RELATIONSHIP BETWEEN GLIADIN ALLELES AND DOUGH STRENGTH IN ITALIAN BREAD WHEAT CULTIVARS

Dough strength, as determined by Alveograph W, was studied in Italian bread wheat cultivars grown at several locations over 21 years of test ing. Broad sense heritability of Alveograph W was found to range betwe en 0.40 and 0.82, variation in this parameter being affected by genoty pe x year interactions. Standardised Alveograph W values (Wst) across 40 environments (location-year combinations) were computed for 54 cult ivars with reference to the long-term control (cv. Mec), and a quality score based on the Wst value was given to each gliadin allele occurri ng in at least four of the 54 cultivars analysed. Significant differen ces in Wst values were observed at the Gli-B1, Gli-B2 and Gli-A2 loci. Alleles Gli-B1b, Gli-B2c and Gli-A2b were significantly related to hi gh gluten strength. An overall quality score based on allelic composit ion at these loci explained 41% of the observed Wst variation in the 5 4 cultivars used for the score definition, and 23% to 48% of W value v ariation in three sets of independent data. The combination of this sc ore with a quality score based on Glu-l alleles coding for high M-r gl utenin subunits could explain, on average, about 50% of gluten strengt h variation. (C) 1997 Academic Press Limited.