Low genetic diversity despite multiple introductions of the invasive plant species Impatiens glandulifera in Europe

Abstract

BackgroundInvasive species can be a major threat to native biodiversity and the number of invasive plant species is increasing across the globe. Population genetic studies of invasive species can provide key insights into their invasion history and ensuing evolution, but also for their control. Here we genetically characterise populations of Impatiens glandulifera, an invasive plant in Europe that can have a major impact on native plant communities. We compared populations from the species’ native range in Kashmir, India, to those in its invaded range, along a latitudinal gradient in Europe. For comparison, the results from 39 other studies of genetic diversity in invasive species were collated.ResultsOur results suggest that I. glandulifera was established in the wild in Europe at least twice, from an area outside of our Kashmir study area. Our results further revealed that the genetic diversity in invasive populations of I. glandulifera is unusually low compared to native populations, in particular when compared to other invasive species. Genetic drift rather than mutation seems to have played a role in differentiating populations in Europe. We find evidence of limitations to local gene flow after introduction to Europe, but somewhat less restrictions in the native range. I. glandulifera populations with significant inbreeding were only found in the species’ native range and invasive species in general showed no increase in inbreeding upon leaving their native ranges. In Europe we detect cases of migration between distantly located populations. Human activities therefore seem to, at least partially, have facilitated not only introductions, but also further spread of I. glandulifera across Europe.ConclusionsAlthough multiple introductions will facilitate the retention of genetic diversity in invasive ranges, widespread invasive species can remain genetically relatively invariant also after multiple introductions. Phenotypic plasticity may therefore be an important component of the successful spread of Impatiens glandulifera across Europe.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-015-0242-8) contains supplementary material, which is available to authorized users.

Floods affect the abundance of invasive Impatiens glandulifera and its spread from river corridors

“…The species is further favoured by a wide phenotypic plasticity (Kurtto, 1996;Sk alov a et al, 2012; but see Elst et al, 2016) and by the lack of diseases, pests and herbivores in the invaded range (Beerling & Perrins, 1993;Schmitz, 1991; but see Tanner et al, 2015). In the past, the plant was propagated and distributed by gardeners and beekeepers, and migration among distantly located populations has been inferred from reports about seed exchange (Kurtto, 1996) and using molecular techniques (Hagenblad et al, 2015). The first occurrence outside cultivation in the Czech Republic was recorded in 1896 near the town of Litom e rice, and in 1900, it was first found at a riparian site on the bank of the river Svitava (Py sek & Prach, 1995b).…”

The invasive bighead goby Ponticola kessleri displays large‐scale genetic similarities and small‐scale genetic differentiation in relation to shipping patterns

“…Invasive species have been found to harbour significant levels of standing variation in the invasive range (Kolbe et al 2004(Kolbe et al , 2007(Kolbe et al , 2008Stepien & Tumeo 2006;Hochkirch & Damerau 2009). In some instances, invasive populations are genetically not diverse or even clonal, but nonetheless highly successful (Dlugosch & Parker 2008;Zhang et al 2010;Carvalho et al 2014;Lobos et al 2014;Pigneur et al 2014;Hagenblad et al 2015;Ray et al 2015). Dependent on the species specific situation, these unexpected observations have been explained by a variety of biological and/or evolutionary genetics mechanisms: large numbers of founding propagules (Simberloff 2009), parallel introduction events from diverse source populations (Durka et al 2005;Henshaw et al 2005;Brown & Stepien 2009;Zalewski et al 2010), clonal reproduction strategies (Chapman et al 2004), introgression events (Choler et al 2004;Suehs et al 2004), fast drift at the wave front of expanding populations (Edmonds et al 2004;Miller 2010), fast adaptation and selection processes in the very early establishment phases (Phillips et al 2006;Kelehear et al 2012) or intraspecific admixture (Kolbe et al 2008).…”

Invasion history of Cardamine hirsuta in Japan inferred from genetic analyses of herbarium specimens and current populations

“…However, it may not facilitate the invasion of species with low outcrossing rates, such as autogamous plants and clonal plants, because crosses among individuals from different populations, as well as within the same population, are rare. Although infrequent outcrossing events have been shown to play an important role in betweenpopulation gene flow for selfing and clonal species (Nordborg et al 2005;Grimsby and Kesseli 2010), many invasive species with low outcrossing rates show low genetic diversity within a population, and low heterozygosity even if multiple introductions have occurred (Zhang et al 2010;Hagenblad et al 2015). Rather, single populations may have a single genotype as a result of stochastic founder events, or competition among individuals with different genotypes, resulting in low genetic diversity within the population (Amsellem et al 2000;Mergeay et al 2006;Le Roux et al 2007).…”

“…Here, we focus on genetic diversity among localities brought by multiple introductions and the possibility that such genetic diversity may contribute to invasion in a non-native range. Various invasive species had a low genetic diversity distribution at the local level but high diversity at a wider range (Rosenthal et al 2008;Matesanz et al 2014;Hagenblad et al 2015). This genotype might not be able to extend its distribution due to certain ecological factors, including limited adaptation ability.…”