Flores-Rentería Lluvia, Rymer Paul D, Ramadoss Niveditha, Riegler Markus
Department of Biology San Diego State University San Diego CA USA.
Hawkesbury Institute for the Environment Western Sydney University Penrith NSW Australia.
Ecol Evol. 2021 Sep 30;11(21):14828-14842. doi: 10.1002/ece3.8169. eCollection 2021 Nov.
We have investigated the impact of recognized biogeographic barriers on genetic differentiation of grey box (), a common and widespread tree species of the family Myrtaceae in eastern Australian woodlands, and its previously proposed four subspecies , , , and . A range of phylogeographic analyses were conducted to examine the population genetic differentiation and subspecies genetic structure in in relation to biogeographic barriers. Slow evolving markers uncovering long term processes (chloroplast DNA) were used to generate a haplotype network and infer phylogeographic barriers. Additionally, fast evolving, hypervariable markers (microsatellites) were used to estimate demographic processes and genetic structure among five geographic regions (29 populations) across the entire distribution of . Morphological features of seedlings, such as leaf and stem traits, were assessed to evaluate population clusters and test differentiation of the putative subspecies. Haplotype network analysis revealed twenty chloroplast haplotypes with a main haplotype in a central position shared by individuals belonging to the regions containing the four putative subspecies. Microsatellite analysis detected the genetic structure between Queensland (QLD) and New South Wales (NSW) populations, consistent with the McPherson Range barrier, an east-west spur of the Great Dividing Range. The substructure was detected within QLD and NSW in line with other barriers in eastern Australia. The morphological analyses supported differentiation between QLD and NSW populations, with no difference within QLD, yet some differentiation within NSW populations. Our molecular and morphological analyses provide evidence that several geographic barriers in eastern Australia, including the Burdekin Gap and the McPherson Range have contributed to the genetic structure of . Genetic differentiation among populations supports the recognition of some but not all the four previously proposed subspecies, with being the most differentiated.
我们研究了公认的生物地理屏障对灰箱树（Eucalyptus moluccana）遗传分化的影响。灰箱树是澳大利亚东部林地桃金娘科一种常见且分布广泛的树种，以及之前提出的四个亚种（E. moluccana subsp. moluccana、E. moluccana subsp. elata、E. moluccana subsp. queenslandica和E. moluccana subsp. acmenoides）。我们进行了一系列系统发育地理学分析，以研究灰箱树种群遗传分化和亚种遗传结构与生物地理屏障的关系。利用揭示长期过程的缓慢进化标记（叶绿体DNA）生成单倍型网络并推断系统发育地理屏障。此外，还使用快速进化的高变标记（微卫星）来估计整个灰箱树分布范围内五个地理区域（29个种群）的种群动态过程和遗传结构。对幼苗的形态特征，如叶片和茎的性状进行评估，以评估种群聚类并检验假定亚种的分化情况。单倍型网络分析揭示了20种叶绿体单倍型，其中一个主要单倍型位于中心位置，为包含四个假定亚种的区域的个体所共有。微卫星分析检测到昆士兰（QLD）和新南威尔士（NSW）种群之间的遗传结构，这与大分水岭东西走向的支脉麦克弗森山脉屏障一致。在昆士兰和新南威尔士内部检测到亚结构，这与澳大利亚东部的其他屏障相符。形态学分析支持昆士兰和新南威尔士种群之间的分化，昆士兰内部没有差异，但新南威尔士种群内部存在一些分化。我们的分子和形态学分析提供了证据，表明澳大利亚东部的几个地理屏障，包括伯德金峡谷和麦克弗森山脉，对灰箱树的遗传结构产生了影响。灰箱树种群之间的遗传分化支持了对之前提出的四个亚种中部分（而非全部）亚种的认可，其中E. moluccana subsp. queenslandica的分化最为明显。
