Invasion success and genetic diversity of introduced populations of guppies Poecilia reticulata in Australia

AbstractOne of the fundamental questions in invasion biology is to understand the genetic mechanisms behind success or failure during the establishment of a species. However, major limitations to understanding are usually a lack of spatiotemporal population data and information on the populations’ colonisation history. In a large-scale, detailed study on the bush-cricket Metrioptera roeselii 70 groups of founders were introduced in areas outside the species’ distribution range. We examined how (1) the number of founders (2–32 individuals), (2) the time since establishment (7 or 15 years after introduction) and (3) possible gene flow affected establishment success and temporal genetic changes of the introduced populations. We found higher establishment success in introductions with larger propagule sizes but genetic diversity indices were only partly correlated to propagule size. As expected, introduced populations were more similar to their founder population the larger the propagule size was. However, even if apparent at first, most of the differentiation in the small propagule introductions disappeared over time. Surprisingly, genetic variability was regained to a level comparable to the large and outbreeding founder population only 15 generations after severe demographic bottlenecks. We suggest that the establishment of these populations could be a result of several mechanisms acting in synergy. Here, rapid increase in genetic diversity of few introductions could potentially be attributed to limited gene flow from adjacent populations, behavioural adaptations and/or even increased mutation rate. We present unique insights into genetic processes that point towards traits that are important for understanding species’ invasiveness.

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Loss of Genetic Diversity with Captive Breeding and Re-Introduction: A Case Study on Pateke/Brown Teal (Anas chlorotis)

10.26686/wgtn.16992715 ◽

2021 ◽

Author(s):

◽

Gemma Bowker-Wright

Keyword(s):

Genetic Diversity ◽

Mitochondrial Dna ◽

Captive Breeding ◽

Barrier Island ◽

Breeding Population ◽

Island Population ◽

Wildlife Sanctuary ◽

Management Options ◽

Introduced Populations ◽

Loss Of Genetic Diversity

<p>Pateke/brown teal (Anas chlorotis) have experienced a severe population crash leaving only two remnant wild populations (at Great Barrier Island and Mimiwhangata, Northland). Recovery attempts over the last 35 years have focused on an intensive captive breeding programme which breeds pateke, sourced almost exclusively from Great Barrier Island, for release to establish re-introduced populations in areas occupied in the past. While this important conservation measure may have increased pateke numbers, it was unclear how much of their genetic diversity was being retained. The goal of this study was to determine current levels of genetic variation in the remnant, captive and re-introduced pateke populations using two types of molecular marker, mitochondrial DNA (mtDNA) and microsatellite DNA. Feathers were collected from pateke at Great Barrier Island, Mimiwhangata, the captive breeding population and four re-introduced populations (at Moehau, Karori Wildlife Sanctuary, Tiritiri Matangi Island and Mana Island). DNA was extracted from the base of the feathers, the mitochondrial DNA control region was sequenced, and DNA microsatellite markers were used to genotype individuals. The Great Barrier Island population was found to have only two haplotypes, one in very high abundance which may indicate that historically this population was very small. The captive breeding population and all four re-introduced populations were found to contain only the abundant Great Barrier Island haplotype as the vast majority of captive founders were sourced from this location. In contrast, the Mimiwhangata population contained genetic diversity and 11 haplotypes were found, including the Great Barrier Island haplotype which may have been introduced by captive-bred releases which occurred until the early 1990s. From the microsatellite results, a loss of genetic diversity (measured as average alleles per locus, heterozygosity and allelic richness) was found from Great Barrier Island to captivity and from captivity to re-introduction. Overall genetic diversity within the re-introduced populations (particularly the smaller re-introduced populations at Karori Wildlife Sanctuary, Tiritiri Matangi Island and Mana Island) was much reduced compared with the remnant populations, most probably as a result of small release numbers and small population size. Such loss of genetic diversity could render the re-introduced populations more susceptible to inbreeding depression in the future. Suggested future genetic management options are included which aim for a broader representation of genetic diversity in the pateke captive breeding and release programme.</p>

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Genetic diversity in Undaria pinnatifida (Laminariales, Phaeophyceae) deduced from mitochondria genes – origins and succession of introduced populations

Phycologia ◽

10.2216/05-66.1 ◽

2006 ◽

Vol 45 (6) ◽

pp. 687-695 ◽

Cited By ~ 66

Author(s):

Shinya Uwai ◽

Wendy Nelson ◽

Kate Neill ◽

Wei Ding Wang ◽

Luis E. Aguilar-Rosas ◽

...

Keyword(s):

Genetic Diversity ◽

Undaria Pinnatifida ◽

Introduced Populations

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Epigenetic Potential in Native and Introduced Populations of House Sparrows (Passer domesticus)

Integrative and Comparative Biology ◽

10.1093/icb/icaa060 ◽

2020 ◽

Vol 60 (6) ◽

pp. 1458-1468 ◽

Cited By ~ 1

Author(s):

Haley E Hanson ◽

Bilal Koussayer ◽

Holly J Kilvitis ◽

Aaron W Schrey ◽

J Dylan Maddox ◽

...

Keyword(s):

Genetic Diversity ◽

Phenotypic Plasticity ◽

Statistical Power ◽

Passer Domesticus ◽

House Sparrows ◽

Cpg Sites ◽

Introduced Populations ◽

Introduced Birds ◽

The Individual ◽

Native Birds

Synopsis Epigenetic potential, defined as the capacity for epigenetically-mediated phenotypic plasticity, may play an important role during range expansions. During range expansions, populations may encounter relatively novel challenges while experiencing lower genetic diversity. Phenotypic plasticity via epigenetic potential might be selectively advantageous at the time of initial introduction or during spread into new areas, enabling introduced organisms to cope rapidly with novel challenges. Here, we asked whether one form of epigenetic potential (i.e., the abundance of CpG sites) in three microbial surveillance genes: Toll-like receptors (TLRs) 1B (TLR1B), 2A (TLR2A), and 4 (TLR4) varied between native and introduced house sparrows (Passer domesticus). Using an opportunistic approach based on samples collected from sparrow populations around the world, we found that introduced birds had more CpG sites in TLR2A and TLR4, but not TLR1B, than native ones. Introduced birds also lost more CpG sites in TLR1B, gained more CpG sites in TLR2A, and lost fewer CpG sites in TLR4 compared to native birds. These results were not driven by differences in genetic diversity or population genetic structure, and many CpG sites fell within predicted transcription factor binding sites (TFBS), with losses and gains of CpG sites altering predicted TFBS. Although we lacked statistical power to conduct the most rigorous possible analyses, these results suggest that epigenetic potential may play a role in house sparrow range expansions, but additional work will be critical to elucidating how epigenetic potential affects gene expression and hence phenotypic plasticity at the individual, population, and species levels.

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Phylogeography of the widespread marine invaderMicrocosmus squamiger(Ascidiacea) reveals high genetic diversity of introduced populations and non-independent colonizations

Diversity and Distributions ◽

10.1111/j.1472-4642.2008.00485.x ◽

2008 ◽

Vol 14 (5) ◽

pp. 818-828 ◽

Cited By ~ 52

Author(s):

Marc Rius ◽

Marta Pascual ◽

Xavier Turon

Keyword(s):

Genetic Diversity ◽

High Genetic Diversity ◽

Introduced Populations

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DNA-Based Marker Systems to Determine Genetic Diversity of Weedy Species and Their Application to Biocontrol

Weed Science ◽

10.1017/s0043174500081546 ◽

1995 ◽

Vol 43 (3) ◽

pp. 504-513 ◽

Cited By ~ 54

Author(s):

Scott J. Nissen ◽

Robert A. Masters ◽

Donald J. Lee ◽

Martha L. Rowe

Keyword(s):

Genetic Diversity ◽

Biological Control ◽

Weed Control ◽

Random Amplified Polymorphic Dna ◽

Biological Weed Control ◽

Multiple Introductions ◽

Introduced Populations ◽

Length Polymorphisms ◽

Geographic Origins ◽

Weedy Species

DNA-based molecular markers may provide information about introduced weedy species that would be useful in biological weed control efforts. Chloroplast DNA restriction fragment length polymorphisms (cpDNA RFLP) and random amplified polymorphic DNA (RAPD) analysis are two DNA-based marker techniques that can provide estimates of genetic variation in native and introduced populations of weedy species. Profiles provided by these techniques could furnish the necessary information to determine the geographic origins of introduced species and provide evidence for multiple introductions. Although DNA-based markers would not necessarily identify the genetic basis for host-pest compatibility, they would enable identification of specific host genotypes. Current criteria for selecting a weedy species as a target for biological control are primarily political and economic. The importance of genetic diversity and population structure in determining the vulnerability of plant populations to insects or diseases has not been fully appreciated. Estimates of genetic diversity based on DNA marker analysis could be used as one criteria for determining which plants are targeted for biological control. The success of biological weed control efforts has been limited by the high levels of genetic diversity occurring in target weed specks and the lack of biocontrol agent and target weed compatibilities. DNA-based markers may be used to increase our understanding of these factors and contribute to the success of biological weed control by helping to target the most vulnerable species and provide more realistic expectations of the potential for success given available resources.

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Root flavonoids are related to enhanced AMF colonization of an invasive tree

AoB Plants ◽

10.1093/aobpla/plaa002 ◽

2020 ◽

Vol 12 (1) ◽

Cited By ~ 3

Author(s):

Yingchun Pei ◽

Evan Siemann ◽

Baoliang Tian ◽

Jianqing Ding

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Invasive Plants ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Plant Invasions ◽

Invasion Success ◽

Chemical Mechanism ◽

Introduced Populations ◽

Native Populations ◽

Invasive Tree

Abstract Arbuscular mycorrhizal fungi (AMF) are important mutualistic microbes in soil, which have capacity to form mutualistic associations with most land plants. Arbuscular mycorrhizal fungi play an important role in plant invasions and their interactions with invasive plants have received increasing attention. However, the chemical mechanisms underlying the interactions of AMF and invasive plants are still poorly understood. In this study we aim to test whether root secondary chemicals are related to enhanced AMF colonization and rapid growth in an invasive tree. We conducted a common garden experiment in China with Chinese tallow tree (Triadica sebifera) to examine the relationships among AMF colonization and secondary metabolites in roots of plants from introduced (USA) and native (China) populations. We found that AMF colonization rate was higher in introduced populations compared to native populations. Roots of plants from introduced populations had lower levels of phenolics and tannins, but higher levels of flavonoids than those of plants from native populations. Flavonoids were positively correlated with AMF colonization, and this relationship was especially strong for introduced populations. Besides, AMF colonization was positively correlated with plant biomass suggesting that higher root flavonoids and AMF colonization may impact plant performance. This suggests that higher root flavonoids in plants from introduced populations may promote AMF spore germination and/or attract hyphae to their roots, which may subsequently increase plant growth. Overall, our results support a scenario in which invasive plants enhance their AMF association and invasion success via genetic changes in their root flavonoid metabolism. These findings advance our understanding of the mechanisms underlying plant invasion success and the evolutionary interactions between plants and AMF. Understanding such mechanisms of invasive plant success is critical for predicting and managing plant invasions in addition to providing important insights into the chemical mechanism of AMF–plant interactions.

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