analysis for selecting maize lines in the early self generations [electronic resource].

Includes references.

Twenty selected 53 white maize lines derived from the wide genetic base population Composite-S (Cycle-3), were topcrossed to each of two white maize inbred testers, i.e. Sd 7 and Sd 63. The 40 topcrosses were evaluated in 2000 growing season at Gemmeiza and Sids. Agric. Res. Stations. The data were abdalned for grain yield, number of ears/plant, resistance to late wilt disease, silking date, plant height and ear height. Testers contributed much more than the lines to the total genetic variation and were more affected by the environmental conditions. The inbred.testers ranked the 20 lines differently. Parental lines L-4, L-9, L-11, L-13, L-14, L-17, L-19 and L-20 were found to be the best general combiners for high yielding ability. L-11, L-13, L-14, L-15 and L-19 were significantly better general combiners for prolificacy. Parental females L-7, L-9, L-12 and L-13 were good donors for resistance to late wilt disease. Meanwhile, L-11, L-13, L-15, L-16, L-17, L-18, L-19 and L-20 were significantly better general combiners for earliness, as well as, L-2, L-7 and L-15 were good donors for shortness and lower ear placement. Inbred tester Sd 7 manifested highest average performance of grain yield compared to testcrosses of Sd 63. Key words: Maize, Tester, Inbred, Testcross, Combining ability, Variance.

Summary in Arabic.

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