The Genetic Analysis of Combining Ability and Estimation of Genetic Parameters for Yield and Yield Components of Sunflower by Using Cytoplasmic Male Sterility

Abstract

Seven cytoplasmic male steril lines (CMS, Feamal parents) viz., (A1, A2, A4, A6, A10, A14, and A23) and 3 tester restorers (male parents) which contains genes of fertility restoration and had mute- head ( R- line) viz.,( R1, R2, and R3) of sunflower were used in a ( line x tester ) mating system in spring season 2010, to produce 21 hybrids. The genotypes seed (10 parents + 21 hybrids) were planted in the Field Crops Research Station of State Board of Agricultural Research - Abu Ghraib by using RCB design with three replicates in fall season 2010. The objective of this study was to identify and select superior sunflower lines based on their performance as well as to evaluate their single cross hybrid performance based on results of genetic analysis of combining ability, and some genetic parameters. using Line x tester analysis. The studied traits were head area, fertility ratio 100 seed weight, yield of seed per head, oil ratio and oil yield. The Results of genetic analysis showed that the mean square of general combining ability (GCA) and specific combining ability for hybrids (SCA) was high significant differences in all studied characters indicating the importance of both additive and non additive gene actions in the control of these characters. The parent A1 showed high GCA effect in head area (19.09) and parent A2 in fertility ratio(2.92) and oil yield (3.44). parent A23 showed high GCA effect in number of seed per head(117.1) and seed yield (13.07),while the tester R2 showed high GCA effect in 100 seed weight, fertility ratio and seed yield per head(31.49). Hybrid (A1x R1) showed high SCA effect in number seed per hesd(92.70),nad hybrid A1 x R2 in fertility ratio(3.52) and 100-seed weight (1.32).Hybrid (A1xR3) showed high SCA effect in oil ratio(3.52), while hybrid (A2xR2) showed high SCA effect in oil yield (3.35). hybrid (A10xR3) showed SCA effect in seed yield (7.23).hybrid(A23 x R1) shwed SCA effect in head area (35.34). The ratio of effect variance of general combining ability σ²gca to the specific combining. ability 2σ sca were less than one for all studied traits. The estimates of the average degree of dominance were greater than one for all studied traits which except the head area was negative value, indicating to be that these traits were controlled by dominance effects, and this reflects the reduction of the values of the narrow sense heritability for all studied characters. .