Combining Ability of Agronomic Traits in Sunflower (Helianthus annuus L.) Using Line X Tester Analysis

Eight lines and six testers of sunflower were crossed using line x tester method. The 48 F1 single cross combinations along with their parents and two checks were planted in simple lattice design with two replications. The results of analysis of variance showed significant differences among the genotypes for all the traits including plant height, head diameter, life-cycle duration, grain yield, 1000 seed weight, oil content and oil yield. Line x tester analysis revealed significant effects of genotypes, hybrids and interaction effects of line x tester for all the studied traits. The testers including RF81-25 and RF81-30 with significant positive general combining ability (GCA) effects for grain yield and 1000 seed weight respectively and also RF-131/1 with significant negative GCA effect for plant height were considered as good combiners and also the lines including AF80-488/1/2/1 and AF80-488/2/1/1 were good combiners for grain yield and 1000 seed weight respectively. The crosses including AF80-460/2/1/1 x RF81-25 and AF8-6937 x RF81-30 had significant positive specific combining ability (SCA) effects for grain yield, oil content and oil yield. Estimating low narrow sense heritability for all the traits indicating the importance of non additive genetics effects for them, so for improving these traits hybrid method will be effective.