High molecular weight glutenin gene diversity in Aegilops tauschii demonstrates unique origin of superior wheat quality
Emily Delorean, Liangliang Gao, Jose Fausto Cervantes Lopez, Ali Ashraf Mehrabi, Alison R. Bentley, Amir Sharon, Beat Keller, Brande B. H. Wulff, Brian J. Steffenson, Burkhard Steuernagel, Carolina Sansaloni, Dengcai Liu, Evans Lagudah, Firuza Nasyrova, Gina Brown‐Guedira, Hanan Sela, Jan Dvořák, Jesse Poland, Klaus Mayer, Ksenia V. Krasileva, Kumar Gaurav, Long Mao, Mario Cáccamo, Martin Mascher, Ming‐Cheng Luo, Parveen Chhuneja, Robert Davey, Justin D. Faris, Steven S. Xu, P. Nicholson, Noam Chayut, Mike Ambrose, Nidhi Rawat, Vijay Tiwari, Brande B. H. Wulff, María Itria Ibba, Jesse Poland
Abstract
Central to the diversity of wheat products was the origin of hexaploid bread wheat, which added the D-genome of Aegilops tauschii to tetraploid wheat giving rise to superior dough properties in leavened breads. The polyploidization, however, imposed a genetic bottleneck, with only limited diversity introduced in the wheat D-subgenome. To understand genetic variants for quality, we sequenced 273 accessions spanning the known diversity of Ae. tauschii. We discovered 45 haplotypes in Glu-D1, a major determinant of quality, relative to the two predominant haplotypes in wheat. The wheat allele 2 + 12 was found in Ae. tauschii Lineage 2, the donor of the wheat D-subgenome. Conversely, the superior quality wheat allele 5 + 10 allele originated in Lineage 3, a recently characterized lineage of Ae. tauschii, showing a unique origin of this important allele. These two wheat alleles were also quite similar relative to the total observed molecular diversity in Ae. tauschii at Glu-D1. Ae. tauschii is thus a reservoir for unique Glu-D1 alleles and provides the genomic resource to begin utilizing new alleles for end-use quality improvement in wheat breeding programs.