Evaluation of Combining Ability and Heterosis of Phenological and Morphological Traits and Seed Yield in Breeding Lines of Sunflower using Line×Tester Analysis in Summer Cropping Condition

Combining ability and heritability of yield and yield components of sunflower(Helianthus annuus L.) breeding lines was studied using line × tester analysis. Eightlines and six testers which were tolerant to plasmopara (Plasmopara halstedii) diseasewere crossed in line × tester method. 48 F1 single cross combinations along with theirparents and two checks including Azargol and SHF81-85 were planted in simple latticedesign with two replications. The results of analysis of variance revealed significantdifferences among the genotypes for all the traits including plant height, life-cycleduration, duration of flowering, grain yield, seeds per head and oil yield. Line × testeranalysis based on Comstock and Robinson design II displayed significant effects ofgenotypes, parents and hybrids for all the studied traits. For growth period, RF81-25,AF80-488/1/2/1 had significant negative general combining ability effects. For durationof flowering, RF81-30, AF80-533/1/1/1 had also significant negative general combiningability effects. For seeds per head, RF81-25, AF80-488/1/2/1 and also for seed yield andoil yield, RF81-150/1 and AF80-488/1/2/1 maintained significant positive generalcombining ability effects. The crosses including AF80-460/2/1/1× RF81-25 and AF-6937×RF81-30 had significant positive specific combining ability for seed and oil yield.Maximum heterosis effects for seed yield were belonged to AF80-960×RF81-25.