Phylogenetic analyses and perianth evolution in basal angiosperms
Phylogenetic analyses and perianth evolution in basal angiosperms
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DOI：
10.2307/3298579
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发表时间：
2003-01
影响因子：
1.9
通讯作者：
M. Zanis;P. Soltis;Y. Qiu;E. Zimmer;D. Soltis
中科院分区：
文献类型：
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作者：
M. Zanis;P. Soltis;Y. Qiu;E. Zimmer;D. Soltis
我们采用分区方法，利用来自所有三个基因组（叶绿体 - atpB、rbcL；细胞核 - 18S rDNA、26S rDNA；线粒体 - matR、atpA）的六个基因的序列，对最基部的现存被子植物进行了系统发育分析。对分区数据进行简约分析和最大似然分析所得到的树是相同的。我们发现对最早分支的被子植物有很强的支持（每个节点100%）：无油樟科、睡莲科以及木兰藤目分支（八角科、五味子科、腺齿木科、木兰藤科）。尽管大多数近期使用多个基因的研究对其余基部被子植物（金鱼藻科、金粟兰科、白樟目（=林仙目）、胡椒目、单子叶植物、木兰目、樟目）之间的关系分辨率和支持度较差，但通过分区，我们发现这些分支之间的自举支持率很高（>90%）。白樟目和胡椒目形成一个有很强支持（100%）的姐妹群，而这个姐妹群又是一个有很好支持（100%）的樟目和木兰目分支的姐妹群。白樟目 + 胡椒目以及木兰目 + 樟目形成一个有很好支持的木兰类分支。金鱼藻科被强烈支持（100%）为单子叶植物的姐妹群；单子叶植物/金鱼藻科分支被很好地支持（86%）为所有其余被子植物（金粟兰科、木兰类分支和真双子叶植物）的姐妹群。完整的26S rDNA序列的加入显然对这种内部支持的增加有贡献。我们利用我们的被子植物系统发育假说，研究了花被叶序、基数和分化的多样化。对于无油樟科、睡莲科、木兰藤目等级的每个节点，祖先花被叶序和基数是不明确的；然而，未分化的花被被重建为被子植物的祖先状态。三基数和轮生花被叶序在基部被子植物花被进化中起了重要作用，并代表了由除无油樟、睡莲科和木兰藤目之外的所有被子植物组成的大分支的祖先状态。分化的花被显然已经多次进化。
Using a compartmentalization approach, we conducted phylogenetic analyses of the basalmost extant angiosperms using sequences from six genes (over 12,000 bp per taxon) from all three genomes (chloroplast-atpB, rbcL; nuclear- 18S rDNA, 26S rDNA; mitochondrial-matR, atpA). Trees resulting from parsimony and maximum likelihood analyses of the compartmentalized data are identical. We find strong support (100% for each node) for the earliest-branching angiosperms: Amborellaceae, Nymphaeaceae, and an Austrobaileyales clade (Illiciaceae, Schisandraceae, Trimeniaceae, Austrobaileyaceae). Whereas most recent studies using multiple genes provided poor resolution and support for relationships among the remaining basal angiosperms (Ceratophyllaceae, Chloranthaceae, Canellales ( = Winterales), Piperales, monocots, Magnoliales, Laurales), with compartmentalization, we find high levels (> 90%) of bootstrap support for relationships among these clades. Canellales and Piperales form a strongly supported (100%) sister group that is, in turn, sister to a well-supported (100%) clade of Laurales and Magnoliales. Canellales + Piperales and Magnoliales + Laurales form a well-supported magnoliid clade. Ceratophyllaceae are strongly supported (100%) as sister to the monocots; the monocot/Ceratophyllaceae clade is well supported (86%) as sister to all remaining angiosperms (Chloranthaceae, the magnoliid clade, and eudicots). The addition of entire 26S rDNA sequences clearly contributed to this increased internal support. We examined the diversification of perianth phyllotaxis, merosity, and differentiation using our phylogenetic hypothesis for angiosperms. Ancestral perianth phyllotaxis and merosity are equivocal for each node of the Amborellaceae, Nymphaeaceae, Austrobaileyales grade; however, an undifferentiated perianth is reconstructed as the ancestral state for the angiosperms. Trimery and whorled perianth phyllotaxis have played a major role in basal angiosperm perianth evolution and represent the ancestral states for the large Glade comprising all angiosperms other than Amborella, Nymphaeaceae, and Austrobaileyales. A differentiated perianth has apparently evolved multiple times.