Sukhorukov Alexander P, Mavrodiev Evgeny V, Struwig Madeleen, Nilova Maya V, Dzhalilova Khalima Kh, Balandin Sergey A, Erst Andrey, Krinitsyna Anastasiya A
Department of Higher Plants, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
PLoS One. 2015 Feb 24;10(2):e0117974. doi: 10.1371/journal.pone.0117974. eCollection 2015.
The core Caryophyllales consist of approximately 30 families (12,000 species) distributed worldwide. Many members evolved one-seeded or conjoined fruits, but their origin and structural diversity have not been investigated. A comparative anatomical investigation of the one-seeded fruits within the core Caryophyllales was conducted. The origin of the one-seeded fruits and the evolutionary reconstructions of some carpological characters were traced using a tree based on rbcl and matK data in order to understand the ancestral characters and their changes. The one-seeded fruit type is inferred to be an ancestral character state in core Caryophyllales, with a subsequent increase in the seed number seen in all major clades. Most representatives of the 'Earlier Diverging' clade are distinguished in various carpological traits. The organization of the pericarp is diverse in many groups, although fruits with a dry, many-layered pericarp, consisting of sclerenchyma as outer layers and a thin-walled parenchyma below, with seeds occupying a vertical embryo position, are likely ancestral character states in the core Caryophyllales clade. Several carpological peculiarities in fruit and seed structure were discovered in obligate one-seeded Achatocarpaceae, Chenopodiaceae, Nyctaginaceae, Seguieriaceae and Sarcobataceae. The horizontal embryo evolved in only certain groups of Chenopodiaceae. The bar-thickening of endotegmen cells appears to be an additional character typical of core Caryophyllales. The syncarpy-to-lysicarpy paradigm in Caryophyllaceae needs to be reinterpreted.
核心石竹目约由30个科（12000种）组成，分布于全球。许多成员演化出单种子或合生果实，但其起源和结构多样性尚未得到研究。对核心石竹目内的单种子果实进行了比较解剖学研究。利用基于rbcl和matK数据构建的系统树，追溯了单种子果实的起源以及一些果实学特征的进化重建，以了解祖先特征及其变化。推断单种子果实类型是核心石竹目的一个祖先特征状态，随后在所有主要分支中种子数量增加。“较早分化”分支的大多数代表在各种果实学特征上有所不同。许多类群中果皮的组织各不相同，尽管具有干燥、多层果皮的果实，外层由厚壁组织组成，下方为薄壁薄壁组织，种子处于垂直胚位置，可能是核心石竹目分支的祖先特征状态。在专性单种子的苋科、藜科、紫茉莉科、刺戟科和肉叶刺茎藜科中发现了果实和种子结构的几个果实学特性。水平胚仅在藜科的某些类群中演化。内种皮细胞的条带状加厚似乎是核心石竹目的另一个典型特征。石竹科中合心皮到离生心皮的模式需要重新解释。
