Interaction between allelic variation at the Glu-D1 locus and a 1BL.1RS translocation on flour quality in bread wheat

1BL.1RS wheat (Triticum aestivum L.)-rye (Secale cereale L.) translocation has been widely used in wheat breeding programs all over the world. Serious defects in bread quality have been associated with the presence of the tra nslocation. The aim of this study was to evaluate the cumulative and intera ction effects on strength and mixing properties of dough ascribed to the al lelic variation for the Glu-D1 locus and to the presence of 1BL.1RS translo cation. A group of F-4-F-5 recombinant lines were developed from the cross between the 1BL.1RS inbred line S-55-87A and 'Gazul', a cultivar without th e translocation. Lines were cultivated for 2 yr and evaluated by the SDS-se dimentation test, mixograph, and alveograph. A highly significant differenc e between years was found in grain protein concentration, while 1BL.1RS tra nslocation or Glu-D1 alleles did not influence this parameter. The differen ce in sodium dodecylsulfate sedimentation (SDSS) volume mean value between lines with high molecular weight (HMW) 5+10 glutenin subunits and lines wit h HMW 2+12, considering only the set without the 1BL.1RS translocation, was four times lower than this difference in the set with the translocation, r eflecting a significant interaction between the effects of Glu-D1 alleles a nd 1B chromosome type. The detrimental effect on mixing properties caused b y 1BL.1RS rye translocation was dependent on the genetic background. No sig nificant differences among means were detected on mixing time and tolerance rate for presence or not of 1BL.1RS chromosomes. The presence of HMW 2+12 glutenin subunits and 1BL.1RS translocation produces a drastic decline in g luten strength, making it difficult to rind acceptable quality among genoty pes possessing both negative factors.