Evaluation of combining ability and genetic components in sunflower

Abstract

Evaluation of genetic material involved in breeding proces is of great importance in order to choose the most valuable genotypes with ability to efficiently combine desirable genes in progeny. The objective of this study was to utilize diallel method in order to estimate mode of inheritance, heterosis effect, combining abilities and components of genetic variance for important properties in sunflower and to identify those genotypes that can make progress in sunflower breeding. Present research had been carried out during 2012 and 2013 growing seasons. Evaluation included 6 sunflower genotypes and their 15 combinations which were crossed according to incomplete diallel. For seed yield/plant dominance of better parent (d+) was expressed as a mode of inheritance, while regarding thousand seed weight the most common modes of inheritance were dominance (d+) and partial dominance of better parent (pd+). The most common mode of inheritance regarding oil content was superdominance (sd+). Empirical estimates of combining abilities of genotypes involved in breeding process is main startegy in evaluation of breeding value. Regarding seed yield/plant significant and positive heterosis effect (28.9%) was calculated in combination Harkovski x Rodnik (P3xP5), while the highest heterosis effect for oil content (12.8%) was determined in combination Harkovski x Amaian (P3xP6). Combining ability analysis indicated that both genetic components, additive and non-additive, were important in expression of investigated traits. Components of genetic variance indicated prevalence of dominant component (H) compared to additive (D) and higher concentration of dominant genes (u) compared to recessive (v), in all investigated traits.