The immediate effects of polyploidization ofSpirodela polyrhizachange in a strain-specific way along environmental gradients

Abstract

The immediate effects of plant polyploidization are well characterized and it is generally accepted that these morphological, physiological, developmental, and phenological changes contribute to polyploid establishment. Studies on the environmental dependence of the immediate effects of whole-genome duplication (WGD) are, however, scarce but suggest that these immediate effects are altered by stressful conditions. As polyploid establishment seems to be associated with environmental disturbance, the relationship between ploidy-induced phenotypical changes and environmental conditions is highly relevant. Here, we use a common garden experiment on the greater duckweed Spirodela polyrhiza to test whether the immediate effects of WGD can facilitate the establishment of tetraploid duckweed along gradients of two environmental stressors. Because successful polyploid establishment often depends on recurrent polyploidization events, we include four genetically diverse strains and assess whether these immediate effects are strain-specific. We find evidence that WGD can indeed confer a fitness advantage under stressful conditions and that the environment affects ploidy-induced changes in fitness and trait reaction norms in a strain-specific way.

Dynamics of mixed-ploidy populations under demographic and environmental stochasticities

“…Recent work suggests that, in some instances, cytotypes can perceive the same environmental state differently (Bafort et al 2023). Hence, instead of modeling explicit directional competition among cytotypes and their community members, our study allows divergence in niche among cytotypes to be driven by the environment.…”

“…Similarly, in low environmental variance, we identified shifts in competitive ability among model replicates. In relation to environmental variation, the growth rate and carrying capacity of tetraploid Spirodela polyrhiza (Araceae) were lower than those of cooccurring diploids (Anneberg et al 2023); however, a tetraploid fitness advantage was identified in saline environments (Bafort et al, 2023). Despite the competitive disadvantage of S. polyrhiza tetraploids compared to diploids in most treatments, tetraploids were found to invest more than their diploid progenitors into future growth through dormant propagules (Anneberg et al, 2023) environments.…”

“…Despite common adaptations found in multiple systems, the mechanisms driving these responses are complex and difficult to model. For example, the interaction among ploidy, environment, and genotype has been found to influence cytotype-specific competitive advantage (Bafort et al 2023;Van Drunen and Husband 2018).…”

“…Similar adaptations have been confirmed in neopolyploids. For example, tetraploids have been identified to persist in high-salinity(Bafort et al 2023;Chao et al 2013; Scarrow et al 2022;Thomas et al 2022;Xu et al 2021) and water-limited(Laport et al 2017;Yang et al 2014)…”

Neopolyploidy increases stress tolerance and reduces fitness plasticity across multiple urban pollutants: support for the ‘general purpose’ genotype hypothesis

“…The most appropriate fitness comparison is to be made at the population level, where diploid and polyploid growth both within generations and reproduction among generations contribute to population fitness (e.g., Selmecki et al, 2015;Anneberg et al, 2023). Recurrent formation of polyploids from genetically different diploids is a common phenomenon in nature (Soltis & Soltis, 1999;Kolář et al, 2017) and could lead to variation in stress tolerance even when polyploidy involves one parental genome (autopolyploidy) rather than two genomes (allopolyploidy) (e.g., Wei et al, 2019;Bafort et al, 2023;Mattingly & Hovick, 2023). This variation in stress tolerance may ultimately determine the probability of polyploid establishment under novel or stressful conditions (Soltis & Soltis, 1999;Van Drunen & Johnson, 2022).…”