Protein composition for pairs of wheat lines with contrasting dough extensibility

Factors determining dough extensibility have been studied using two pairs o f advanced breeding lines grown at five different locations in which indivi dual lines of each pair differed in extensibility. For one pair (DD118 and RAC704), the differences related mainly to variations in the percentage of flour polymeric protein. On the other hand, the second pair (VF304 and RAC7 46) did not show a significant difference in this parameter, making them su itable for the study of other factor(s) that influence extensibility, presu mably genotypic in nature. The percentage of unextractable polymeric protei n (UPP) differed appreciably between these two lines at all sires. This sug gests that an important genotypic factor associated with extensibility is t he molecular weight distribution of the protein. (C) 1999 Academic Press.