Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.
Mol Phylogenet Evol. 2013 Sep;68(3):498-501. doi: 10.1016/j.ympev.2013.04.020. Epub 2013 May 3.
Foundation tree species define the structure of forest habitat and influence their ecosystem dynamics. However, there is limited understanding of both the patterns and timing of population fluctuations in foundation trees and how they vary among geographical regions. We have reconstructed the demographic history of five genetically distinct populations of the Tasmanian blue gum (Eucalyptus globulus ssp. globulus) at the species and regional levels, using three nuclear loci sequenced from 104 individuals. Analysis using a Bayesian skyline plot indicated that the species experienced two periods of expansion, commencing in the Pliocene. Regional analyses showed that island populations expanded earlier, but that the rate of expansion was relatively slow when compared to that of the mainland group. This highlights the need for local demographic history to be taken into account when inferring local adaptation for candidate genes. Population growth throughout the Quaternary signals the ability of the species to persist and thrive under the predominantly harsh conditions of this period.
基础树种决定了森林栖息地的结构，并影响其生态系统动态。然而，对于基础树种种群波动的模式和时间，以及它们在地理区域之间的差异，我们的了解有限。我们使用从 104 个个体中测序的三个核基因座，在种和区域水平上重建了五种遗传上不同的塔斯马尼亚蓝桉（Eucalyptus globulus ssp. globulus）种群的种群历史。使用贝叶斯天际线图进行分析表明，该物种经历了两次扩张期，始于上新世。区域分析表明，岛屿种群的扩张更早，但与大陆种群相比，扩张速度相对较慢。这凸显了在推断候选基因的局部适应性时，需要考虑当地的种群历史。整个第四纪的种群增长表明，该物种有能力在这一时期主要的恶劣条件下生存和繁衍。
