Pleistocene climate changes, and not agricultural spread, accounts for range expansion and admixture in the dominant grassland species Lolium perenne L.
Pleistocene climate changes, and not agricultural spread, accounts for range expansion and admixture in the dominant grassland species Lolium perenne L.
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DOI：
10.1111/jbi.13587
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发表时间：
2019-07-01
影响因子：
3.9
通讯作者：
Sampoux, Jean-Paul
中科院分区：
文献类型：
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作者：
Luis Blanco-Pastor, Jose;Manel, Stephanie;Sampoux, Jean-Paul
自新石器时代以来，草原一直是草食动物繁殖发展的关键，至今仍是欧洲最广泛的农业用地。然而，目前还不清楚欧洲天然草原上发现的植物物种的大规模遗传变异是人类活动还是自然过程的结果。位置欧洲。多年生黑麦草属（多年生黑麦草）。方法重建L.多年生草本植物是草地的优势种，利用481个自然居群，包括11个近缘类群的居群。我们将测序基因分型（GBS）和池测序（pool-Seq）相结合，以获得500 k SNP位点的高质量等位基因频率调用。我们进行了遗传结构分析和人口重建的基础上网站频谱（SFS）。我们还使用相同的基因分型协议，以评估一组的32个品种的代表L。多年生植物栽培品种广泛用于饲料目的。整个欧洲的扩张发生在乌尔姆冰期（12-110千年），一个冷却期，有利于草减少树木的优势。L.的分裂和混合物。多年生适合地中海盆地的历史气候变化。欧洲农业的发展（7-3.5千年），导致了草原丰富度的增加，但对L.多年生植物我们发现，大多数现代品种是密切相关的自然多样性从西北欧。因此，现代栽培品种并不代表在自然种群中发现的广泛遗传变异。主要结论L.多年生植物可以用更新世气候条件的变化来解释。自然种群在大陆尺度上保持着广泛的基因组变异性，最近的育种活动很少利用这种变异性。这种变异性构成了宝贵的长期遗传变异，使草原今后能够适应气候变化，保障它们提供的农业服务。
Aim Grasslands have been pivotal in the development of herbivore breeding since the Neolithic and still represent the most widespread agricultural land use across Europe. However, it remains unclear whether the current large-scale genetic variation of plant species found in natural grasslands of Europe is the result of human activities or natural processes. Location Europe. Taxon Lolium perenne L. (perennial ryegrass). Methods We reconstructed the phylogeographic history of L. perenne, a dominant grassland species, using 481 natural populations, including 11 populations of closely related taxa. We combined Genotyping-by-Sequencing (GBS) and pool-Sequencing (pool-Seq) to obtain high-quality allele frequency calls of 500 k SNP loci. We performed genetic structure analyses and demographic reconstructions based on the site frequency spectrum (SFS). We additionally used the same genotyping protocol to assess the genomic diversity of a set of 32 cultivars representative of the L. perenne cultivars widely used for forage purposes. Results Expansion across Europe took place during the Wurm glaciation (12-110 kya), a cooling period that decreased the dominance of trees in favour of grasses. Splits and admixtures in L. perenne fit historical climate changes in the Mediterranean basin. The development of agriculture in Europe (7-3.5 kya), that caused an increase in the abundance of grasslands, did not have an effect on the demographic patterns of L. perenne. We found that most modern cultivars are closely related to natural diversity from north-western Europe. Thus, modern cultivars do not represent the wide genetic variation found in natural populations. Main conclusions Demographic events in L. perenne can be explained by the changing climatic conditions during the Pleistocene. Natural populations maintain a wide genomic variability at continental scale that has been minimally exploited by recent breeding activities. This variability constitutes valuable standing genetic variation for future adaptation of grasslands to climate change, safeguarding the agricultural services they provide.