Asexual reproduction has often been regarded as an evolutionary dead end, but asexual lineages (most notably those that are apomictic) are present in several angiosperm families and often comprise a large number of taxa, both widespread and endemic. Investigating correlations between genetic, environmental and taxonomic factors and the incidence of apomixis has represented a challenge for many years, with previous analyses frequently omitting one or more of these variables. Here, flow cytometric seed screening, cytological data and ecological variables have been integrated in a phylogenetic framework to create a comprehensive dataset for 229 of Asteraceae from the European Alps. Data were analysed using phylogenetically informed generalized linear mixed models (pMCMCglmm) where elevation, ploidy and phenology were assessed for their potential correlation with asexual reproduction and apomixis type. Although apomixis is not dominant among the species studied, our results confirm that an odd ploidy (e.g. 3x) and, to a lesser extent, an even polyploid level (i.e. 4x) significantly increase its probability, most probably due to chromosome misalignments during meiosis. The distribution of apomictic species does not correlate with elevation, and there is a weak correlation between early flowering initiation and aposporous apomixis. Although current and future changes in climate may severely impact the survival of the flora of the European Alps, asexual reproduction and polyploidization may prove to be, at least temporarily, lifelines for the survival of a species under the novel climatic conditions. Therefore, uncovering how apomicts and polyploids evolve and persist will be essential for understanding the ecology of the European Alps and hence informing future conservation strategies.

中文翻译：

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系统发育，海拔和倍性与欧洲阿尔卑斯山菊科无融合生殖发生率的相关性

无性生殖通常被认为是进化的死角，但无性血统（最显着的是无融合生殖的血统）存在于多个被子植物科中，通常包括大量的类群，既有广泛的又有地方性的。研究遗传，环境和分类学因素与无融合生殖的发生率之间的相关性一直是一项挑战，多年来，以往的分析经常忽略这些变量中的一个或多个。在这里，流式细胞仪种子筛选，细胞学数据和生态变量已整合到系统发育框架中，以创建来自欧洲阿尔卑斯山的229个菊科的综合数据集。使用系统发育信息广义线性混合模型（pMCMCglmm）分析数据，其中海拔，评估了倍性和物候学与无性繁殖和无融合生殖类型的潜在相关性。尽管无融合生殖在所研究的物种中并不占优势，但我们的结果证实了奇数倍性（例如3x），并且在较小程度上，均匀的多倍体水平（即4 x）会显着增加其概率，这很可能是由于减数分裂过程中染色体错位所致。无融合生殖物种的分布与海拔高度不相关，并且早期开花起始与无孔无融合生殖之间的相关性较弱。尽管当前和未来的气候变化可能会严重影响欧洲阿尔卑斯山植物区系的生存，但无性繁殖和多倍化可能至少在暂时性上是新气候条件下物种生存的生命线。因此，揭示无融合生殖和多倍体如何进化和持续存在对于了解欧洲阿尔卑斯山的生态并为未来的保护战略提供信息至关重要。