Abstract
Six sun flower Genotypes (1-American, 2-Argenteny, 3-Govan, 4-Azor, 5-Mungreen, 6-Louse. were planted. half diallel was conducted out to get F1, In the next season the F1 seeds were planted to get F2.In the third season the six parents and all their F2 were planted in randomized complete block design with three replications.to study general and specific combining abilities for parents and crosses respectively, phenotypic variance components and some genetic parameters for parents and crosses were determined for plant height, leaf area, no. of seeds\head, diameter of head, 1000 weights seed, seed yield, biological yield, dry weight. Results indicated that the analysis of variance for genotypes, general and specific combining ability were significant for leaf area and No. of seed head and biological yield. While specific combining ability were specified for 1000 seed weight, seed yield and diameter head. The values of broad sense heritability was ranged from 67% for plant height character and 99% for leaf area and biological yield characters. Narrow sense heritability ranged from 1% for plant height and 40% for Biological yield. It was shown that selection for Biological yield gave higher percent of response to selection (27.12%) from original mean of yield, followed by no. of seed /head which gave percent of response to selection (15.62%)from original mean of yield.
