Effect of allelic variations at the Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on flour characteristics and bread loaf volume

Authors: AHN, J - Chonbuk National University; KANG, C - National Institute Of Crop Science - Korea; JEUNG, J - National Institute Of Crop Science - Korea; Baik, Byung-Kee; PENA, R - International Maize & Wheat Improvement Center (CIMMYT); PARK, C - Chonbuk National University

Submitted to: International Food Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2014
Publication Date: 6/1/2014
Publication URL: http://handle.nal.usda.gov/10113/61384
Citation: Ahn, J.H., Kang, C.S., Jeung, J.U., Baik, B.-K., Pena, R.J., Park, C.S. 2014. Effect of allelic variations at the Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on flour characteristics and bread loaf volume. International Food Research Journal. 21(3):1177-1185.

Interpretive Summary: The bread-baking performance of wheat flour is largely determined by protein content and composition. Protein content is mainly controlled by environmental growing conditions, while protein composition is by genetic makeup; thus efforts for improving the bread-baking quality of wheat varieties have focused primarily on protein composition by the identification and implantation of genes responsible for encoding glutenin molecules desirable for baking bread. Kernel hardness of wheat influences milling yield, particle size and damaged starch content of flour, and subsequently affects bread baking quality. Variation in kernel hardness is known to be largely governed by the composition of two genes located in the hardness loci on chromosome 5D. Doubled haploid lines developed from the cross between an elite hard wheat variety and a soft wheat variety were used to determine how genetic variation at both the glutenin and kernel hardness loci are related to milling and biochemical characteristics of wheat flour, and how it affects the bread baking quality of wheat. Variation in one of the kernel hardness genes was responsible for 78.8 to 86.6% of variations in flour yield, particle size and damaged starch, with the two glutenin genes having comparatively smaller influences. Protein strength as measured by the SDS sedimentation volume test was affected by gene composition at the low molecular weight glutenin and kernel hardness loci. Variation of genes at the high molecular weight glutenin locus contributed to 51.0 and 10.8% of variations in mixing time and mixing tolerance of dough, respectively, with accompanying influences by the low molecular weight glutenin gene and one of the kernel hardness genes to lesser degrees. The kernel hardness genes also influenced the water absorption of dough. Composition of genes at the high molecular weight glutenin, low molecular weight glutenin and kernel hardness loci were responsible for 17.9, 4.9 and 8.4% of variation in bread loaf volume, respectively. It was found that the compositions of both the kernel hardness and glutenin genes have strong relationships with the bread baking quality of wheat flour by directly affecting flour particle size, damaged starch, and dough absorption for the former, and protein strength and dough mixing properties for the latter. This information will further boost our understanding of the contributions that glutenin and kernel hardness genes have on flour particle size, damaged starch and protein strength, and subsequently on the dough mixing properties of flour and loaf volume of bread, and eventually be helpful for development of the ideal composition of glutenin and kernel hardness genes for baking bread.

Technical Abstract: Doubled haploid wheat lines developed from a cross between Keumkang, a hard white winter wheat, and Olgeuru, soft red winter wheat were used to determine the effects of allelic variation in Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on physiochemical properties of flour and bread loaf volume. Variations in flour yield, average of particle size and damaged starch content were heavily affected by allelic composition on Pinb-D1 loci and its contribution was estimated to be 78.8, 83.5 and 86.6%, respectively. Glu-D1 and Glu-A3 alleles were also responsible for variation in those properties, but no significant influence of Glu-B3 alleles was observed. Variation in SDS-sedimentation volume was significantly affected by the allelic composition on Glu-A3 and Pinb-D1 loci, but allelic variations in glutenin and puroindoline exhibited little influence on protein content in DH lines. Glu-D1 allele showed biggest influence on mixing time and mixing tolerance of dough and its contributed 51.0 and 10.8% variations, respectively. Glu-B3 and Pinb-D1 alleles also affected mixing time and mixing tolerance of dough and Pinb-D1 allele variation influenced on water absorption of dough. Glu-D1, Glu-B3 and Pinb-D1 alleles were responsible for 17.9, 4.9 and 8.4% variation in bread loaf volume, respectively.