University of Guilan Cereal Research 2252-0163 10 1 2020 05 21 Assessment of relationships among traits and selection of superior bread wheat genotypes using genotype by yield × trait biplot method Assessment of relationships among traits and selection of superior bread wheat genotypes using genotype by yield × trait biplot method 61 72 4387 10.22124/cr.2020.15458.1551 FA Mahnaz Rahmati Research Assist. Prof., Dept. of Seed and Plant Improvement Research, Lorestan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Khorramabad, Iran Journal Article 2019 12 15 Selection of high yielding and stable genotypes is especially important for rainfed conditions. The objective of this study was to use the genotype by yield × trait (GYT) biplot method to select superior bread wheat genotypes based on yield-trait combinations under rain-fed conditions. To this end, 16 bread wheat genotypes were assessed in a randomized complete block design with four replications in two cropping seasons, 2017-2019. Comparison of average grain yield of genotypes in the experimental years showed that genotypes G1 (Aftab), G15 and G8 had the highest grain yield with an average yield 3433, 3269 and 3233 kg/ha, respectively. The result of polygon view of GYT biplot showed that G8 was the best genotype in combining grain yield with 1000-kernel weight, number of grain per spike and spike length. Similarity, G1 also had a relative superiority in combining grain yield with number of spikelet per spike, awn length and early maturity. Average tester coordinate (ATC) view of GYT biplot indentified genotypes G8, G1 and G15 with all positive yield-trait combinations as the best genotypes and genotypes G14, G4, G13 and G7 as the weakest genotypes. Genotypes G15 and G16 were also balanced for yield- trait combinations. Ranking of the genotypes based on GYT index showed that genotypes G8, G1 and G15 had the best genotypes in combining grain yield with the evaluated traits in the experimental years. Based on the results of this study, high correlations were observed between 1000-kernel weight, number of grain per spike and grain weight per spike in combination with grain yield, indicating high efficiency of combining these traits with grain yield to improve productivity of bread wheat genotypes under rainfed conditions. Selection of high yielding and stable genotypes is especially important for rainfed conditions. The objective of this study was to use the genotype by yield × trait (GYT) biplot method to select superior bread wheat genotypes based on yield-trait combinations under rain-fed conditions. To this end, 16 bread wheat genotypes were assessed in a randomized complete block design with four replications in two cropping seasons, 2017-2019. Comparison of average grain yield of genotypes in the experimental years showed that genotypes G1 (Aftab), G15 and G8 had the highest grain yield with an average yield 3433, 3269 and 3233 kg/ha, respectively. The result of polygon view of GYT biplot showed that G8 was the best genotype in combining grain yield with 1000-kernel weight, number of grain per spike and spike length. Similarity, G1 also had a relative superiority in combining grain yield with number of spikelet per spike, awn length and early maturity. Average tester coordinate (ATC) view of GYT biplot indentified genotypes G8, G1 and G15 with all positive yield-trait combinations as the best genotypes and genotypes G14, G4, G13 and G7 as the weakest genotypes. Genotypes G15 and G16 were also balanced for yield- trait combinations. Ranking of the genotypes based on GYT index showed that genotypes G8, G1 and G15 had the best genotypes in combining grain yield with the evaluated traits in the experimental years. Based on the results of this study, high correlations were observed between 1000-kernel weight, number of grain per spike and grain weight per spike in combination with grain yield, indicating high efficiency of combining these traits with grain yield to improve productivity of bread wheat genotypes under rainfed conditions. https://cr.guilan.ac.ir/article_4387_2c7d0bae85f9b6967caf8021f014ec75.pdf