Durum wheat genome highlights past domestication signatures and future improvement targets

First author: Marco Maccaferri; Affiliations: University of Bologna (博洛尼亚大学): Bologna, Italy

Corresponding author: Luigi Cattivelli

The domestication of wild emmer wheat led to the selection of modern durum wheat, grown mainly for pasta production. We describe the 10.45  gigabase (Gb) assembly of the genome of durum wheat cultivar Svevo. The assembly enabled genome-wide genetic diversity analyses revealing the changes imposed by thousands of years of empirical selection and breeding. Regions exhibiting strong signatures of genetic divergence associated with domestication and breeding were widespread in the genome with several major diversity losses in the pericentromeric regions. A locus on chromosome 5B carries a gene encoding a metal transporter (TdHMA3-B1) with a non-functional variant causing high accumulation of cadmium in grain. The high-cadmium allele, widespread among durum cultivars but undetected in wild emmer accessions, increased in frequency from domesticated emmer to modern durum wheat. The rapid cloning of TdHMA3-B1 rescues a wild beneficial allele and demonstrates the practical use of the Svevo genome for wheat improvement.

野生二粒小麦的驯化形成了现代硬粒小麦，而后者目前在全球广泛种植用来生产面粉。本文报道了硬粒小麦栽培品种Svevo的10.45Gb的基因组。本文报道的基因组使得我们能够从基因组层面上研究小麦的遗传多样性，从而揭示数千年来人们的选择和育种对于小麦基因组所带来的影响。与驯化和育种相关的遗传多样性信号广泛分布于整个小麦基因组，但在着丝粒区域存在严重的多样性丢失现象。染色体5B上的一个位点包含一个金属转运蛋白编码基因TdHMA3-B1，该基因功能丢失会导致小麦籽粒中过量积累镉。高镉等位基因在所有的硬粒小麦栽培品种中广泛存在，但在野生二粒小麦中则比较稀有，说明该等位基因的频率在野生二粒小麦驯化成为现代硬粒小麦的过程中增加了。TdHMA3-B1的快速克隆帮助我们找回了一个野生种中的有益等位基因，说明了本文所报道的Svevo基因组有利于小麦育种的实践应用。

通讯：Luigi Cattivelli（https://person.zju.edu.cn/ywteng/0.html）

研究方向：大麦和小麦等谷物的遗传和分子生物学。

doi: https://doi.org/10.1038/s41588-019-0381-3

Journal: Nature Genetics

Published date: April 08, 2019