Evaluation of bread wheat (Triticum aestivum L.) cultivars improved before and after millennium for grain yield and quality by genotype by environment interactions using gge biplot method

The study was carried out with twenty-five bread wheat genotypes registered or licensed for production before and after 2000 in the Thrace Region in a total of nine environments, including three years and three locations to the randomized block trial design with 3 replications. With the research, grain yield and yield components such as plant height, spike length, number of spikelets per spike, number of grains per spike, grain weight per spike, harvest index, and quality parameters such as thousand grain weight, test weight, protein ratio, gluten ratio, gluten index, sedimentation value. It is aimed to make evaluations using the GGE biplot method. In addition, evaluations on parametric stability such as coefficient, stability variance and geometric adaptability index with the GGE Biplot method, regression coefficient, variance of deviations from the regression line, coefficient of, echovalence stability index, etc. as well as S_i^((1-4)) and 〖NP〗^((1-4) ) non-parametric stability analyzes were also included in the study. When compared to the registered or production licensed varieties before the millennium, it is noteworthy that the later ones have higher grain yield and lower plant height and thousand grain weight averages. Especially according to the combined environmental averages, the highest grain yield was obtained in Bora variety, followed by Rumeli, Sarı Mustafa, Selimiye, Tekirdağ varieties, respectively. It has been observed that these varieties have low stability and environmental selectivity. It has been understood that Bora and Rumeli varieties have high adaptation to good environmental conditions, while Selimiye and Tekirdağ varieties have high adaptation to bad environmental conditions. According to the protein ratio results, Enargo, Bezostaja-1, Rumeli, Murat-1, Sarajevo, Delebrad-2, Flamura-80, Esperia varieties showed the highest performance and among these eight varieties, Bezostaja-1, The stability of Delebrad-2 varieties was found to be high, while the stability of the other six varieties was found to be low.