Mutation rate estimates for vegetatively reproducing organisms are rare, despite their frequent occurrence across the tree of life. Here we report mutation rate estimates in two vegetatively reproducing duckweed species, Lemna minor and Spirodela polyrhiza. We use a modified approach to estimating mutation rates by taking into account the reduction in mutation detection power that occurs when new individuals are produced from multiple cell lineages. We estimate an extremely low per generation mutation rate in both species of duckweed and note that allelic coverage at de novo mutation sites is very skewed. We also find no substantial difference in mutation rate between mutation accumulation lines propagated under benign conditions and those grown under salt stress. Finally, we discuss the implications of interpreting mutation rate estimates in vegetatively propagating organisms.

尽管在生命树中经常发生无性繁殖生物的突变率估计，但这种估计很少。在这里，我们报告了两个无性繁殖浮萍物种Lemna minor和Spirodela polyrhiza的突变率估计。考虑到当从多个细胞谱系产生新个体时发生的突变检测能力的降低，我们使用了一种改良的方法来估算突变率。我们估计两种浮萍物种的每代突变率极低，并注意到从头开始的等位基因覆盖率突变位点非常偏斜。我们还发现，在良性条件下繁殖的突变积累系与在盐胁迫下生长的突变积累系之间的突变率没有实质性差异。最后，我们讨论了在营养繁殖生物中解释突变率估算值的含义。