Addition of aegilops U and M chromosomes affects protein and dietary fiber content of wholemeal wheat flour

Abstract

Cereal grain fiber is an important health-promoting component in the human diet. One option to improve dietary fiber content and composition in wheat is to introduce genes from its wild relatives Aegilops biuncialis and Aegilops geniculata. This study showed that the addition of chromosomes 2Ug, 4Ug, 5Ug, 7Ug, 2Mg, 5Mg, and 7Mgof Ae. geniculata and 3Ub, 2Mb, 3Mb, and 7Mbof Ae. biuncialis into bread wheat increased the seed protein content. Chromosomes 1Ug and 1Mg increased the proportion of polymeric glutenin proteins, while the addition of chromosomes 1Uband 6Ubled to its decrease. Both Aegilops species had higher proportions of b-glucan compared to arabinoxylan (AX) than wheat lines, and elevated b-glucan content was also observed in wheat chromosome addition lines 5U, 7U, and 7M. The AX content in wheat was increased by the addition of chromosomes 5Ug, 7Ug, and 1Ubwhile water-soluble AX was increased by the addition of chromosomes 5U, 5M, and 7M, and to a lesser extent by chromosomes 3, 4, 6Ug, and 2Mb. Chromosomes 5Ugand 7Mbalso affected the structure of wheat AX, as shown by the pattern of oligosaccharides released by digestion with endoxylanase. These results will help to map genomic regions responsible for edible fiber content in Aegilops and will contribute to the efficient transfer of wild alleles in introgression breeding programs to obtain wheat varieties with improved health benefits. Key Message: Addition of Aegilops U- and M-genome chromosomes 5 and 7 improves seed protein and fiber content and composition in wheat.