Preadaptation and post‐introduction evolution facilitate the invasion of Phragmites australis in North America

Cuiping

et al. 2018

Ecology and Evolution

While many introduced invasive species can increase genetic diversity through multiple introductions and/or hybridization to colonize successfully in new environments, others with low genetic diversity have to persist by alternative mechanisms such as epigenetic variation. Given that Phragmites australis is a cosmopolitan reed growing in a wide range of habitats and its invasion history, especially in North America, has been relatively well studied, it provides an ideal system for studying the role and relationship of genetic and epigenetic variation in biological invasions. We used amplified fragment length polymorphism (AFLP) and methylation‐sensitive (MS) AFLP methods to evaluate genetic and epigenetic diversity and structure in groups of the common reed across its range in the world. Evidence from analysis of molecular variance (AMOVA) based on AFLP and MS‐AFLP data supported the previous conclusion that the invasive introduced populations of P. australis in North America were from European and Mediterranean regions. In the Gulf Coast region, the introduced group harbored a high level of genetic variation relative to originating group from its native location, and it showed epigenetic diversity equal to that of the native group, if not higher, while the introduced group held lower genetic diversity than the native. In the Great Lakes region, the native group displayed very low genetic and epigenetic variation, and the introduced one showed slightly lower genetic and epigenetic diversity than the original one. Unexpectedly, AMOVA and principal component analysis did not demonstrate any epigenetic convergence between native and introduced groups before genetic convergence. Our results suggested that intertwined changes in genetic and epigenetic variation were involved in the invasion success in North America. Although our study did not provide strong evidence proving the importance of epigenetic variation prior to genetic, it implied the similar role of stable epigenetic diversity to genetic diversity in the adaptation of P. australis to local environment.

Section: Discussionmentioning

confidence: 99%

Genetic and epigenetic changes during the invasion of a cosmopolitan species (Phragmites australis)

Cuiping

et al. 2018

Ecology and Evolution

“…Guo et al. () found that photosynthesis‐ and growth‐related traits of the invasive North American populations became different from the ancestral European populations, possibly as a response to the new niche (Guo et al., ). We cannot, however, discount the possibility that the differences that we observed could also be due to introductions of different populations from Europe originating from a variety of environmental conditions.…”

Section: Discussionmentioning

confidence: 99%

“…() and Lambertini, Sorrell, Riis, Olesen, and Brix () documented genetic differentiation between the introduced North American and native European populations, and with common garden experiments, Guo et al. () revealed that post‐introduction evolution occurred with the invasion, and Pyšek et al. () identified the differences in genome size as a key trait associated with invasiveness of the common reed populations.…”

Section: Introductionmentioning

confidence: 99%

Living in two worlds: Evolutionary mechanisms act differently in the native and introduced ranges of an invasive plant

Guo

Lambertini

Pyšek

et al. 2018

Ecology and Evolution

Self Cite

Identifying the factors that influence spatial genetic structure among populations can provide insights into the evolution of invasive plants. In this study, we used the common reed (Phragmites australis), a grass native in Europe and invading North America, to examine the relative importance of geographic, environmental (represented by climate here), and human effects on population genetic structure and its changes during invasion. We collected samples of P. australis from both the invaded North American and native European ranges and used molecular markers to investigate the population genetic structure within and between ranges. We used path analysis to identify the contributions of each of the three factors—geographic, environmental, and human‐related—to the formation of spatial genetic patterns. Genetic differentiation was observed between the introduced and native populations, and their genetic structure in the native and introduced ranges was different. There were strong effects of geography and environment on the genetic structure of populations in the native range, but the human‐related factors manifested through colonization of anthropogenic habitats in the introduced range counteracted the effects of environment. The between‐range genetic differences among populations were mainly explained by the heterogeneous environment between the ranges, with the coefficient 2.6 times higher for the environment than that explained by the geographic distance. Human activities were the primary contributor to the genetic structure of the introduced populations. The significant environmental divergence between ranges and the strong contribution of human activities to the genetic structure in the introduced range suggest that invasive populations of P. australis have evolved to adapt to a different climate and to human‐made habitats in North America.

“…berlandieri haplotype (Saltonstall 2002) have been found in North America. When nuclear markers and the global phylogeography of the genus are considered, introduced haplotype M has two populations in North America: one genetically similar to the European population from which it is assumed to have descended, and one different, presumably due to postintroduction evolution that occurred in the introduced range (Lambertini et al 2012b;Guo et al 2014). The divergent population is predominantly established along the East Coast (the Atlantic Coast cluster in Lambertini et al 2006Lambertini et al , 2012b, in areas where the invasion has been extremely aggressive and the native P. australis ssp.…”

Section: Introductionmentioning

confidence: 99%

Heteroplasmy due to chloroplast paternal leakage: another insight into Phragmites haplotypic diversity in North America

Lambertini

2016

Biol Invasions

Self Cite

Chloroplasts contain several copies of their DNA, and intra-individual haplotypic variation (heteroplasmy) is common in plants, but unexplored in the cosmopolitan genus Phragmites. The aims of this study were to assess if heteroplasmy due to paternal leakage of the chloroplast occurs in Phragmites and which new insights into the evolutionary history of Phragmites australis in North America can be identified from the heteroplasmic variation. Eight nonnative P. australis haplotypes occur in North America and can interbreed with P. australis ssp. americanus and P. australis var. berlandieri, creating opportunities for biparental inheritance of distinctive haplotypes. The polymorphism in the trnT-trnL sequence length revealed seventeen cases of heteroplasmy worldwide, in contact zones of distantly related haplotypes and in known hybrid populations, nine of which occurred in North America. In America, the cloned sequences, combined with nuclear markers, identified recombined haplotypes between native P. australis ssp. americanus and invasive P. australis haplotype M, and between the species P. mauritianus and P. australis, due to chloroplast paternal leakage. The occurrence of heteroplasmy and recombined haplotypes suggest a local origin for some of the rare non-native haplotypes occurring in North America, and plastid leakage events in the evolutionary histories of P. australis ssp. americanus and P. australis var. berlandieri.