Guo Xue-Min, Yu Ying-Ying, Bai Lan, Gao Rong-Fu
College of Life Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, China.
College of Biological Sciences, China Agricultural University, Beijing, China.
Front Plant Sci. 2017 Nov 30;8:1986. doi: 10.3389/fpls.2017.01986. eCollection 2017.
is a perennial herbaceous plant with great ornamental, botanical, ecological, and medicinal value. The pistil of is composed of two fused carpels with free central placenta and two separate styles. The placenta is a columnar structure extending about two-thirds the length of the maturing fruit, which is typical of the Caryophyllaceous. Traditionally, free central placenta is thought to have evolved from axial placenta by septal disappearance, and axial placenta to have occurred through fusion of conduplicate carpels with marginal placenta. However, the traditional opinion is becoming more and more inconsistent with the new data gained in recent research of angiosperm systematics. To clarify the origin of pistil, the present anatomical study was carried out. The results show that the vascular system of placenta is independent to that of the ovary wall in . Moreover, in the central part of placenta there are one or two amphicribral bundles, and correspondingly numerous ones in the pistil which supply the ovules/seeds. It is obvious that the central amphicribral bundles in placenta are comparable to the counterparts in branches but not to those in leaves or their derivatives. Therefore, it is reasonable to deduce that the placenta of was not derived from conduplicate carpels through fusion of collateral vascular bundles, and actually a floral axis with ovules/seeds laterally adhering. On the contrary, the ovary wall was the lateral appendages of the floral axis. The result of the present study is completely in agreement with Unifying Theory, in which the placenta is taken as an ovule-bearing branch. Except for , the similar vascular organization has been observed in placenta of numerous isolated taxa. But till now, it is uncertain that whether this vascular organization pattern is popular in the whole angiosperms or not. More intensive and extensive investigations are needed.
是一种具有很高观赏、植物学、生态学和药用价值的多年生草本植物。[植物名称]的雌蕊由两个合生心皮组成，具游离中轴胎座和两个分离的花柱。胎座是一种柱状结构，延伸至成熟果实长度的约三分之二，这是石竹科植物的典型特征。传统上，游离中轴胎座被认为是由隔膜消失从侧膜胎座演化而来，而侧膜胎座则是通过对折心皮与边缘胎座融合而产生。然而，传统观点越来越与被子植物系统发育近期研究中获得的新数据不一致。为了阐明[植物名称]雌蕊的起源，进行了本解剖学研究。结果表明，[植物名称]胎座的维管系统与子房壁的维管系统是独立的。此外，在胎座中央部分有一或两个周韧维管束，相应地在雌蕊中有许多维管束为胚珠/种子提供养分。显然，胎座中央的周韧维管束与枝中的维管束相当，而与叶或其衍生物中的维管束不同。因此，合理推断[植物名称]的胎座并非通过并生维管束融合从对折心皮衍生而来，实际上是一个带有侧向附着胚珠/种子的花轴。相反，子房壁是花轴的侧向附属物。本研究结果与统一理论完全一致，在该理论中胎座被视为一个着生胚珠的枝条。除了[植物名称]外，在许多孤立类群的胎座中也观察到了类似的维管组织。但到目前为止，尚不确定这种维管组织模式在整个被子植物中是否普遍。需要更深入和广泛的研究。
