EFFECT OF GLIADINS AND HMW AND LMW SUBUNITS OF GLUTENIN ON DOUGH PROPERTIES IN THE F-6 RECOMBINANT INBRED LINES FROM A BREAD WHEAT CROSS

The storage proteins of 64 F-2-derived F-6 recombinant inbred lines (R ILs) from the bread wheat cross 'Prinqual'/'Marengo' were analyzed. Pa rents differed at four loci: Gli-B1 (coding for gliadins), Glu-B1 (cod ing for HMW glutenin subunits), Glu-A3/Gli-A1 (coding for LMW glutenin subunits/gliadins) and Glu-D3 (coding for LMW glutenin subunits). The effect of allelic variation at these loci on tenacity, extensibility and dough strength as measured by the Chopin alveograph was determined . Allelic differences at the Glu-B1 locus had a significant effect on only tenacity. None of the allelic differences at either the Glu-A3/Gl i-A1 or Glu-D3 loci had a significant effect on quality criteria. Alle lic variation at the Gli-B1 locus significantly affected all of the do ugh properties. Epistatic effects between some of the loci considered contributed significantly to the variation in dough quality. Additive and epistatic effects each accounted for 15% of the variation in tenac ity. Epistasis accounted for 15% of the variation in extensibility, wh ereas additive effects accounted for 4%. Epistasis accounted for 14% o f the variation in dough strength, and additivity for 9%. The relative importance of epistatic effects suggest that they should be included in predictive models when breeding for breadmaking quality.