Because naturalized and invasive plant species have disproportionately smaller genome sizes compared to all angiosperms, genome size has been proposed as a general predictor of invasiveness. The family Cactaceae includes some of the most important invasive species worldwide, and it is one of the plant families with lowest number of genome size estimations. The main goal of this study was to explore possible correlations between genome size and invasiveness in Cactaceae, and between genome size and seed size and weight, traits previously linked with invasiveness. Propidium iodide flow cytometry was used to estimate the genome size from seeds (mostly) of 256 taxa of Cactaceae (32 of which are known to be invasive, and 13 are considered potentially invasive), and seed size, weight and mass were measured or obtained from previous work. Contrary to expectation, no significant differences were observed in genome size among categories of invasion, suggesting that genome size alone is not a reliable predictor of invasiveness in Cactaceae. Also, no correlations were observed between genome size and the studied seed traits when the whole dataset was considered. At a finer scale, in Opuntioideae, positive significant correlations were observed between genome size and the seed traits studied, and in Cacteae, the opposite trend was observed. Since Cactaceae species possess low rates of metabolism, selection towards traits linked with genome size may not have been favoured irrespective of the invasive strategy. The large number of genome size estimates reported in this study offers great opportunities for studying the evolution of genome size in this family and for exploring possible correlations between genome size and geographical, environmental and phenotypic traits.

由于与所有被子植物相比，归化和入侵的植物物种的基因组大小不成比例地较小，因此已提出基因组大小作为入侵性的一般预测指标。仙人掌科包括世界上一些最重要的入侵物种，它是估计基因组大小数量最少的植物科之一。这项研究的主要目的是探索仙人掌科中基因组大小与侵袭性之间，基因组大小与种子大小与重量之间的可能相关性，这些特征以前与侵害性相关。碘化丙啶流式细胞仪用于估计256种仙人掌科的种子（主要是种子）的基因组大小（其中32种已知具有入侵性，而13种被认为具有潜在入侵性），并测量或获得了种子的大小，重量和质量。从以前的工作。与预期相反，入侵类别之间的基因组大小没有观察到显着差异，这表明仅基因组大小并不是仙人掌科入侵性的可靠预测指标。而且，当考虑整个数据集时，在基因组大小和所研究的种子性状之间没有观察到相关性。在较小的规模上，在仙人掌科中，观察到基因组大小与所研究的种子性状之间存在显着的正相关，而在仙人掌科中，则观察到相反的趋势。由于仙人掌科物种的新陈代谢率较低，因此无论入侵策略如何，都倾向于不倾向于选择与基因组大小相关的性状。