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Introduction Durum wheat (Triticum turgidum L. var. durum) is an important crop for the human diet grown in many parts of the world predominantly for semolina and resulting pasta production. The presence of genotype × environment interaction (GEI) is a challenge for breeders in evaluating genotypes in multilocational trials. The use of statistical models such as GGE biplot assist breeders in quantifying and understanding the patterns of GEI and in evaluating the performance of genotypes in various environmental conditions. This allows breeders to select stable and adaptable genotypes for a range of environments. One of the important goals of durum wheat breeding programs is to produce high-yielding cultivars that have suitable characteristics for cultivation in different regions of the country. Therefore, the aim of this research was to select promising durum wheat lines in terms of stability and high grain yield by GGE biplot and SHMM Materials and Methods In this study, 17 promising lines of durum wheat with three check Hana, Aran, Mehregan in five research centers of Kermanshah, Khorramabad, Karaj, Dezful and Fars (Darab) in the form of randomized complete blocks design in 3 replications and in two cropping seasons (2020-2022) were cultivated and compared. The studied genotypes were planted in six lines along 6 m with a line distance of 15 cm. Seed rate was determined by 450 seeds per square meter considering the thousand kernel weight for each genotype. Seeds were sown using an experimental plot planter (Wintersteiger, Ried, Austria). The fertilizer composition was 32 kg ha-1 nitrogen (twice), and diammonium phosphate and potassium sulfate were 100 and 50 kg ha-1, respectively (before planting). After the removal of perimeter plants, all experimental plots were harvested with an experimental grain harvester (Wintersteiger, Ried, Austria). Results and Discussion The results of the combined variance analysis of grain yield showed that the differences between the test environments, genotypes and genotype x environment interaction effect are significant at the 1% level. The highest grain yield in the first year was observed in Kermanshah station (Ker1) (8441 kg ha-1) and the lowest seed yield in Khorramabad in the first year (Kho1) (5648 kg ha-1) and Karaj in the second year (Kar2) (5961 kg ha-1). GGE biplot analysis determined two durum wheat environmental groups. The first environmental group contained of Kho1, Dar1, Kar1, Kar2 and Dar2 environments, where the recommended genotypes 18, 17, 2 and 19 produced the highest yields. The second environmental group comprised of Kho2, Dez1, Ker2, Dez2 and Ker1 environments, where genotypes 12, 9 and 8 were the best adapted genotypes. Biplot results showed that genotypes 10, 5, 13, 18 and 16 were more stable than other genotypes, respectively. Comparison of the examined genotypes with the ideal genotype showed that genotypes 18 and 10 are the closest genotypes to the ideal genotype, which in addition to high grain yield, had high yield stability. Dar2 was the closest environment to the ideal environment. The results showed that the classification of environments based on the SHMM model was completely consistent with the GGE biplot model. Based on environmental vector of the biplot, Dar2 and Ker1 had high discriminating ability for the genotypes. Also, Dezful in the first and second year (Dez1 and Dez2), Karaj in the second year (Kar2) and Kermanshah in the second year (Ker2) showed low discriminating ability for genotypes. The environments that were placed in the same group were close to each other in terms of genotype x environment interaction values. Based on the SHMM model, the environments with the least cross over effects are placed in one group. Accordingly, the placement of Kermanshah and Dezful in the same group indicates the relative similarity of these places. Also, these results were confirmed by the GGE biplot model. Conclusion As a conclusion, GGE biplot identified G10 (DW-99-10) and G18 (DW-99-18) as the superior durum wheat genotypes which that can be released as new commercial cultivars for the temperate and warm regions of Iran. [ABSTRACT FROM AUTHOR]

Background and objectives: Durum wheat (Triticum turgidum L. var. durum) is an industrial and agricultural product that is mainly used in pasta production industries. One of the important goals of durum wheat breeding programs is to produce high-yielding cultivars that have suitable characteristics for cultivation in different regions of the country. Therefore, the purpose of this research was to investigate the genotype × environment interaction using GGE biplot graphic method in durum wheat promising lines and to identify and introduce lines with economic and stable yield for introduction and cultivation in different regions of the country. Materials and methods: In this experiment, 18 promising lines of durum wheat with two check Hana and Aran in five research stations of Karaj, Kermanshah, Khorramabad, Dezful and Darab (under two conditions of normal irrigation and irrigation cutting during the flowering stage) were cultivated and compared in the form of randomized complete blocks design in three replications and in two cropping seasons (2019-2021). Results: The results of two-year combined variance analysis for grain yield under normal irrigation conditions in five research stations of Darab, Dezful, Khorramabad, Karaj and Kermanshah and dry conditions at the end of the season in Darab showed that the effect of year in both conditions and all stations was significant. In normal irrigation conditions, the difference between genotypes grain yield was significant in Darab, Dezful and Kermanshah stations, but not significant in Karaj and Khorramabad stations. Genotype × year interaction was significant under normal conditions in Darab and Kermanshah, but not significant in Karaj, Dezful and Khorramabad. Based on the average grain yield, lines G8, G9, G10, G14 and G18 (respectively with the average grain yield of 7725, 7597, 7742, 7661 and 7558 Kg ha-1) were superior to the controls. According to the GGE biplot, three large environments were identified. The first large environment included Dezful and Khorramabad regions, and G8 and G10 genotypes were among the top genotypes in these two regions, respectively. The second largest environment was Kermanshah and Karaj, and G9 and G14 genotypes were among the top genotypes in these two regions. The third large environment included two test conditions in Darab and the superior genotype in Darab was G18 in both drought stress and non-stress conditions. GGE Biplot results showed that G8 and G10 genotypes were among the most stable lines and also had the highest grain yield. The comparison of the studied lines with the ideal genotype showed that G10 and G8 are the closest genotypes to the ideal genotype, which have the highest grain yield and stability. The results of qualitative characteristics showed that the hardness index average of genotypes was in the range of 57-58% and the promising lines were not significantly different from the control cultivars. G17 genotype had the lowest (14%) and G14 genotype had the highest average of grain yellow berry (45%). Also, a relatively large variation was observed in terms of the amount of wet gluten, so that genotypes G9 and G13 had the lowest and highest amount of wet gluten with 23.8 and 27.3%, respectively. Conclusion: In general, according to the average grain yield and GGE biplot results in both normal and drought conditions and according to some quality characteristics of the grain, lines G8 (D-98-8) and G10 (D-98-10) were selected as the most suitable lines for both normal and dry conditions. These lines will be tested in on-farm yield trials of next crop season and finally one of them will be introduced as a new cultivar. [ABSTRACT FROM AUTHOR]