PHYLOGENY OF THE CARYOPHYLLALES SENSU LATO: REVISITING HYPOTHESES ON POLLINATION BIOLOGY AND PERIANTH DIFFERENTIATION IN THE CORE CARYOPHYLLALES
PHYLOGENY OF THE CARYOPHYLLALES SENSU LATO: REVISITING HYPOTHESES ON POLLINATION BIOLOGY AND PERIANTH DIFFERENTIATION IN THE CORE CARYOPHYLLALES
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DOI：
10.1086/597785
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发表时间：
2009-06-01
影响因子：
2.3
通讯作者：
Soltis, Pamela S.
中科院分区：
文献类型：
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作者：
Brockington, Samuel F.;Alexandre, Roolse;Soltis, Pamela S.
分子系统发育学彻底改变了我们对石竹目（Caryophyllales）的理解，但许多亲缘关系仍然不确定，尤其是在更深入的层面。我们对包含9个质体基因（约12,000个碱基对）、2个核基因（约5000个碱基对）以及质体反向重复序列（约24,000个碱基对）的单独和组合数据集进行了简约分析和最大似然分析，对36种石竹目植物和4个外类群进行分析的组合长度为42,006个碱基对。我们得到了对该目深层次亲缘关系的有力支持。两个主要的亚分支得到了很好的支持，即非核心石竹目和核心石竹目；棒木属（Rhabdodendron）之后是希蒙得木属（Simmondsia），它们是核心石竹目的姐妹群，石莲属（Limeum）和闭籽花属（Stegnosperma）依次是“球状内含物”分支的姐妹群，吉粟草属（Gisekia）是一个独特的谱系，在“针晶体”分支中与商陆属（Rivina）有明显的区分，并且商陆属和商陆科（Phytolaccaceae）是不同的谱系，商陆属是紫茉莉科（Nyctaginaceae）的姐妹群。肉叶刺茎藜属（Sarcobatus）的分类位置以及马齿苋类群内部的亲缘关系仍然存在问题。在后者中，盐蓬属（Halophytum）是落葵科（Basellaceae）和刺戟科（Didiereaceae）的姐妹群，包含马齿苋属（Portulaca）、土人参属（Talinum）和仙人掌科（Cactaceae）的分支得到了很好的支持。经典假说认为，早期的石竹目植物是在传粉者稀少的开放、干燥、边缘环境中进化的，因此，石竹目的祖先花是风媒传粉的，花被无分化。根据我们的系统发育研究，我们重新评估了这些假说，发现风媒传粉作为祖先状态几乎没有得到支持；然而，早期的石竹目花被认为具有无分化的花被。推测随后至少有9次花被分化的起源。我们讨论了花被分化独立起源的证据，并强调了这种模式为进化发育遗传学领域提供的研究机会。
Molecular phylogenetics has revolutionized our understanding of the Caryophyllales, and yet many relationships have remained uncertain, particularly at deeper levels. We have performed parsimony and maximum likelihood analyses on separate and combined data sets comprising nine plastid genes (similar to 12,000 bp), two nuclear genes (similar to 5000 bp), and the plastid inverted repeat (similar to 24,000 bp), giving a combined analyzed length of 42,006 bp for 36 species of Caryophyllales and four outgroups. We have recovered strong support for deep-level relationships across the order. Two major subclades are well supported, the noncore and core Caryophyllales; Rhabdodendron followed by Simmondsia are sisters to the core Caryophyllales, Limeum and Stegnosperma are successive sisters to the "globular inclusion'' clade, Gisekia is a distinct lineage well separated from Rivina within the "raphide'' clade, and Rivina and Phytolaccaceae are disparate lineages, with Rivina sister to Nyctaginaceae. The placement of Sarcobatus and relationships within the portulacaceous cohort remain problematic. Within the latter, Halophytum is sister to Basellaceae and Didiereaceae, and the clade comprising Portulaca, Talinum, and Cactaceae is well supported. Classical hypotheses argued that the early Caryophyllales had evolved in open, dry, marginal environments at a time when pollinators were scarce, and, as such, the ancestral caryophyllid flower was wind pollinated with an undifferentiated perianth. We reevaluated these hypotheses in light of our phylogeny and find little support for anemophily as the ancestral condition; however, the early caryophyllid flower is suggested to have possessed an undifferentiated perianth. A subsequent minimum of nine origins of differentiated perianth is inferred. We discuss the evidence for independent origins of differentiated perianth and highlight the research opportunities that this pattern offers to the field of evolutionary developmental genetics.