Use of Selection Index of Ideal Genotype (SIIG) in Order to Select New High Yielding Sunflower Hybrids with Desirable Agronomic Characteristics

Production of high yielding hybrid cultivars is the main objectives of breeding programs in sunflower. Therefore, the selection of high yielding hybrids is essential in this plant. In this regard, 24 new sunflower hybrids and Golsa cultivar were evaluated in a simple lattice design with two replications in the Gorgan Agricultural Research Station during 2020 cropping season. In this study, the selection index of ideal genotype (SIIG) and factor analysis was used to select new sunflower hybrids and finding interrelationships among them. Based on the SIIG index, the genotypes G5, G10, G2, G12, G3 and G19 with the highest SIIG values (0.747, 0.689, 0.660, 0.641, 0.640 and 0.572, respectively) were the best genotypes. On the other hand, G23, G15, G24, G25 and G18 genotypes with the least amount of SIIG value (0.233, 0.264, 0.277, 0.278 and 0.285, respectively) were the weakest genotypes for most studied traits. The genotypes of G5, G19, G2, G10, G3, G9 and G11 with high SIIG value and higher seed yield that total average were recognized as superior genotypes from the point of yield and other agronomic traits. Therefore, these genotypes can be used for further testing, including adaptation tests in warm wet areas. Also, the results of factor analysis indicated a positive relationship between stem diameters, head diameter and seed number per head with seed yield. Generally, it can be concluded that traits of stem diameter, head diameter and seed number per head could be used as suitable criteria in selecting for increased seed yield in sunflower breeding programs.