Evaluation of Relationships between Traits and New Sunflower Hybrids Using Genotype-Trait Biplot Analysis Method

Sunflower is an important crop that its oil has high nutritional and economic value. In this study, genotype-trait biplot method was used to study interrelationships between different traits and new sunflower hybrids. For this study, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design with two replications in Gorgan Agriculture Research Station, Gorgan, north of Iran, during 2020 cropping season. The results showed that thousand seed weight, head diameter, seed number per head, stem diameter, leaf length, leaf width and petiole length had a positive correlation with seed yield. Also, a negative correlation was observed between seed yield and phonological traits and plant height. Therefore, it can be concluded that improving seed yield may simultaneously lead to improve in the early maturity and dwarfism. Based on biplot polygon view, the genotypes No. 5 and 19 had superior characteristics in terms of seed yield and its attributes. Also, based on a hypothetical ideal genotype biplot, the genotypes No. 3, 2 and 10 outranked the other genotypes in terms of all examined traits. A majority of the examined traits had high discriminating ability and were able to show differences between genotypes. The stem diameter was the nearest trait to an ideal trait and, therefore, it has the highest discriminating ability and representativeness.