Embracing discordance: Phylogenomic analyses provide evidence for allopolyploidy leading to cryptic diversity in a Mediterranean Campanula (Campanulaceae) clade
Embracing discordance: Phylogenomic analyses provide evidence for allopolyploidy leading to cryptic diversity in a Mediterranean Campanula (Campanulaceae) clade
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DOI：
10.1111/evo.13203
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发表时间：
2017-04-01
期刊：
影响因子：
3.3
通讯作者：
Cellinese, Nico
中科院分区：
文献类型：
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作者：
Crowl, Andrew A.;Myers, Cody;Cellinese, Nico
地中海盆地拥有大量的生物多样性，其中很大一部分是该区域特有的。在这里，我们提出了一个深入的研究被子植物种复合体，其中的神秘的分类多样性已被假设。具体来说，我们专注于四个目前公认的物种在Roucela复杂，一个良好的支持支在桔梗科/桔梗亚科：风铃草creutzbursti，C。drabifolia，C. erinus和C. simulans。这项研究采用了一种新的基因组方法，利用接近完整的质体和130个核基因座，揭示了隐藏的多样性和测试假设杂交和多倍体在这个分支。基因组大小估计恢复四倍体和二倍体谱系内目前公认的，广泛的物种C。erinus，显示出东西向的地理格局。虽然基因组数据清楚地区分这两种细胞型，我们未能辨别形态差异。一个神秘的二倍体谱系的形成，分布在地中海东部，被假设是一个异源多倍体事件的结果，其中一个父母的形态被保留。四倍体C. erinus和C. Creutzbursts（也是四倍体）被认为是亲本谱系。我们的研究结果强调了目标富集方法用于获得基因组数据集以彻底评估物种多样性的实用性，以及仔细考虑这些数据集内基因树不一致性的重要性。
The Mediterranean Basin harbors a remarkable amount of biodiversity, a high proportion of which is endemic to this region. Here, we present an in-depth study of an angiosperm species complex, in which cryptic taxonomic diversity has been hypothesized. Specifically, we focus on four currently recognized species in the Roucela complex, a well-supported clade in the Campanulaceae/Campanuloideae: Campanula creutzburgii, C. drabifolia, C. erinus, and C. simulans. This study takes a phylogenomic approach, utilizing near-complete plastomes and 130 nuclear loci, to uncover cryptic diversity and test hypotheses regarding hybridization and polyploidy within this clade. Genome size estimates recovered tetraploid and octoploid lineages within the currently recognized, widespread species C. erinus, showing an east-west geographic pattern. Though genomic data clearly differentiate these two cytotypes, we failed to discern morphological differences. The formation of a cryptic octoploid lineage, distributed across the eastern Mediterranean, is hypothesized to be the result of an allopolyploid event in which one parental morphology is retained. The tetraploid C. erinus and C. creutzburgii (also a tetraploid) are implicated as parental lineages. Our results highlight the utility of target-enrichment approaches for obtaining genomic datasets for thorough assessments of species diversity and the importance of carefully considering gene-tree discordance within such datasets.