Heuertz Myriam, Escudero Marcial, Gómez José María, Vargas Pablo
Univ. Bordeaux, INRAE, BIOGECO, 69 route d'Arcachon, F-33610 Cestas, France.
Department of Plant Biology and Ecology, University of Seville, Reina Mercedes 6, E-41012 Seville, Spain.
AoB Plants. 2025 Mar 24;17(4):plaf017. doi: 10.1093/aobpla/plaf017. eCollection 2025 Aug.
The snapdragon has been a model species for genetics, plant development, and evolution since the 19th century. Recent studies have expanded the focus to the entire genus as a model system for rapid evolution (26 species in < 5 million years). However, in-depth studies to reconstruct microevolution in additional snapdragon species are lacking. This study aimed to explore to what extent potential pollinators, flower colour morphs, spatial and environmental factors contribute to differentiation in a small population of the Mediterranean (south-eastern Spain). We studied a population of approximately 200 individuals with either pink or white corollas, characterized by strong topographic heterogeneity (horizontal extension of 120 × 80 meters; 40-meter altitude difference) and diversity in environmental factors (substrate, vegetation). The study analysed pollinator preference for either white or pink corollas, genetic diversity using 13 nuclear SSR loci and three plastid haplotypes, and the spatial population structure. Flower visitors displayed some indication of preference for pink corollas (five of ten bee species) and flower colour morphs were genetically differentiated. However, the strongest pattern of genetic differentiation was associated with a fine-scale spatio-topographic isolation in the population, with five topo-genetic subpopulations and a pollen-to-seed dispersal distance ratio of 4.32. Our results agree with similar patterns of strong spatial genetic isolation found in at larger scales: phylogeographic differentiation of populations and phylogenetic relationships within a south-eastern Iberian clade. Despite the extreme corolla specialization for bee pollination, spatial isolation appears to be the predominant factor driving short- and long-term differentiation in . We argue that a comprehensive understanding of early stages of rapid evolution requires detailed investigation of fine-scale evolutionary drivers, including both spatial isolation (topography) and ecological factors (e.g. pollination fauna).
自19世纪以来，金鱼草一直是遗传学、植物发育和进化领域的模式物种。最近的研究将重点扩展到整个属，将其作为快速进化的模式系统（在不到500万年的时间里有26个物种）。然而，缺乏对其他金鱼草物种微观进化进行重建的深入研究。本研究旨在探讨潜在传粉者、花色形态、空间和环境因素在多大程度上导致了地中海地区（西班牙东南部）一个小种群的分化。我们研究了一个约有200个个体的种群，其花冠要么为粉色，要么为白色，其特点是地形高度异质性（水平延伸120×80米；海拔差40米）以及环境因素（基质、植被）的多样性。该研究分析了传粉者对白色或粉色花冠的偏好、使用13个核SSR位点和三种质体单倍型的遗传多样性以及种群的空间结构。访花者表现出对粉色花冠有一定的偏好迹象（十分之五的蜜蜂物种），并且花色形态在遗传上存在分化。然而，最强的遗传分化模式与种群中的精细尺度空间 - 地形隔离相关，有五个地形 - 遗传亚种群，花粉与种子传播距离比为4.32。我们的结果与在更大尺度上发现的类似的强烈空间遗传隔离模式一致：伊比利亚东南部一个分支内种群的系统地理学分化和系统发育关系。尽管花冠对蜜蜂传粉有极端的特化，但空间隔离似乎是驱动金鱼草短期和长期分化的主要因素。我们认为，对快速进化早期阶段的全面理解需要对精细尺度的进化驱动因素进行详细研究，包括空间隔离（地形）和生态因素（如传粉动物群）。
