Vanrell Maria Antònia, Novaes Letícia R, Afonso Ana, Arroyo Juan, Simón-Porcar Violeta
Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, 41012 Seville, Spain.
Centre for Functional Ecology, Associate Laboratory TERRA, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
AoB Plants. 2024 May 21;16(4):plae027. doi: 10.1093/aobpla/plae027. eCollection 2024 Jul.
is a taxonomic complex widespread in the Western Mediterranean basin. The complex is characterized by a high phenotypic and cytogenetic diversity, and by a unique three-dimensional heterostyly system that makes it an obligate outcrosser. We studied the patterns of genetic diversity and structure of populations throughout the entire distribution of with microsatellite markers. We analysed their relationships with various biological and ecological variables, including the morph ratio and sex organ reciprocity of populations measured with a novel multi-dimensional method. Populations consistently showed an approximate 1:1 morph ratio with high sex organ reciprocity and high genetic diversity. We found high genetic differentiation of populations, showing a pattern of isolation by distance. The Rif mountains in NW Africa were the most important genetic barrier. The taxonomic treatment within the group was not related to the genetic differentiation of populations, but to their environmental differentiation. Genetic diversity was unrelated to latitude, elevation, population size, niche suitability or breeding system. However, there was a clear influence of ploidy level on the genetic diversity of populations, and a seeming centre-periphery pattern in its distribution. Our results suggest that polyploidization events, high outcrossing rates, isolation by distance and important geographical barriers to gene flow have played major roles in the microevolutionary history of this species complex.
是一个分类学复合体，广泛分布于西地中海盆地。该复合体的特征是具有高度的表型和细胞遗传学多样性，以及独特的三维异型花柱系统，这使其成为专性异交植物。我们使用微卫星标记研究了该复合体整个分布范围内的遗传多样性模式和种群结构。我们分析了它们与各种生物学和生态变量的关系，包括用一种新颖的多维方法测量的种群的形态比例和性器官互作。种群始终呈现出近似1:1的形态比例，具有高性器官互作和高遗传多样性。我们发现种群间存在高度的遗传分化，呈现出隔离距离模式。非洲西北部的里夫山脉是最重要的遗传屏障。该类群内的分类处理与种群的遗传分化无关，而是与其环境分化有关。遗传多样性与纬度、海拔、种群大小、生态位适宜性或繁殖系统无关。然而，倍性水平对种群的遗传多样性有明显影响，并且在其分布上存在明显的中心-边缘模式。我们的结果表明，多倍体化事件、高异交率、隔离距离以及重要的基因流地理屏障在该物种复合体的微观进化历史中发挥了主要作用。
