Selection among S₃ maize lines (Zea mays L.) using testcrosses [electronic resource].

Includes references.

Nineteen white maize lines (S3) derived from different exotic hybrids in the disease nursery field were crossed to each of two elite inbred tester lines Sd 7 and Sd 34 in 1998 season. The resultant 38 testcrosses along with two check commercial hybrids SC.10 and SC.l24 were evaluated in field trials at Sakha, Gemmeiza and Sids Agric. Res. Stations during 1998 season. Data for grain yield//fed, days to mid silking, plant height and ear placement (%)were recorded tn estimate combining ability effects, type of gene action and select the most superior lines and crosses. Combined data over locations indicated that highly significant differences were detected among lines, testers and their crosses for all studied traits. except days to mid silking for testers and lines x testers interaction. The best general combiner of parental lines were L-5, L-6 L-7, L-10. L-13 and L-14 for high yielding ability, L-5 for high yielding ability and earliness to silking, and L-6 and. L-13 for high yielding ability and short plant statues. The most superior cross (L-14 x Sd.34) possessed highiy significant and positive SCA effects and manifested significantly out yielded (36. 77 ard/fed) the best commercial hybrid SC.10 (34.51 ard/fed) by 6.5 %. Also, this cross was insignificantly different from SC.10 for the other studied traits.

Summary in Arabic.

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