Polyploid evolution: The ultimate way to grasp the nettle

Abstract

Polyploidy is one of the major forces of plant evolution and widespread mixed-ploidy species offer an opportunity to evaluate its significance. We therefore selected the cosmopolitan species Urtica dioica (stinging nettle), examined its cytogeography and pattern of absolute genome size, and assessed correlations with bioclimatic and ecogeographic data (latitude, longitude, elevation). We evaluated variation in ploidy level using an extensive dataset of 7012 samples from 1317 populations covering most of the species’ distribution area. The widespread tetraploid cytotype (87%) was strongly prevalent over diploids (13%). A subsequent analysis of absolute genome size proved a uniform Cx-value of core U. dioica (except for U. d . subsp. cypria ) whereas other closely related species, namely U. bianorii , U. kioviensis and U. simensis , differed significantly. We detected a positive correlation between relative genome size and longitude and latitude in the complete dataset of European populations and a positive correlation between relative genome size and longitude in a reduced dataset of diploid accessions (the complete dataset of diploids excluding U. d . subsp. kurdistanica ). In addition, our data indicate an affinity of most diploids to natural and near-natural habitats and that the tetraploid cytotype and a small part of diploids (population from the Po river basin in northern Italy) tend to inhabit synanthropic sites. To sum up, the pattern of ploidy variation revealed by our study is in many aspects unique to the stinging nettle, being most likely first of all driven by the greater ecological plasticity and invasiveness of the tetraploid cytotype.

Intricate Distribution Patterns of Six Cytotypes of Allium oleraceum at a Continental Scale: Niche Expansion and Innovation Followed by Niche Contraction With Increasing Ploidy Level

“…In contrast, the niche of polyploid A. oleraceum also comprises more mesic (colder and moister) climatic conditions ( Figures 1 – 3 ) and a wide spectrum of habitat types, including fertile weedy habitats ( Figure 4 ). The stronger synanthropic affinity of polyploids, in contrast to their diploid congeners, was recently found in several polyploid complexes (Zozomová-Lihová et al, 2014 ; Chung et al, 2015 ; Němečková et al, 2019 ; Rejlová et al, 2019 ). Exact niche comparison between polyploid A. oleraceum and its diploid progenitors is needed, as soon as molecular analyses reveal the diploid progenitors of A. oleraceum .…”

Whole genome duplication increases ecological niche breadth of the perennial herb Urtica dioica

“…We selected southern Moravia (Czech Republic) as it is a typical central-European alluvial landscape with a high diversity and fine-scale heterogeneity of different types of vegetation. Both diploid and tetraploid cytotypes of Urtica dioica occur in this north-western part of the Pannonian biogeographical region (Rejlová et al 2019). Southern Moravia is a region of thermophilous flora, with mean annual temperatures of 9-10 °C and annual precipitation between 450-550 mm (Tolasz et al 2007).…”

“…The pattern of conspecific diploids and autopolyploids (tetraploids) with contrasting geographical ranges is perfectly exemplified by Urtica dioica L., a perennial herbaceous plant native of the temperate zone of Eurasia and northern Africa. In Europe, diploids have a disjunct distribution and likely to occur in relict, less human-affected habitats such as alluvial forests, willow galleries on river banks, ravine forests, wet lowland alluvial meadows and reed beds, whereas widely distributed weedy tetraploids seem to occur in a wide range of habitats, especially in those with an increased degree of human influence (Henning et al 2014, Grosse-Veldmann & Weigend 2015, Grosse-Veldmann et al 2016, Rejlová et al 2019. In Europe, tetraploids are mostly referred to as Urtica dioica subsp.…”

Биологические ресурсы Urtica dioica L.: направления исследований и перспективы использования

“…Установлено, что в Европе преимущественно распространен тетраплоидный цитотип (87 %), а диплоидных форм около 13 %. Большинство диплоидных форм приурочены к естественным и почти естественным местообитаниям, а тетраплоидные формы имеют тенденцию заселять синантропные участки [Rejlová et al, 2019].…”