Despite the increasing evidence that ploidy is a factor of importance for environmental adaptation, little work has hitherto been done about cytotype patterns in aquatic plants. We tested a set of hypotheses concerning the drivers of ploidy in macrophyte communities at worldwide scale, and also how ploidy state may be related to other attributes of aquatic plants such as community diversity, species range size and invasiveness. We built a global ploidy database with 1574 species (representing 45.0 % of the known total global pool) and allocated ploidy state to species occurring in 238 10 × 10° gridcells worldwide. We used Boosted Regression Trees Analysis to analyse the relationship of 16 global-scale spatial, landscape, environmental and biotic variables with ploidy state. Our results demonstrate that (1) Polyploid and mixed ploidy species occupied larger geographical ranges than haploid/diploid species. (2) There were contrasting latitudinal patterns between haploid/diploid and polyploid species with polyploidy increasing in importance with distance from the equator, while species richness measures also influenced ploidy state. (3) Climatic factors, especially temperature and evapotranspiration, are congruent with macrophyte species ploidy state, across the planet. Our data support the assertion that increased chromosome number is an adaptation associated with plant survival of harsh environmental conditions, especially in environmentally-stressed high latitudes. Our findings increase the generality of knowledge of the large-scale factors that drive cytotype patterns in vascular plant species at global scale. The ploidy database provides a resource to support further studies about the effects of varying environmental conditions on ploidy state in aquatic plants, at differing scales.

尽管越来越多的证据表明倍性是环境适应的一个重要因素，但迄今为止对水生植物细胞型模式的研究很少。我们测试了一组关于全球范围内大型植物群落倍性驱动因素的假设，以及倍性状态如何与水生植物的其他属性（例如群落多样性、物种范围大小和入侵性）相关。我们建立了一个包含 1574 个物种（占已知全球总库的 45.0%）的全球倍性数据库，并将倍性状态分配给发生在全球 238 个 10 × 10° 网格单元中的物种。我们使用 Boosted Regression Trees Analysis 来分析 16 个全球尺度的空间、景观、环境和生物变量与倍性状态的关系。我们的结果表明（1）多倍体和混合倍体物种比单倍体/二倍体物种占据更大的地理范围。(2) 单倍体/二倍体物种与多倍体物种之间存在对比的纬度模式，多倍体的重要性随着距赤道距离的增加而增加，而物种丰富度的测量也影响倍性状态。(3) 气候因素，特别是温度和蒸散量，与地球上的大型植物物种倍性状态一致。我们的数据支持这样一种断言，即增加的染色体数量是与植物在恶劣环境条件下生存相关的适应性，特别是在环境压力高的高纬度地区。我们的发现增加了在全球范围内驱动维管植物物种细胞型模式的大规模因素的知识的普遍性。