Relationships between Gliadins and Bread-Making Quality Properties in Winter and Spring Wheats of Northwest Iran, Compared with Improved Cultivars



A total of 165 wheat landraces with their originated from Northwest regions of Iran were studied at Research Station of Agricultural Faculty, Univ. of Tabriz, using two experimental designs in two spring and fall growing seasons. During these experiments, growth habits of 104 wheat landraces were assessed and their representative seeds harvested in similar conditions. These landraces were analysed through A-PAGE for gliadin proteins, and as well were analysed for the proteins of 44 improved wheat cultivars grown in Iran. Some small scale bread-making quality properties including protein content, Zeleny sedimentation, water absorption rate, bread loaf volume, SDS-sedimentation and Grain hardness were tested. All gliadin bands were polymorphic (in either one of the landraces or cultivars). Average number of gliadin bands were 28±1.34 for winter landraces, showing a significant difference as compared to winter cultivars (21±0.89). However, average number of gliadins in spring wheats were not significantly different (25±1.21 for landraces and 26±1.33 for cultivars). Means of quality indices were higher in improved cultivars as compared with those in landraces, but only grain hardners and water absorption rates showed significant differences (p<5%). These means were also high in spring wheats specially regarding protein content, Zeleny sedimentation and loaf volume. Statistical analyses revealed significantly positive correlations between own quality properties and between each of them and 7 to 11 gliadin bands and also significantly negative correlations with other gliadins. Further analyses based on informative bands for each quality property indicated the possible use of Gene Bank of SPII winter landraces of 10425, 11071, 11203 and 12074 and spring landraces 10422, 11012, 11204 and 11422 in breeding programs for quality improvement of wheat cultivars.