Effect of 1R(1A), 1R(1B) and 1R(1D) substitution on technological value of bread wheat

Fifteen wheat (Triticum aestivum L.) substitution lines carrying 1R(1A) or 1R(1B) or 1R(1D) substitutions and derived from nine genetic backgrounds were used to evaluate the effect of the 1R (rye, Secale cereale L.) chromosome on wheat flour quality when substituted with group 1 chromosomes. The substituted lined were identified by the presence of M. secalin subunits encoded at Glu-R1 and by the absence of high and low M. glutenin subunits encoded respectively at the Glu-1 and Glu-3 loci. Direct and indirect technological tests were conducted and intervarietal, year of growth and substitution effects were studied. Alveogram and Mixogram parameters, protein concentration and grain hardness were measured for two years of growth. In addition Zeleny, viscosity of water extractable arabinoxylans (WeAx) and baking tests were carried out on material grown in the second year. Significant differences between years were detected for protein concentration, three parameters of Mixogram (midline peak width MPW, midline right width (MRW and weakening slope WS) and two of Alveogram (strength W and swelling G). Intervarietal and substitution effects were shown in the majority of parameters. The contribution of the three substitutions on breadmaking quality demonstrated that substitution 1R(1A) had a significant positive effect compared to 1R(1B) and 1R(1D) substitutions. The allele encoding high M. secalin subunit (6.5) at Glu-R1 had an intermediate value between Glu-A1c (null allele) and subunit 2* encoded at Glu-A1. At Glu-B1, an equivalence was noted between the secalin subunit (6.5) and glutenin subunit 7. However, the secalin subunit (6.5) was always inferior to subunits at Glu-D1. In addition the genetic background was of dramatic importance in explaining the variations particularly for grain hardness, which declined, when normal lines were of hard type, in the 1R(1A) and the 1R(1D) substitutions. Contrary to what has been found until now in 1BL/1RS translocation genotypes, substitution decreased WeAx viscosity. Moreover, pentosans and Zeleny explained a great part of the loaf volume variations.