Simultaneous Selection for Seed Yield and Agronomic Traits in Sunflower

Selection of high yielding genotypes is very important in sunflower. Thus, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design (5×5) with two replications in the Agriculture Research Station of Gorgan, north of Iran, during 2020. The genotype by yield × trait (GYT) biplot method was used in order to study the relationships between different traits and to select the new hybrids of sunflower based on yield-trait combinations. The result of polygon view of GYT biplot indicated that G19 was the best genotype in terms of the combination of seed yield with traits such as stem diameter, head diameter, seed number per head, thousand seed weight, early maturity and leaf number. Similarity, G5 also was superior genotype in terms of the combination of seed yield with a number of traits, including plant height, head height from ground level, leaf length, leaf width and petiole length. Based on average tester coordinate (ATC) view of GYT biplot, the genotypes G19 and G5 in terms of all positive yield-trait combinations were recognized as the best genotypes and genotypes G24, G23 and G25 as the weakest genotypes. A significant positive correlation was observed between seed number per head, thousand seed weight and early maturity in combination with seed yield. Moreover, these traits had high broad sense heritability. Therefore, it seems that traits such as seed number per head, thousand seed weight and early maturity could be used as suitable selection criterions for increasing seed yield in sunflower.Selection of high yielding genotypes is very important in sunflower. Thus, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design (5×5) with two replications in the Agriculture Research Station of Gorgan, north of Iran, during 2020. The genotype by yield × trait (GYT) biplot method was used in order to study the relationships between different traits and to select the new hybrids of sunflower based on yield-trait combinations. The result of polygon view of GYT biplot indicated that G19 was the best genotype in terms of the combination of seed yield with traits such as stem diameter, head diameter, seed number per head, thousand seed weight, early maturity and leaf number. Similarity, G5 also was superior genotype in terms of the combination of seed yield with a number of traits, including plant height, head height from ground level, leaf length, leaf width and petiole length. Based on average tester coordinate (ATC) view of GYT biplot, the genotypes G19 and G5 in terms of all positive yield-trait combinations were recognized as the best genotypes and genotypes G24, G23 and G25 as the weakest genotypes. A significant positive correlation was observed between seed number per head, thousand seed weight and early maturity in combination with seed yield. Moreover, these traits had high broad sense heritability. Therefore, it seems that traits such as seed number per head, thousand seed weight and early maturity could be used as suitable selection criterions for increasing seed yield in sunflower.