الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 160 |  |  |
| | | from | 160 | | |
Abstract
The aims of this study were studying number of genotypes to select the suitable parents to use them in crosses to improve the traits or to produce a new variety.The studied traits were, seed cotton yield/plant (S.C.Y./P. gm), lint cotton yield/plant (L.C.Y./P. gm), lint percentage (L. %), boll weight (B.W. gm), number of bolls/plant (No.B./P), seed index (S.I. gm), earliness index (E.I), lint index (L.I. gm) as yield and yield component traits; fiber length at 50% span length and 2.5% span length (50% S.L. mm and 2.5% S.L. mm), fiber fineness (F.F. units), fiber strength (F.S. Pressely index) and uniformity ratio (U.R. %). The obtained results of this study could be summarized in the following points:* Analysis of variance of genotypes, parents and crosses were significant for most studied traits during the two years as well as the combined data. The differences due to genotypes, parents and crosses (lines, testes and line x tester interactions) by years were significant for most studied traits, indicating that these sources showed different performances with different environmental conditions.* The mean performances for the line Giza 86 and the testers Pima S6 and R. 6022 were the highest for most studied yield and yield component traits. However, for fiber traits, the lines Giza 89, Giza 45 and Giza 70 and the testers Pima S6 and Karshenky were the highest parent for most fiber traits.* Most of the F1 crosses were exceeded their corresponding parents, where most of the combination which had Giza 89 and Karshenky among their parents were the highest yielding. The best for fiber quality properties were these which had Giza 45, Giza 88 and C.B. 58. * Significant heterosis values over mid and betterparents were detected for most studied traits. The following crosses were exhibited the highest values of heterosis versis better parent i.e., Giza 89 x C.B. 58 for seed cotton yield/plant in gram and lint cotton yield/plant in gram with the values of 69.5% and 71.5%, respectively, Giza 89 x R. 6022 for lint percentage with the value of 6.1%, Giza 85 x C.B. 58 for boll weight in gram with value of 37.5%, Giza 75 x C.B. 58 for number of bolls/plant and 50% span length in mm with values of 40.8% and 21.1%, respectively, Giza 86 x Pima S6 for seed index in gram with value of 13.3%, Giza 85 x Pima S6 for earliness index with value of 37.3%, Giza 86 x Karshenky for lint index in gram with value of 20.3%, Giza 75 x Pima S6 for 2.5% span length in mm and fiber fineness (units) with values of 8.5% and 20.3%, respectively, Giza 89 x Pima S6 for fiber strength (Pressely index) with value of 12.6% and Giza 70 x Australian 13 for uniformity ratio with value of 4.12%.