Hmeljevski Karina Vanessa, Nazareno Alison Gonçalves, Leandro Bueno Marcelo, Dos Reis Maurício Sedrez, Forzza Rafaela Campostrini
Rio de Janeiro Botanical Garden Rio de Janeiro RJ Brazil.
Department of Botany University of São Paulo São Paulo SP Brazil.
Ecol Evol. 2017 May 23;7(13):4704-4716. doi: 10.1002/ece3.3038. eCollection 2017 Jul.
Here, we explore the historical and contemporaneous patterns of connectivity among populations located on granitic inselbergs in an Ocbil landscape within the Brazilian Atlantic Forest, using both nuclear and chloroplast microsatellite markers. Beyond to assess the population genetic structure, we built species distribution models across four periods (current conditions, mid-Holocene, Last Glacial Maximum [LGM], and Last Interglacial) and inferred putative dispersal corridors using a least-cost path analysis to elucidate biogeographic patterns. Overall, high and significant genetic divergence was estimated among populations for both nuclear and plastid DNA (Φ = 0.463 and Φ = 0.961, respectively, < .001). For nuclear genome, almost total absence of genetic admixture among populations and very low migration rates were evident, corroborating with the very low estimates of immigration and emigration rates observed among populations. Based on the cpDNA results, putative dispersal routes in Sugar Loaf Land across cycles of climatic fluctuations in the Quaternary period revealed that the populations' connectivity changed little during those events. Genetic analyses highlighted the low genetic connectivity and long-term persistence of populations, and the founder effect and genetic drift seemed to have been very important processes that shaped the current diversity and genetic structure observed in both genomes. The genetic singularity of each population clearly shows the need for in situ conservation of all of them.
在这里，我们利用核微卫星标记和叶绿体微卫星标记，探索了巴西大西洋森林中奥比尔景观内花岗岩孤山上种群之间的历史和当代连通模式。除了评估种群遗传结构外，我们还构建了四个时期（当前条件、全新世中期、末次盛冰期[LGM]和末次间冰期）的物种分布模型，并使用最小成本路径分析推断假定的扩散走廊，以阐明生物地理模式。总体而言，核DNA和质体DNA在种群间的遗传分化都很高且显著（分别为Φ = 0.463和Φ = 0.961，< 0.001）。对于核基因组，种群间几乎完全没有遗传混合，迁移率非常低，这与在种群中观察到的极低的迁入和迁出率估计值相符。基于叶绿体DNA的结果，在第四纪气候波动周期中，面包山土地上假定的扩散路线表明，在这些事件中种群的连通性变化不大。遗传分析突出了种群的低遗传连通性和长期持续性，奠基者效应和遗传漂变似乎是塑造当前在两个基因组中观察到的多样性和遗传结构的非常重要的过程。每个种群的遗传独特性清楚地表明需要对它们全部进行原地保护。
