Protein composition for pairs of wheat lines with contrasting dough extensibility

Factors determining dough extensibility have been studied using two pairs of advanced breeding lines grown at five different locations in which individual 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 RAC746) did not show a significant difference in this parameter, making them suitable for the study of other factor(s) that influence extensibility, presumably genotypic in nature. The percentage of unextractable polymeric protein (UPP) differed appreciably between these two lines at all sires. This suggests that an important genotypic factor associated with extensibility is the molecular weight distribution of the protein. (C) 1999 Academic Press.