Abstract

Finding morphological differences between cytotypes that are stable throughout their geographical range is important for understanding evolution of polyploid complexes. The ancient monocot lineage Acorus includes two groups, of which A. calamus s.l., an important medicinal plant, is a polyploid complex with a centre of diversity in Asia. European plants are sterile triploids introduced by humans. An early study suggested that plants from temperate Asia are tetraploids, but subsequent work revealed diploids and triploids rather than tetraploids in Asiatic Russia; however, cytotype diversity in Western Siberia is insufficiently known. We document the occurrence of diploids and triploids in Western Siberia. Triploids that do not differ in genome size from European Acorus are abundant in the valley of the river Ob where the ability for extensive vegetative propagation provides ecological advantages. An isolated population of aneuploid triploids with 33 chromosomes is found outside the Ob valley. Flow cytometry provides an efficient tool for identification of aneuploid plants in Acorus. All triploids are sterile, but their flowers develop uniform parthenocarpic fruits. Fruits of diploids usually vary in size within a spadix depending on the number of developing seeds. In contrast to North America, where the native diploid plants differ from the introduced triploids by the absence of a secondary midrib of the ensiform leaf blade, Siberian diploids are similar to triploids in possessing a secondary midrib. We confirm that diploids differ from triploids in the size of air lacunae in leaves, which is determined by cell number rather than cell size in septa of aerenchyma. A combination of spathe width and spadix length measured after the male stage of anthesis shows different (slightly overlapping) patterns of variation between diploids and triploids in our material.

中文翻译：

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西西伯利亚南部，不育植物中单性结实的二倍体和三倍体sterile蒲（Acoraceae）的形态学特征和非整倍性的发生

摘要

发现在整个地理范围内稳定的细胞类型之间的形态学差异对于理解多倍体复合体的进化很重要。古代单子叶植物世系Acorus分为两组，其中重要的药用植物A. calamus sl是一种多倍体复合体，在亚洲具有多样性的中心。欧洲植物是人类引入的不育三倍体。一项早期研究表明，亚洲温带地区的植物是四倍体，但随后的工作揭示了在亚洲俄罗斯，二倍体和三倍体而不是四倍体。但是，西伯利亚西部的细胞类型多样性知之甚少。我们记录了西伯利亚西部二倍体和三倍体的发生。基因组大小与欧洲Acorus相同的三倍体鄂毕河的山谷中植物丰富，能够进行广泛的营养繁殖，因此具有生态优势。在Ob山谷外发现了一个具有33条染色体的非整倍体三倍体。流式细胞术为鉴定Acorus中非整倍体植物提供了有效的工具。所有三倍体都是不育的，但它们的花会长出单性结实的果实。二倍体的果实通常在茎秆中的大小取决于发育中种子的数量。与北美不同，当地的二倍体植物与引入的三倍体的不同之处在于，没有梭形叶片的次生中脉，西伯利亚二倍体类似于具有次生中脉的三倍体。我们确认，二倍体与三倍体在叶片中空气腔的大小上有所不同，这取决于细胞数量而不是气孔隔中的细胞大小。在雄性花期后测量的茎宽和茎秆长度的组合显示出我们材料中二倍体和三倍体之间差异的不同（略有重叠）模式。