Prieto Ivan, Litrico Isabelle, Violle Cyrille, Barre Philippe
CNRS, CEFE UMR 5175, Université de Montpellier-Université Paul Valéry-EPHE, 1919 Route de Mende 34293 Montpellier Cedex 5, France
INRA, URP3F, RD 150, site du chêne, BP 86006 86600 Lusignan, France.
Am J Bot. 2017 Jan;104(1):62-71. doi: 10.3732/ajb.1600354. Epub 2017 Jan 12.
Current ecological theory can provide insight into the causes and impacts of plant domestication. However, just how domestication has impacted intraspecific genetic variability (ITV) is unknown. We used 50 ecotypes and 35 cultivars from five grassland species to explore how selection drives functional trait coordination and genetic differentiation.
We quantified the extent of genetic diversity among different sets of functional traits and determined how much genetic diversity has been generated within populations of natural ecotypes and selected cultivars.
In general, the cultivars were larger (e.g., greater height, faster growth rates) and had larger and thinner leaves (greater SLA). We found large (average 63%) and trait-dependent (ranging from 14% for LNC to 95.8% for growth rate) genetic variability. The relative extent of genetic variability was greater for whole-plant than for organ-level traits. This pattern was consistent within ecotypes and within cultivars. However, ecotypes presented greater ITV variability.
The results indicated that genetic diversity is large in domesticated species with contrasting levels of heritability among functional traits and that selection for high yield has led to indirect selection of some associated leaf traits. These findings open the way to define which target traits should be the focus in selection programs, especially in the context of community-level selection.
当前的生态理论能够为植物驯化的原因及影响提供见解。然而，驯化究竟如何影响种内遗传变异性（ITV）尚不清楚。我们使用了来自五种草原物种的50个生态型和35个栽培品种，以探究选择如何驱动功能性状协调和遗传分化。
我们量化了不同功能性状组之间的遗传多样性程度，并确定了在自然生态型和选定栽培品种的种群中产生了多少遗传多样性。
总体而言，栽培品种植株更大（如更高、生长速率更快），叶片更大更薄（比叶面积更大）。我们发现了大量（平均63%）且依赖于性状的遗传变异性（从叶氮含量的14%到生长速率的95.8%不等）。全株水平的遗传变异性相对程度大于器官水平的性状。这种模式在生态型和栽培品种内部都是一致的。然而，生态型呈现出更大的种内遗传变异性。
结果表明，驯化物种的遗传多样性很大，功能性状的遗传力水平存在差异，并且对高产的选择导致了对一些相关叶片性状的间接选择。这些发现为确定在选择计划中应关注哪些目标性状开辟了道路，特别是在群落水平选择的背景下。
