الفهرس | Only 14 pages are availabe for public view |
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 |