The Western Carpathians are traditionally recognized as one of the hotspots of temperate European biodiversity. The polyploid and apomictic group of Cotoneaster integerrimus s.l. is supposed to be particularly variable there, and this is also mirrored by taxonomy. We therefore examined the ploidal and reproductive pattern of C. integerrimus s.l. and its close relative Cotoneaster tomentosus in the Western Carpathians and compared it to that in the Bohemian Massif. Using flow cytometry, we detected tetraploid (468 individuals, 100 populations) and pentaploid (35 individuals, 11 populations) cytotypes, and eight additional mixed populations. The pentaploid cytotype was found exclusively in C. tomentosus, which only occurs in the Western Carpathians. A further flow cytometric seed screen (1114 seeds) revealed facultative apomixis (10.1% of sexual progeny) of tetraploid C. integerrimus s.l., whereas the pentaploid C. tomentosus was almost obligately apomictic. In addition, 3.8% of sexual progeny was formed with the contribution of an unreduced female gamete. Moreover, apomixis in tetraploids was further structured into distinct subtypes: pseudogamy (77.2%), autonomous apomixis (3.7%) and haploid parthenogenesis (0.3%). There were no significant differences in the proportions of sexual and asexual seeds between both species and geographic regions. Our comparative dataset from the Western Alps also included sexual diploids. For this reason, greater ploidal and reproductive variation may be expected in that region. The Western Carpathians therefore do not represent a centre of cytotype and reproductive variation of C. integerrimus s.l., and facultative apomixis is a reproductive strategy that predominates in both the Western Carpathians and the Bohemian Massif.

中文翻译：

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深入了解西喀尔巴阡山脉 Cotoneaster integerrimus 的细胞型和生殖难题

西喀尔巴阡山脉传统上被认为是欧洲温带生物多样性的热点地区之一。Cotoneaster integerrimus sl 的多倍体和无融合生殖群在那里应该特别多变，这也反映在分类学上。因此，我们检查了西喀尔巴阡山脉的 C. integerrimus sl 及其近亲 Cotoneaster tomentosus 的倍性和繁殖模式，并将其与波西米亚地块中的情况进行了比较。使用流式细胞术，我们检测到四倍体（468 个个体，100 个种群）和五倍体（35 个个体，11 个种群）细胞型，以及另外 8 个混合种群。五倍体细胞型仅在 C. tomentosus 中发现，仅发生在西喀尔巴阡山脉。进一步的流式细胞仪种子筛选（1114 粒种子）显示兼性无融合生殖（10. 1% 的四倍体 C. integerrimus sl 的有性后代），而五倍体 C. tomentosus 几乎是专性无融合生殖的。此外，3.8% 的有性后代是由未减少的雌配子形成的。此外，四倍体中的无融合生殖进一步分为不同的亚型：假配偶（77.2%）、自主无融合生殖（3.7%）和单倍体孤雌生殖（0.3%）。在物种和地理区域之间，有性种子和无性种子的比例没有显着差异。我们来自西阿尔卑斯山的比较数据集还包括有性二倍体。出于这个原因，该地区可能会出现更大的倍性和生殖变异。因此，西喀尔巴阡山脉并不代表 C. integerrimus sl 的细胞型和生殖变异中心，