Summary Adaptive radiation in Ophrys orchids leads to complex floral phenotypes that vary in scent, color and shape. Using a novel pipeline to quantify these phenotypes, we investigated trait divergence at early stages of speciation in six populations of Ophrys aveyronensis experiencing recent allopatry. By integrating different genetic/genomic techniques, we investigated: variation and integration of floral components (scent, color and shape); phenotypes and genomic regions under divergent selection; and the genomic bases of trait variation. We identified a large genomic island of divergence, likely associated with phenotypic variation in particular in floral odor. We detected potential divergent selection on macular color, while stabilizing selection was suspected on floral morphology and for several volatile olfactive compounds. We also identified candidate genes involved in anthocyanin and in steroid biosynthesis pathways associated with standing genetic variation in color and odor. This study sheds light on early differentiation in Ophrys, revealing patterns that often become invisible over time, that is the geographic mosaic of traits under selection and the early appearance of strong genomic divergence. It also supports a crucial genomic region for future investigation and highlights the value of a multifaceted approach in unraveling speciation within taxa with large genomes.

中文翻译：

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Ophrys 兰花的花表型分化和基因组见解：揭示早期物种形成过程


摘要 Ophrys 兰花的适应性辐射导致复杂的花表型，这些表型在气味、颜色和形状上各不相同。使用一种新的管道来量化这些表型，我们调查了最近经历异体的 6 个 Ophrys aveyronensis 种群在物种形成早期阶段的性状差异。通过整合不同的遗传/基因组技术，我们研究了：花成分（气味、颜色和形状）的变化和整合;不同选择下的表型和基因组区域;以及性状变异的基因组基础。我们确定了一个大的基因组分化岛，可能与表型变异有关，特别是花香。我们在黄斑颜色上检测到潜在的发散选择，而在花形态和几种挥发性嗅觉化合物上怀疑稳定选择。我们还鉴定了参与花青素和类固醇生物合成途径的候选基因，这些途径与颜色和气味的站立遗传变异相关。这项研究揭示了 Ophrys 的早期分化，揭示了随着时间的推移通常变得不可见的模式，即选择下性状的地理马赛克和强烈基因组分化的早期出现。它还支持未来研究的关键基因组区域，并强调了多方面方法在揭示具有大型基因组的分类群内物种形成方面的价值。