Department of Plant Pathology, Kansas State University, Manhattan, KS, USA.
Global Wheat Program, International Maize and Wheat Improvement Center (CIMMYT), Mexico, DF, Mexico.
Commun Biol. 2021 Nov 1;4(1):1242. doi: 10.1038/s42003-021-02563-7.
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.
小麦产品的多样性主要源于六倍体面包小麦的起源，它将节节麦的 D 基因组添加到四倍体小麦中，从而使发酵面包具有更好的面团特性。然而，多倍化造成了遗传瓶颈，小麦 D 亚基因组中仅引入了有限的多样性。为了了解品质的遗传变异，我们对跨越已知节节麦多样性的 273 个品系进行了测序。我们在 Glu-D1 中发现了 45 个单倍型，Glu-D1 是品质的主要决定因素，相对于小麦中两个主要的单倍型。小麦等位基因 2 + 12 存在于小麦 D 亚基因组的供体节节麦 2 谱系中。相反，优质小麦等位基因 5 + 10 则起源于最近被描述的节节麦 3 谱系，这表明该重要等位基因具有独特的起源。这两个小麦等位基因在 Glu-D1 中与观察到的节节麦总分子多样性相比也非常相似。因此，节节麦是独特的 Glu-D1 等位基因的库，为小麦育种计划中利用新等位基因提高最终用途品质提供了基因组资源。
