Comparison of genotype × trait and genotype × yield-trait biplots in Sunflower cultivars

The selection of genotypes based on various characteristics is a critical challenge in plant breeding. An experiment was carried out in a randomized complete block design (RCBD) in three replications over two crop years, 2018-2019, to compare the effects of genotype × trait (GT) and the genotype × yield-trait (GYT) methods as well as investigate the relationships between grain yield and different agronomic traits. Plant materials ten sunflowers (Helianthus annuus L.) genotypes. Based on the combined analysis of variance, there was a significant difference in parameters except leaf length. The effect of year × genotype was significant in all traits except plant height, stem diameter, and leaf length (P≤ 0.01). Gabur, Azargol and Favorite genotypes were ranked as genotypes in the years of the experiment. Based on the graphical analysis performed on the effect of genotype × trait (GT), Zaria genotype was selected as the best and stable genotype. The genotype × yield-trait (GYT) biplot ranked genotypes by yield and other desired trait levels and depicts their trait profiles, or strengths and weaknesses. The correlation biplot revealed positive correlations between most traits with grain yield. This method is pictorial, objective, effective, and simple compared to the genotype × trait (GT) method. The GYT biplot technique is based on the paradigm shift that genotypes should be assessed by their yield levels in combination with other variables rather than individually. The graphical analysis of the effect of genotype × yield-trait (GYT) revealed that Gabur and Armavirski genotypes were selected as the best for all traits investigated and could be recommended for cultivation in the Karaj location.

Keywords: sunflower; GT; GYT; graphic analysis; year × genotype; multi-traits