Identification of agromorphological and grain quality characteristics and evaluation in breeding studies of durum wheat landraces originating from Türkiye

This study was conducted in Antalya and Konya during 2021-2022 and 2023-2024 growing seasons, respectively. The aim of this study was to (a) compare the performance of durum wheat (Triticum durum Desf.) lines, developed through the selection breeding method from landraces, which were grown in periods when chemical inputs were not used for thousands of years across all regions of our country, with standard varieties that are widely cultivated in Turkey, for agronomical, quality and nutritional content, and (b) to identify new candidate varieties or breeding materials that can be used in breeding programs. In this context, in 2021-2022, a trial was conducted in Antalya according to an Augmented experimental design, along with 4 standard varieties (cvs. Burgos, Ovidio, Svevo, and Tirex) to select lines obtained by multiplying the seeds collected from individual spike rows. In this trial, traits such as spike color, spike length, days to heading, plant height, lodging, plant maturity, thousand kernel weight, SDS sedimentation value, durum wheat semolina color (b), wet gluten ratio, and gluten index were examined. Based on the data obtained, it was determined that the durum wheat genotypes showed a wide variation in all characteristics. To illustrate the range of variation: according to the variance analysis performed on the augmented experimental design, the adjusted means showed a variation of at least 20 days between early and late heading lines, with plant height ranging from 60 cm to 140 cm, thousand grain weight ranging from 37 g to 69 g, SDS sedimentation ranging from 9.5 mL to 26 mL, semolina color ranging from 17 to 26, and wet gluten ratio varying from 16% to %. Specifically, nine lines were prominent in terms of non-lodging and other agricultural and quality characteristics were selected for testing in the next trial. To test the winter adaptation of these selected lines, an experiment was conducted in Ilgın/Konya conditions during the 2023-2024 growing season using 7 standard varieties (Ç1252, Eminbey, Enduro, Karam, Kızıltan91, Leonardo, and Ovidio), in randomized complete blocks with three replications. In addition to the agricultural and quality traits examined in the first trial, macro/micro minerals and vitamin B compounds were also studied to determine the nutritional content of these lines. The data obtained showed a wide variation in each trait, and the selected lines, on average, had higher values than the standard varieties for days to heading, plant height, thousand grain weight, sedimentation volume, and wet gluten ratio, while they had lower values for grain yield, volume weight, semolina color, protein content, and gluten index, with statistical significance (p<0.01). On the other hand, in terms of micro/macronutrients, the potassium, magnesium, manganese, sodium, and selenium contents of the lines were statistically higher than the varieties. Regarding B vitamins, the lines were statistically higher (p<0.01) in terms of B2 vitamin, but no significant differences were found between the lines and the varieties for other B vitamins, including B1, B3, B5, B6, and B9. To further analyse the relationships between traits and genotypes, correlation, principal component, and two-way clustering analyses were performed. The results of the principal component analysis showed that, in the biplot graph, the standard varieties and Line 1 formed one group, while the other lines formed another group. In the two-way clustering analysis, all the genotypes were grouped into two main clusters, and all the standard varieties used in the experiment, except for the cv. Eminbey, were grouped into two sub-clusters. Based on the data obtained, it was concluded that the 9 tested lines showed a wide variation in almost all characteristics and could be used directly or as breeding-materials in durum wheat breeding programs. Specifically, Line 1, selected from the landrace with the IC 43106 accession number, was prominent than other lines due to its high grain yield, short plant height, and other average/high traits, and has the potential to be used directly as a candidate variety. However, to obtain more reliable results, further trials in different years and environments are necessary.