Evaluation of newly improved inbred lines of maize and its testers for combining ability [electronic resource].

Includes references.

The inbred line Gz 603, the male parent of single cross 122 (SC 122) and single cross 124 (SC 124) was crossed to tbree non-recurrent parents, i.e. Gz 601 Gz 602 and Gz 604. These non-recurrent parents along with the recurrent parent (Gz 603) were derived from the cross between inbred line Sids 7 (Sd 7) and an elite corn belt inbred B73. The three F1 crosses, i.e. Gz 601 x Gz 603, Gz 602 x Gz 603 and Gz 604 x Gz 603 were backcrossed to Gz 603 for three successive generations before selfing once followed by selection in each generation for heat tolerance and increased production of pollen grains as well as grain yield and other attributes of agronomic value. Twenty-five modified lines were testcrossed to two testers, i.e., Gz 628 and Gz 629. the female parents of the released single crosses 122 and 124. respectively. In 1998 summer season, the fifty topcrosses along with two checks (SC 122 and SC 124) were evaluated in replicated field trails at three loCations, i.e., Sakha, Gemmeiza and Sids. The obtained results revealed that both lines and testers were significantly differed for all stuctied traits. except late wilt resistance in the combined data over locations. The interactions of lines x locations, testers x locations, lines x testers and topcrosses x locations were highly significant for days to 50% silking and grain yield in ardab/fad.

Summary in Arabic.

1