Soukup Ales, Seago James L, Votrubová Olga
Department of Plant Physiology, Charles University, Vinicná 5, Prague 128 44, Czech Republic.
Ann Bot. 2005 Sep;96(3):379-85. doi: 10.1093/aob/mci190. Epub 2005 Jun 19.
The anatomical structure and development of adventitious roots were analysed in the basal monocotyledon, Acorus calamus, to determine to what extent those features are related to phylogenetic position.
Root specimens were harvested and sectioned, either with a hand microtome or freehand, at varying distances from the root tip and examined under the microscope using a variety of staining techniques.
Roots of Acorus calamus possess a unique set of developmental characteristics that produce some traits similar to those of another basal angiosperm group, Nymphaeales. The root apical meristem organization seems to be intermediate between that of a closed and an open monocotyledonous root apical meristem organization. The open-type root apical meristem consists of a curved zone of cortical initials and epidermal initials overlying the vascular cylinder initials; the epidermal part of the meristem varies in its association with the cortical initials and columellar initials of the promeristem. The cortex develops an endodermis with only Casparian bands, a dimorphic exodermis with Casparian bands and suberin lamellae, and a polygonal aerenchyma by differential expansion, as also observed in the Nymphaeales and some dicotyledonous species. The stele has characteristics like those of members of the Nymphaeaceae.
Specific anatomical and developmental attributes of Acorus roots seem to be related to the phylogenetic position of this genus.
分析了基部单子叶植物菖蒲不定根的解剖结构和发育情况，以确定这些特征与系统发育位置的相关程度。
采集根标本，用手动切片机或徒手切片，在距根尖不同距离处切片，并使用多种染色技术在显微镜下观察。
菖蒲的根具有一组独特的发育特征，产生了一些与另一个基部被子植物类群睡莲目相似的性状。根顶端分生组织的组织形式似乎介于封闭型和开放型单子叶植物根顶端分生组织之间。开放型根顶端分生组织由覆盖在维管柱原始细胞上的弯曲的皮层原始细胞区和表皮原始细胞组成；分生组织的表皮部分与原分生组织的皮层原始细胞和中柱原始细胞的联系各不相同。皮层通过差异扩展形成仅具凯氏带的内皮层、具凯氏带和栓质化层的二型外皮层以及多边形通气组织，睡莲目和一些双子叶植物物种中也观察到这种情况。中柱具有睡莲科成员的特征。
菖蒲根的特定解剖和发育特征似乎与其属的系统发育位置有关。
