THE EFFECTS OF ALLELIC VARIATION FOR GLUTENIN HMW-GS ON DOUGH QUALITY IN SOME BREAD WHEAT CULTIVARS

The end-use quality of bread wheat is sensitive to cultivar (genotype) and the dominated extreme environmental conditions during the grain filling, as they effect on syntheses and accumulation of storage proteins (giiadin and glutenin) in grain. A field trials were carried out for three bread wheat cultivars (bohoth6, cham4 and cham6) at the four different environment zones in Syria for two seasons 2007 and 2008 to study the effects of the allelic variation in each studied cultivar (genotype) and effect of the dominant environmental conditions at each zone on gluten content and dough quality. Glutenin protein were analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis SDS-PAGE that demonstrated presence some allelic variations and the absence (deletion) of some alleles at loci on the chromosomes. Three different allelic were identified at (Glu-A1 and Glu-61) loci. The gluten content was the best in bohoth6, because there were no any allelic deletion at loci in comparison cham4 and cham6. So, the gluten content reduced when air temperature was raised above 30 °C for long duration coincident with water deficit during the grains filling period. The gluten quality was analyzed by Farinograph test (development time, stability and mixing tolerance), this test confirmed that bdhoth6 has the best allelic group for syntheses and accumulation of glutenin in grains. bohoth6 at zone2 and zone4 gave a dough strength ranging from the strongest in season 2007 to the medium grade in season 2008 as a result of effect the unusual extreme climatic conditions. The results indicated that bohoth6 was more tolerant to these extreme environmental conditions than cham4 and cham6.