Plastome phylogenomic analysis of Torreya (Taxaceae)
Plastome phylogenomic analysis of Torreya (Taxaceae)
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香榧（红豆杉科）的质体系统发育分析
DOI：
10.1111/jse.12482
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发表时间：
2019-11-01
影响因子：
3.7
通讯作者：
Sun, Yan-Xia
中科院分区：
文献类型：
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作者：
Zhang, Xu;Zhang, Hua-Jie;Sun, Yan-Xia
香椿属(Torreya Arn.)是红豆杉科(Taxaceae)的一个小属，由6个种组成，分布于北美和东亚。尽管只使用了几个DNA片段或物种，但之前已经进行了几项系统发育研究，以揭示该属之间的关系。在本研究中，我们测序了五个香椿质体体的序列，并将这些序列与该属现有的两个质体体相结合，以研究香椿属内的质体组进化和系统发育关系。所有测序的香椿质体体共有82个蛋白质编码基因、4个核糖体RNA基因和31个转移RNA基因。利用最大似然框架进行系统发育分析，包括香椿属所有种的82个基因、17个分类单元组成的数据集，将香椿属解析为一个单系支系。属内有较强的亲缘关系，包括早期分叉的T.jackii Chun、两个姊妹对T.fargesii Franch.-T.nucifera(L.)西博尔德和祖克。和T.Grand is Fortune ex Lindl.-T.calfornica Torr.，以及包括T.fargesii var.在内的支系的单系。Yunnanensis、法氏针茅和金针菇。除了物种关系的推断外，还进行了分歧时间估计和生物地理分析。香椿的多样化程度估计约为8.9 Ma。地理区域的祖先状态重建表明，中国/北美东部是现存六种香椿最有可能的祖先区域。
Torreya Arn., a small genus of Taxaceae, consists of six species occurring in North America and eastern Asia. Several phylogenetic studies have previously been undertaken to reveal relationships within this genus, although only a few DNA segments or species were used. In the present study, we sequenced five Torreya plastomes and combined these with two existing plastomes from the genus to investigate plastome evolution and phylogenetic relationships within Torreya. All sequenced Torreya plastomes shared the same complement of 82 protein‐coding genes, 4 ribosomal RNA genes, and 31 transfer RNA genes. Phylogenetic inference using a maximum likelihood framework consisted of an 82‐gene, 17‐taxon dataset, including all species of Torreya, resolved Torreya as a monophyletic clade. Strongly supported relationships within the genus include the position of the early diverging T. jackii Chun, the two sister pairs T. fargesii Franch.–T. nucifera (L.) Siebold & Zucc. and T. grandis Fortune ex Lindl.–T. californica Torr., and the monophyly of the clade including T. fargesii var. yunnanensis, T. fargesii, and T. nucifera. In addition to the inference of species relationships, divergence time estimation and biogeographical analysis were carried out. The diversification of Torreya was estimated to be approximately 8.9 Ma. Ancestral state reconstruction of the geographical area suggested China/eastern North America as the most likely ancestral region for the six extant Torreya species.