Moreno-Letelier Alejandra, Aguirre-Liguori Jonás A, Piñero Daniel, Vázquez-Lobo Alejandra, Eguiarte Luis E
Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México.
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México.
R Soc Open Sci. 2020 Apr 15;7(4):191545. doi: 10.1098/rsos.191545. eCollection 2020 Apr.
The widespread use of genomic tools has allowed for a deeper understanding of the genetics and the evolutionary dynamics of domestication. Recent studies have suggested that multiple domestications and introgression are more common than previously thought. However, the ability to correctly infer the many aspects of domestication process depends on having an adequate representation of wild relatives. Cultivated maize ( ssp. ) is one of the most important crops in the world, with a long and a relatively well-documented history of domestication. The current consensus points towards a single domestication event from teosinte ssp. from the Balsas Basin in Southwestern Mexico. However, the underlying diversity of teosintes from ssp and ssp. was not taken into account in early studies. We used 32 739 single nucleotide polymorphisms (SNPs) obtained from 29 teosinte populations and 43 maize landraces to explore the relationship between wild and cultivated members of We then inferred the levels of gene flow among teosinte populations and maize, the degree of population structure of subspecies, and the potential domestication location of maize. We confirmed a strong geographic structure within ssp. and documented multiple gene flow events with other members of the genus, including an event between ssp. and maize. Our results suggest that the likely ancestor of maize may have been domesticated in Jalisco or in the southern Pacific Coast and not in the Balsas Basin as previously thought. In this context, different populations of both teosinte subspecies have contributed to modern maize's gene pool. Our results point towards a long period of domestication marked by gene flow with wild relatives, confirming domestication as long and ongoing process.
基因组工具的广泛应用使人们对驯化的遗传学及进化动态有了更深入的了解。近期研究表明，多次驯化和基因渗入比之前认为的更为普遍。然而，正确推断驯化过程诸多方面的能力取决于是否有足够的野生近缘种代表。栽培玉米（亚种）是世界上最重要的作物之一，有着悠久且记录相对完善的驯化历史。目前的共识是，驯化事件源于墨西哥西南部巴尔萨斯盆地的大刍草亚种。然而，早期研究并未考虑大刍草亚种和亚种的潜在多样性。我们使用从29个大刍草种群和43个玉米地方品种中获得的32739个单核苷酸多态性（SNP）来探究野生和栽培成员之间的关系。然后，我们推断了大刍草种群与玉米之间的基因流动水平、亚种的种群结构程度以及玉米的潜在驯化地点。我们证实了亚种内部存在强烈的地理结构，并记录了与该属其他成员的多次基因流动事件，包括亚种与玉米之间的一次事件。我们的结果表明，玉米可能的祖先可能是在哈利斯科州或太平洋沿岸南部被驯化的，而不是如之前所认为的在巴尔萨斯盆地。在这种情况下，两个大刍草亚种的不同种群都对现代玉米的基因库做出了贡献。我们的结果表明，驯化过程漫长，其特征是与野生近缘种的基因流动，这证实了驯化是一个长期且持续的过程。
