Tracing the ancestry of modern bread wheats

First author: Caroline Pont; Affiliations: Université Clermont Auvergne (克莱蒙奥弗涅大学): Clermont-Ferrand, France

Corresponding author: Jérôme Salse

For more than 10,000 years, the selection of plant and animal traits that are better tailored for human use has shaped the development of civilizations. During this period, bread wheat (Triticum aestivum) emerged as one of the world’s most important crops. We use exome sequencing of a worldwide panel of almost 500 genotypes selected from across the geographical range of the wheat species complex to explore how 10,000 years of hybridization, selection, adaptation and plant breeding has shaped the genetic makeup of modern bread wheats. We observe considerable genetic variation at the genic, chromosomal and subgenomic levels, and use this information to decipher the likely origins of modern day wheats, the consequences of range expansion and the allelic variants selected since its domestication. Our data support a reconciled model of wheat evolution and provide novel avenues for future breeding improvement.

在一万多年以来，对于动、植物性状的选择以便人类加以利用已经改变了人类历史文化的进程。在这期间，作为世界上最重要的作物之一的面包小麦（Triticum aestivum）出现了。 本文通过对世界范围不同地理区域的、约500个基因型的小麦进行了外显子组测序，研究10000年来小麦的杂交、选择、适应以及植物育种对于现代面包小麦遗传组成的影响。作者在基因、染色体以及亚基因组水平上均观察到了相当多的遗传变异，利用这些遗传变异信息，作者破译了现代小麦可能的起源，分布区扩张带来的影响以及驯化过程中受到选择的等位基因型。本文的研究结果支持小麦的演化符合reconciled模型，并且为将来小麦的育种改良提供了新的途径。

通讯：Jérôme Salse(https://www6.clermont.inra.fr/umr1095_eng/Staff/S/SALSE-Jerome)

个人简介：1999年，图卢兹三世大学，硕士；2002年，佩皮尼昂大学，博士。

研究方向：植物比较基因组学。

doi: https://doi.org/10.1038/s41588-019-0393-z

Journal: Nature Genetics

Published date: May 01, 2019

Exome sequencing highlights the role of wild-relative introgression in shaping the adaptive landscape of the wheat genome

First author: Fei He; Affiliations: Kansas State University (堪萨斯州立大学): Manhattan, USA

Corresponding author: Eduard Akhunov 

Introgression is a potential source of beneficial genetic diversity. The contribution of introgression to adaptive evolution and improvement of wheat as it was disseminated worldwide remains unknown. We used targeted re-sequencing of 890 diverse accessions of hexaploid and tetraploid wheat to identify wild-relative introgression. Introgression, and selection for improvement and environmental adaptation, each reduced deleterious allele burden. Introgression increased diversity genome wide and in regions harboring major agronomic genes, and contributed alleles explaining a substantial proportion of phenotypic variation. These results suggest that historic gene flow from wild relatives made a substantial contribution to the adaptive diversity of modern bread wheat.

基因渐滲（Introgression）是有益遗传多样性的潜在来源。而基因渐滲对于小麦的适应性演化和遗传改良，以及小麦在全球传播的作用还不清楚。作者通过对890份四倍体和六倍体小麦材料进行了靶向重测序，用以鉴定栽培种小麦种来自野生近缘种的基因滲入。用于改良和环境适应的基因滲入和选择能够降低有害等位基因负荷。基因滲入增加了基因组范围上的多样性，尤其是包含主要农艺基因的基因组区域，并且作用于能够解释绝大部分表型变异的等位基因。本文的研究结果说明历史上来自野生近缘种的基因流对于现代育种小麦的适应多样性有着很重要的作用。

Introgression, 指两个种之间杂交产生可育的杂种后代，并通过重复多代连续回交使得两个种的基因库之间实现基因流动。

通讯：Eduard Akhunov (https://www.plantpath.k-state.edu/people/faculty/akhunov/)

个人简介：1992年，新西伯利亚州立大学，学士；1999年，俄罗斯遗传学研究所，博士。

研究方向：抗病基因和植物与病原菌相互作用机制；小麦遗传改良的遗传、基因组工具及资源；小麦区域性适应的遗传基础；小麦基因组多样性与演化。

doi: https://doi.org/10.1038/s41588-019-0382-2

Journal: Nature Genetics

Published date: May 01, 2019