Lima Jacqueline S, Telles Mariana P C, Chaves Lázaro J, Lima-Ribeiro Matheus S, Collevatti Rosane G
Laboratório de Genética & Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal de Goiás, PO Box 131, 74001-970, Goiânia, Brazil.
Escola de Ciências Agrárias e Biológicas, Pontifícia Universidade Católica de Goiás, 74605-010, Goiânia, Brazil.
Ann Bot. 2017 Mar 1;119(4):645-657. doi: 10.1093/aob/mcw257.
Cyclic glaciations were frequent throughout the Quaternary and this affected species distribution and population differentiation worldwide. The present study reconstructed the demographic history and dispersal routes of Eugenia dysenterica lineages and investigated the effects of Quaternary climate change on its spatial pattern of genetic diversity.
A total of 333 individuals were sampled from 23 populations and analysed by sequencing four regions of the chloroplast DNA and the internal transcribed spacer of the nuclear DNA. The analyses were performed using a multi-model inference approach based on ecological niche modelling and statistical phylogeography.
Coalescent simulation showed that population stability through time is the most likely scenario. The palaeodistribution dynamics predicted by the ecological niche models revealed that the species was potentially distributed across a large area, extending over Central-Western Brazil through the last glaciation. The lineages of E. dysenterica dispersed from Central Brazil towards populations at the northern, western and south-eastern regions. A historical refugium through time may have favoured lineage dispersal and the maintenance of genetic diversity.
The results suggest that the central region of the Cerrado biome is probably the centre of distribution of E. dysenterica and that the spatial pattern of its genetic diversity may be the outcome of population stability throughout the Quaternary. The lower genetic diversity in populations in the south-eastern Cerrado biome is probably due to local climatic instability during the Quaternary.
在整个第四纪，周期性冰川作用频繁发生，这影响了全球物种分布和种群分化。本研究重建了痢疾番樱桃谱系的种群历史和扩散路线，并研究了第四纪气候变化对其遗传多样性空间格局的影响。
从23个种群中总共采集了333个个体，并通过对叶绿体DNA的四个区域和核DNA的内转录间隔区进行测序来进行分析。分析采用基于生态位建模和统计系统地理学的多模型推断方法。
溯祖模拟表明，种群随时间保持稳定是最有可能的情况。生态位模型预测的古分布动态表明，该物种可能分布在大片区域，在末次冰期时延伸至巴西中西部。痢疾番樱桃的谱系从巴西中部向北部、西部和东南部的种群扩散。一个长期存在的避难所可能有利于谱系扩散和遗传多样性的维持。
结果表明，塞拉多生物群落的中部地区可能是痢疾番樱桃的分布中心，其遗传多样性的空间格局可能是第四纪期间种群稳定的结果。塞拉多生物群落东南部种群遗传多样性较低可能是由于第四纪期间当地气候不稳定所致。
