Inheritance of grain yield and oil content in new maize high oil single-crosses [electronic resource].

Includes references.

Fourteen yellow maize inbred lines derived from different segregating generations of Pop. Sk-21, Pop.59£ and local open pollinated variety were top crossed to each of three inbred tester lines ,T-I, T-2, and T-3, which were derived from Iowa High Oil Syn#1 (c.1934), lowa high Oil Syn#2 (B.1935) and a local variety, respectively at South Valley Agric. Res.. Station, Toshka region under drip irrigation system in 2003 season. Top crosses were evaluated in field trials at Sakha and Sids Agrie. Res. Stations during 2004 season. Data for grain yield. oil percentage and oil yield were collected to estimate the combining ability effects, type of gene action and select the most superior promising single cross(es). Results indicated that significant of mean squares were detected due to the top crosses parental inbred lines, tester lines and line x tester interactions for the three traits at each location and for their combined analysis, except tester lines at each location and combined across locations as well as parental inbred lines at Sids for oil yield. However, combined data over the two locations indicated that 9 out of the 42 single crosses i.e. (L-I x T-I). (L-5 x T-I). (L-8 x T-I), (L-II x T-I), (L-2 x T-2), (L-II x T-2), (L-I x T-3), (L-IO x T-3) and (L-13 x T-3) manifested significantly higher oil% and oil yield by at least 2.1 times than the three commercial single crosses. In the same time, these crosses, except (L-I x T-I) and (L-2 x T-2) did not differ insignificantly in grain yield from the best commercial single cross (SC Pion3084). These crosses should be further tested for possible commercialization to improve maize productivity and oil content. Also. they might be of interest in the national breeding program for developing good new high oil inbred lines and/or composite varieties. The best general combiner in the combined data across locations were obtained from 4, 5 and 3 parental inbred lines toward high groin yield, high oil (%) and high oil yield. respectively. Moreover, one of them (L-I) could be considered the best combiner for the three studied traits. The highest desirable SCA effects resulted from 12, 13 and 5 top-crosses for the previous three traits, respectively. However, the top crosses (L-2 x T¬2), (L-9 x T-2). (L-IO x T-3) and (L-13 x T-2) had the best specific combining ability for the three studied traits. The magnitude of dominant genetic variances was considered to he the major source of the total genetic variance responsible for the inheritance of the three studied traits at both locations and combined over locations, except groin yield at Sakha. Key words: Maize, Top-cross, Combining ability, Grain yield, Oil content.

Summary in Arabic.

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