الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 123 |  |  |
| | | from | 123 | | |
Abstract
The present investigation was carried out at the field of Sakha, Gemmeiza and Sids Research Stations, Agricultural Research Center (ARC) during 1999 growing season. The main objectives were to identify general and specific combining abilities, heterosis, types of gene action and components of genetic variation for vegetative traits, grains yield and its component traits of parental inbred lines and their single crosses under three environmental conditions. ?Genotypes by environments (locations) interactions were significant in case of number of days to 50% silking date, plant height and number of ears/plant. Parental lines and checks were significantly interacted with locations in case of silking date and number of ears per 100 plants. The mean squares due to the interaction of F1 crosses with locations were also significant for all studied vegetative traits, except ear height. All crosses possessed valuable positive and highly significant estimates of heterosis and heterobeltiosis toward the longest ears, the thickest ears, more number of rows/ear and more number of grains/row. Highly significant differences were detected among the studied genotypes (parents, F1 crosses and checks). The source of variation due to parents, F1 crosses, checks, parents vs crosses and crosses vs checks were highly significant for the three studied traits. The best SCA effect for grain yield was exhibited in crosses between parents with good (Sd7 and Sd34) and poor (Gm18, Gz628 and Sk7041) GCA, i.e. (Sd 7 x Gm 18), (Sd 34 x Gz 628) and (Sd 34 x Sk 7041).