Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex

Abstract

Summary Niche evolution in plant polyploids remains controversial and evidence for alternative patterns has been reported. Using the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×) as a model, we aimed to integrate three scenarios – competitive exclusion, recurrent origins of cytotypes and niche filling – into a single framework of polyploid niche evolution. We hypothesized that high polyploids would tend to evolve towards extreme niches when low ploidy cytotypes have nearly filled the niche space. We used several ecoinformatics and phylogenetic comparative analyses to quantify differences in the ecological niche of each cytotype and to evaluate alternative models of niche evolution. Each cytotype in this complex occupied a distinct ecological niche. The distributions were mainly constrained by soil characteristics, temperature and drought stress imposed by the Mediterranean climate. Tetraploids had the highest niche breadth and overlap due to their multiple origins, whereas the higher ploidy cytotypes were found in different, restricted, nonoverlapping niches. Niche evolution analyses suggested a scenario with one niche optimum for each ploidy, including the two independent tetraploid lineages. Our results suggest that the fate of nascent polyploids could not be predicted without accounting for phylogenetic relatedness, recurrent origins or the niche occupied by ancestors.

Cytotype Distribution and Chloroplast Phylogeography of Actinidia Chinensis Complex

“…However, in the LGM period, these species will move down and get more suitable habitats with the decrease of temperature, which shows the expansion of the population, and even the reunion of groups at different mountain ends of the lowland. Besides, polyploidization promoted species to obtain a broader niche, which has been veri ed in previous studies [59][60][61][62]. In this study, the ecological niche differentiation between var.…”

Different Patterns of Ecological Divergence Between Two Tetraploids and Their Diploid Counterpart in a Parapatric Linear Coastal Distribution Polyploid Complex

“…Niche modeling (e.g., Ecological Niche Modeling; Warren et al, 2008Warren et al, , 2010 and multivariate analyses of predictor variables (Broennimann et al, 2012) are useful tools for examining relationships between large-scale cytotype distributions and environmental tolerances. These methods take advantage of global climate and habitat databases to relate the geographic distributions of diploid and polyploid populations to spatial environmental data, supporting the creation of predictions about niche shifts or niche conservation associated with whole genome duplication (e.g., Glennon et al, 2012;Godsoe et al, 2013;Thompson et al, 2014;Visger et al, 2016;Muñoz-Pajares et al, 2018;López-Jurado et al, 2019;Molina-Henao and Hopkins, 2019). Such approaches are powerful in scope and useful for generating hypotheses that can be further tested using manipulative experiments (Glennon et al, 2014;Marchant et al, 2016), such as reciprocal transplants (e.g., C. angustifolium, Martin and Husband, 2013).…”

Climate change influences on the potential distribution of Dianthus polylepis Bien. ex Boiss. (Caryophyllaceae), an endemic species in the Irano-Turanian region

“…In particular, in our analyses, mean diurnal temperature range, iso-thermality, minimum temperature of coldest quarter, and annual precipitation, were factors of importance in delimiting the niche of this species. Although fieldbased information of this sort is not available for D. polylepis, a recent study by López-Jurado et al [30] indicated that the distribution of another Dianthus species, the D. broteri complex, in the Mediterranean region is constrained by environmental variables related to temperature and drought stress (potential evapotranspiration in the driest and warmest quarters), along with edaphic properties. Distributions of Dianthus species in the D. pungens group depend on elevation and temperature [27].…”

“…polylepis in the Irano-Turanian region under current and future climate conditions. Dianthus polylepis is restricted to montane areas, and the species’ distribution appears to have been molded by a combination of access by dispersal (i.e., it has not been able to colonize apparently suitable areas in montane areas that are relatively close by), past speciation history [ 67 ], and environmental conditions in terms of temperature and precipitation [ 30 , 68 ]. In particular, in our analyses, mean diurnal temperature range, iso-thermality, minimum temperature of coldest quarter, and annual precipitation, were factors of importance in delimiting the niche of this species.…”

“…Over half of its species occur in small, geographically restricted ranges [ 27 , 28 ]. Previous studies have highlighted that climatic preferences have played prominent roles in the evolution and diversification of Dianthus [ 27 – 30 ]. In addition, most Dianthus species in the Irano-Turanian region live in rocky mountain habitats that may be affected severely by changing environmental conditions, land-use changes, and human activities.…”