الفهرس 
introductionOnly 14 pages are availabe for public view
 |  | from | 128 |  |  |
| | | from | 128 | | |
Abstract
Plant breeders have extensively used and exploited heterosis to
improve seed and oil yield in sunflower. In a systematic breeding
program, it is essential to identify superior parents for hybridization
and crosses to expand the variability reservoir for selection of
superior genotypes. Combining ability analysis helped the breeder in
selecting desirable parents and provided information or the relative
importance of GCA and SCA for interpreting the genetic basis of
important traits.
The present work was carried out at Sakha Agricultural
Research Station, ARC, Egypt during the two growing summer
seasons (2009 and 2010).
The main objectives of the present investigation were:
I. To evaluate six sunflower cytoplasmic male sterility (CMS)
and four tester lines (RF) and their crosses using line x tester
analysis.
3. Estimation of combining ability and heterosis for some
agronomic traits, seed yield and oil content in parents and their
FI hybrids.
2. Estimation of genetic parameters, heritability values and
correlation coefficient.
The material used included SIX CMS lines namely; A], AIO,
A28, A2(), i\J] and A34. Also included four RF lines namely, RI, Rs, R,
and RIO. In 2009 summer season, the four restorer lines (testers)
were crossed with the six CMS lines. In 2010 summer season, the