Ups and downs: genetic differentiation among populations of the Podocarpus (Podocarpaceae) species in Mesoamerica

The biogeographical history of Mesoamerican cloud forests is complex, encompassing a diverse and heterogeneous mixture of species with temperate and tropical origins. The dynamic geological landscape and climate change from the Miocene to the Pleistocene affected the distributions and composition of cloud forests in the region, and contributed to divergence events at different time scales. We assessed genetic variation of 29 populations of P. matudae, and closely related P. guatemalensis and P. oleifolius (Podocarpaceae) by sequencing 255 samples of the psbA-trnH and trnL-F intergenic spacer regions across the species ranges. We conducted phylogenetic, population and spatial genetic analyses as well as divergence time estimation and ecological niche modelling (ENM) to test the generality of demographic and genetic scenarios for cloud forest-adapted species. The results revealed genetic differentiation among species, with some individuals of P. oleifolius and P. guatemalensis placed in t...

中美洲云雾林的生物地理历史颇为复杂，涵盖了兼具温带与热带起源的多样且异质的物种类群。中新世至更新世期间的动态地质景观与气候变化，影响了该区域云雾林的分布与群落组成，并在不同时间尺度上推动了物种分化事件。我们针对马鲁达罗汉松（P. matudae）的29个种群，及其近缘物种危地马拉罗汉松（P. guatemalensis）与油叶罗汉松（P. oleifolius，均隶属于罗汉松科Podocarpaceae），通过对物种分布范围内的255份样本的psbA-trnH和trnL-F基因间隔区进行测序，评估了它们的遗传变异情况。我们开展了系统发育分析、种群遗传分析与空间遗传分析，同时进行了分化时间估算以及生态位模型（Ecological Niche Modelling, ENM）构建，以检验适应云雾林物种种群动态与遗传情景的普遍性。研究结果揭示了物种间的遗传分化，部分油叶罗汉松（P. oleifolius）与危地马拉罗汉松（P. guatemalensis）的个体被归入……