Stability properties of certain durum wheat genotypes for major quality characteristics

Many ecological regions of Turkey are suitable for the production of durum wheat, and therefore the yield and quality of this wheat should be improved. In this study, stability properties associated with the pasta quality of 25 durum wheat (Triticum durum Desf.) genotypes grown in 3 different locations (Tokat-Kazova, Diyarbakir, and Sivas-Ulas) for 2 years (2005-2006, 2006-2007) were investigated. Durum wheat genotypes were composed of 12 registered varieties and 13 advanced experimental lines. Field trials were conducted in a randomized complete block design with 3 replications. Protein content, gluten index, sedimentation and specific sedimentation volumes, yellow pigment content, and lipoxygenase activity of the durum wheats were measured as major quality characteristics. The regression coefficient (b(i)) and mean square of deviation from regression (S-d(2)) were employed as the stability parameters. Genotypes, growing environments, and their interactions were found to be statistically significant (P < 0.01) for all investigated quality characteristics. No cultivars were determined to be simultaneously stable for all of the quality characteristics, yet some of the genotypes prevailed for certain quality characteristics. The genotypes with the same origin took part in the same group as judged by the cluster analysis. Of the advanced experimental durum wheat lines, Line - 1, Line - 7, Line - 20, and Gdem - 12, which displayed better quality characteristics than the overall means, can be used as breeding materials. Of the registered varieties, Aydin - 93, Cesit - 1252, and Gidara were determined to be stable by both parameters in certain quality characteristics.