scholarly journals Population genetic structure and connectivity of a riparian selfing herb Caulokaempferia coenobialis at a fine-scale geographic level in subtropical monsoon forest

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qiong Fu ◽  
Jie Deng ◽  
Min Chen ◽  
Yan Zhong ◽  
Guo-Hui Lu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Complex Mixture ◽  
Conservation Strategies ◽  
Riparian Plants ◽  
Local Populations ◽  
Genetic Diversity And Structure ◽  
Monsoon Forest

Abstract Background Rivers and streams facilitate movement of individuals and their genes across the landscape and are generally recognized as dispersal corridors for riparian plants. Nevertheless, some authors have reported directly contrasting results, which may be attributed to a complex mixture of factors, such as the mating system and dispersal mechanisms of propagules (seed and pollen), that make it difficult to predict the genetic diversity and population structure of riparian species. Here, we investigated a riparian self-fertilizing herb Caulokaempferia coenobialis, which does not use anemochory or zoochory for seed dispersal; such studies could contribute to an improved understanding of the effect of rivers or streams on population genetic diversity and structure in riparian plants. Using polymorphic ISSR and cpDNA loci, we studied the effect at a microgeographic scale of different stream systems (a linear stream, a dendritic stream, and complex transverse hydrological system) in subtropical monsoon forest on the genetic structure and connectivity of C. coenobialis populations across Dinghu Mountain (DH) and Nankun Mountain (NK). Results The results indicate that the most recent haplotypes (DH: H7, H8; NK: h6, h7, h11, h12) are not shared among local populations of C. coenobialis within each stream system. Furthermore, downstream local populations do not accumulate genetic diversity, whether in the linear streamside local populations across DH (H: 0.091 vs 0.136) or the dendritic streamside local populations across NK (H: 0.079 vs 0.112, 0.110). Our results show that the connectivity of local C. coenobialis populations across DH and NK can be attributed to historical gene flows, resulting in a lack of spatial genetic structure, despite self-fertilization. Selfing C. coenobialis can maintain high genetic diversity (H = 0.251; I = 0.382) through genetic differentiation (GST = 0.5915; FST = 0.663), which is intensified by local adaptation and neutral mutation and/or genetic drift in local populations at a microgeographic scale. Conclusion We suggest that streams are not acting as corridors for dispersal of C. coenobialis, and conservation strategies for maintaining genetic diversity of selfing species should be focused on the protection of all habitat types, especially isolated fragments in ecosystem processes.

scholarly journals Oceanographic features and limited dispersal shape the population genetic structure of the vase sponge Ircinia campana in the Greater Caribbean

Heredity ◽  
2020 ◽  
Vol 126 (1) ◽  
pp. 63-76
Author(s):  
Sarah M. Griffiths ◽  
Mark J. Butler ◽  
Donald C. Behringer ◽  
Thierry Pérez ◽  
Richard F. Preziosi
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Larval Dispersal ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Florida Keys ◽  
The United States ◽  
Limited Dispersal ◽  
Mass Mortalities

AbstractUnderstanding population genetic structure can help us to infer dispersal patterns, predict population resilience and design effective management strategies. For sessile species with limited dispersal, this is especially pertinent because genetic diversity and connectivity are key aspects of their resilience to environmental stressors. Here, we describe the population structure of Ircinia campana, a common Caribbean sponge subject to mass mortalities and disease. Microsatellites were used to genotype 440 individuals from 19 sites throughout the Greater Caribbean. We found strong genetic structure across the region, and significant isolation by distance across the Lesser Antilles, highlighting the influence of limited larval dispersal. We also observed spatial genetic structure patterns congruent with oceanography. This includes evidence of connectivity between sponges in the Florida Keys and the southeast coast of the United States (>700 km away) where the oceanographic environment is dominated by the strong Florida Current. Conversely, the population in southern Belize was strongly differentiated from all other sites, consistent with the presence of dispersal-limiting oceanographic features, including the Gulf of Honduras gyre. At smaller spatial scales (<100 km), sites showed heterogeneous patterns of low-level but significant genetic differentiation (chaotic genetic patchiness), indicative of temporal variability in recruitment or local selective pressures. Genetic diversity was similar across sites, but there was evidence of a genetic bottleneck at one site in Florida where past mass mortalities have occurred. These findings underscore the relationship between regional oceanography and weak larval dispersal in explaining population genetic patterns, and could inform conservation management of the species.

Fine-scale structure within a Trillium maculatum (Liliaceae) population

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Alana N. Walker ◽  
Stephanie A. Foré ◽  
Beverly Collins
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Vegetative Reproduction ◽  
Flowering Plants ◽  
Life History Stages ◽  
Genetic Diversity And Structure ◽  
Random Expectation ◽  
Perennial Herbs

In long-lived ant-dispersed perennial herbs of mesic forests, interactions among fruiting plants, seed dispersal, and plant mortality over life-history stages can create demographic and genetic structure. We investigated whether there was nonrandom variation in the distributions of individuals and in genetic diversity within and among life-history stages of the forest herb Trillium maculatum Raf. (Liliaceae). In 2002 and 2004, all T. maculatum plants in a 5 m × 5 m plot (1572 and 1379 individuals, respectively) were mapped and classified as seedling, one-leaf, three-leaf nonflowering, or flowering. Spatial distributions of plants within and across life-history stages were tested against random expectation. Allozyme analysis of 262 individuals from three life-history stages was used to assess genetic diversity and structure in 2004. The number of seedlings and the proportion of one-leaf plants differed between years, but the proportions of three-leaf nonflowering and flowering plants remained the same. There was little evidence of vegetative reproduction, but heterozygosity was low and there was evidence of inbreeding. Seedlings were clumped around flowering plants at distances up to 50 cm and one-leaf plants were clumped at distances up to 100 cm. There were no apparent genetic differences among life-history stages, nor any apparent spatial genetic structure among all sampled individuals. These results, like those of other demographic and allozyme studies of Trillium species, can be explained by restricted dispersal and random mortality.

scholarly journals The genetic structure of the European black pine (Pinus nigra Arnold) is shaped by its recent Holocene demographic history

2019 ◽  
Author(s):  
Guia Giovannelli ◽  
Caroline Scotti-Saintagne ◽  
Ivan Scotti ◽  
Anne Roig ◽  
Ilaria Spanu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Demographic History ◽  
Pinus Nigra ◽  
Forest Tree ◽  
Black Pine ◽  
Genetic Lineages ◽  
European Black Pine

AbstractFragmentation acting over geological times confers wide, biogeographical scale, genetic diversity patterns to species, through demographic and natural selection processes. To test the effects of historical fragmentation on the genetic diversity and differentiation of a major European forest tree and to resolve its demographic history, we describe and model its spatial genetic structure and gene genealogy. We then test which Pleistocene event, whether recent or ancient, could explain its widespread but patchy geographic distribution using population genetic data, environmental data and realistic demographic timed scenarios.The taxon of interest is a conifer forest tree, Pinus nigra (Arnold), the European black pine, whose populations are located in the mountains of southern Europe and North Africa, most frequently at mid-elevation. We used a set of different genetic markers, both neutral and potentially adaptive, and either bi-parentally or paternally inherited, and we sampled natural populations across the entire range of the species. We analysed the data using frequentist population genetic methods as well as Bayesian inference methods to calibrate realistic, demographic timed scenarios.Species with geographically fragmented distribution areas are expected to display strong among-population genetic differentiation and low within-population genetic diversity. Contrary to these expectations, we show that the current diversity of Pinus nigra and its weak genetic spatial structure are best explained as resulting from late Pleistocene or early Holocene fragmentation of one ancestral population into seven genetic lineages, which we found to be the main biogeographical contributors of the natural black pine forests of today. Gene flow among the different lineages is strong across forests and many current populations are admixed between lineages. We propose to modify the currently accepted international nomenclature made of five subspecies and name these seven lineages using regionally accepted subspecies-level names.HighlightsThe European black pine, Pinus nigra (Arnold), has a weak spatial genetic structure.Gene flow among populations is frequent and populations are often of admixed origin.Current genealogies result from recent, late Pleistocene or Holocene events.Seven modern genetic lineages emerged from divergence and demographic contractions.These seven lineages warrant a revision of subspecies taxonomic nomenclature.

scholarly journals High genetic diversity and strong genetic structure of Strongyllodes variegatus (Coleoptera: Nitidulidae) demonstrate the genetic mechanism of its distribution in oilseed rape production areas in China

2020 ◽  
Author(s):  
HaiXia Zhan ◽  
ZhongPing Hao ◽  
JingJiang Zhou ◽  
Rui Tang ◽  
LiNi Zhu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Gene Flow ◽  
Genetic Structure ◽  
Oilseed Rape ◽  
Population Genetic ◽  
Distribution Analysis ◽  
Geographical Regions ◽  
Genetic Diversity And Structure ◽  
Production Areas

Abstract Background : Strongyllodes variegatus (Fairmaire) is a major insect pest of oilseed rape in China. Despite its economic importance, the population genetics of this pest contributing to the development of suitable management and control strategies is poorly known. To understand the population genetics and assess the geographical patterns and genetic structure of S. variegates in China. Using mitochondrial DNA cytochrome c oxidase subunit I and cytochrome b region sequences as genetic markers, we analyzed population genetic diversity and structure from 437 individuals collected in 15 S. variegates populations located in different oilseed rape production areas in China. In addition, we estimated the demographic history using neutrality test and mismatch distribution analysis. Results : The high level of genetic diversity was detected among the mtDNA region sequences of S. variegates . The population structure analysis strongly suggested that three genetic and geographical regions occur with limited gene flow. The Mantel test showed that the genetic distance was greatly influenced by geographical distance. The demographic analyses showed that S. variegates experienced population fluctuation during the Pleistocene, which was likely to be related to the climatic changes. Conclusion : Overall, these results demonstrated that the strong population genetic structure of this beetle may attribute to the geographical barriers and subsequently adapt to the regional ecological conditions for the distribution of S. variegates in China. Keywords : Gene flow, Genetic differentiation, Haplotype, Oilseed rape, Population genetic pattern, Strongyllodes variegates

scholarly journals Genetic structure of annual ryegrass (Lolium multiflorum) populations estimated by RAPD

2004 ◽  
Vol 61 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Eduardo Alano Vieira ◽  
Caroline Marques Castro ◽  
Antônio Costa de Oliveira ◽  
Fernando Irajá Félix de Carvalho ◽  
Paulo Dejalma Zimmer ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Diversity Index ◽  
Lolium Multiflorum ◽  
Rio Grande ◽  
Conservation Strategies ◽  
Temperate Climate ◽  
Annual Ryegrass ◽  
Rio Grande Do Sul ◽  
Genetic Diversity And Structure

Annual ryegrass is a temperate climate annual foraging grass, grown mostly in the South of Brazil, especially in the state of Rio Grande do Sul. Despite its importance, little is known about its genetic diversity, both within and among the populations cultivated. This knowledge is of fundamental importance for developing breeding and conservation strategies. The aim of this study was to characterize the genetic diversity and structure of four populations of annual ryegrass. Three of the populations were located in Rio Grande do Sul and the fourth in Uruguay. RAPD markers were used to study the genetic diversity and structure of these populations. Analysis of 375 individuals sampled from the populations, using six RAPD primers, generated a total of 82 amplified bands. They included 73 polymorphic bands (89,02%). The value of the total genetic diversity index obtained, <IMG SRC="/img/revistas/sa/v61n4/22157s1.gif">(0,71) was high, indicating the presence of wide genetic diversity in the four populations. Genetic structure analysis revealed that 98% of total diversity is intrapopulational, whereas interpopulational genetic diversity was only 2%. These results suggest that before these populations separated, they had gone through a period of gene exchange and, even after the separation event, gene frequency stayed at levels similar to the original levels, with no differential selection for these genes in the different cultivation areas.

scholarly journals Genetic diversity and structure of Astrocaryum jauari (Mart.) palm in two Amazon river basins

2014 ◽  
Vol 14 (3) ◽  
pp. 166-173 ◽  
Author(s):  
Liliane D. Santos Oliveira ◽  
Santiago L. Ferreyra Ramos ◽  
Maria T. Gomes Lopes ◽  
Gabriel Dequigiovanni ◽  
Elizabeth Ann Veasey ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Microsatellite Loci ◽  
Plant Material ◽  
Spatial Genetic Structure ◽  
River Basins ◽  
Genetic Analyses ◽  
Main River ◽  
Genetic Diversity And Structure

Astrocaryum jauari is a non-domesticated palm that is exploited by poachers. Our objective was to investigate the organization of the geneticdiversity and structure of three A. jauari populations. The study was carried out in the state of Amazonas, between the municipalities of Coari and Manaus. Nine microsatellite loci were used for the genetic analyses. High genetic variation was found, with a mean number of alleles per locus varying from 3.9 to 4.4. The average observed heterozygosity, varying from 0.71 to 0.78, was higher than expected. No spatial genetic structure was detected, since only one cluster was observed. Our results indicate a possible dispersion strategy and suggest that conservation measures of this species should focus mainly on the populations found at the end of the main river (Solimões) where most of the plant material originating from the headwaters of the tributaries of this river is concentrated.

scholarly journals Population genetic structure of the Natterjack toad (Epidalea calamita) in Ireland: implications for conservation management

2021 ◽  
Author(s):  
Marina Reyne ◽  
Kara Dicks ◽  
Claire McFarlane ◽  
Aurélie Aubry ◽  
Mark Emmerson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Population Genetic ◽  
Species Conservation ◽  
Conservation Strategies ◽  
Population Declines ◽  
Effective Population ◽  
Genetic Structuring ◽  
Genetic Diversity And Structure ◽  
Epidalea Calamita

AbstractMolecular methods can play a crucial role in species management and conservation. Despite the usefulness of genetic approaches, they are often not explicitly included as part of species recovery plans and conservation practises. The Natterjack toad (Epidalea calamita) is regionally Red-Listed as Endangered in Ireland. The species is declining and is now present at just seven sites within a highly restricted range. This study used 13 highly polymorphic microsatellite markers to analyse the population genetic diversity and structure. Genetic diversity was high with expected heterozygosity between 0.55 and 0.61 and allelic richness between 4.77 and 5.92. Effective population sizes were small (Ne < 100 individuals), but not abnormal for pond breeding amphibians. However, there was no evidence of historical or contemporary genetic bottlenecks or high levels of inbreeding. We identified a positive relationship between Ne and breeding pond surface area, suggesting that environmental factors are a key determinant of population size. Significant genetic structuring was detected throughout the species’ range, and we identified four genetic entities that should be considered in the species’ conservation strategies. Management should focus on preventing further population declines and future loss of genetic diversity overall and within genetic entities while maintaining adequate local effective population size through site-specific protection, human-mediated translocations and head-start programs. The apparent high levels of genetic variation give hope for the conservation of Ireland’s rarest amphibian if appropriately protected and managed.

Comparative Genetic Diversity and Structure of the Rhus Gall Aphid Schlechtendalia Chinensis and Its Host-Plant Rhus Chinensis

2021 ◽  
Author(s):  
Zhu Ren ◽  
Hong He ◽  
Yang Zhang ◽  
Xu Su
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Host Plant ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Rhus Chinensis ◽  
Genetic Diversity And Structure ◽  
Distance Model

Abstract Studying the population genetic structure of both parasites and their host-plants is expected to yield new valuable insights into their coevolution. In this study, we examined and compared the population genetic diversity and structure of 12 populations of the Rhus gall aphid, Schlechtendalia chinensis, and its host-plant, Rhus chinensis, using amplified fragment length polymorphism (AFLP) markers. AMOVA analysis showed that the genetic variance of the aphid and its host-plant were both higher within populations compared to that among them, suggesting that a co-evolutionary history has yielded similar patterns of population genetic structure. We did not detect significant correlation between genetic and geographic distance for either the aphid or host-plant populations, therefore rejecting an isolation by distance model for the demographic histories of the two species. However, our results appeared to suggest that genetically diverse host -plant Rhus populations correlated to similarly genetically diverse populations of gall aphid parasites.

scholarly journals High genetic diversity and strong genetic structure of Strongyllodes variegatus (Coleoptera: Nitidulidae) demonstrate the population history of its distribution in oilseed rape production areas in China

2020 ◽  
Author(s):  
HaiXia Zhan ◽  
ZhongPing Hao ◽  
Rui Tang ◽  
LiNi Zhu ◽  
JingJiang Zhou ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Oilseed Rape ◽  
Population Genetic ◽  
Distribution Analysis ◽  
Geographical Distance ◽  
Population Structure Analysis ◽  
Geographical Regions ◽  
Genetic Diversity And Structure ◽  
Production Areas

Abstract Background: Strongyllodes variegatus (Fairmaire) is a major insect pest of oilseed rape in China. Despite its economic importance, the contribution of its population genetics in the development of suitable protection control strategy for oilseed rape crops is poorlys tudied. Using the sequences mitochondrial DNA cytochrome c oxidase subunit I (COI ) and cytochrome b (Cytb ) as genetic markers, we analyzed population genetic diversity and structure of 437 individuals collected from 15 S. variegates populations located in different oilseed rape production areas in China. In addition, we estimated the demographic history using neutrality test and mismatch distribution analysis. Results: The high level of genetic diversity was detected among the COI and Cytb sequences of S. variegates . The population structure analysis strongly suggested three distinct genetic and geographical regions in China with limited gene flow. The Mantel test showed that the genetic distance was greatly influenced by the geographical distance. The demographic analyses showed that S. variegates experienced population fluctuation during the Pleistocene Epoch, which was likely to be related to the climatic changes. Conclusion: Overall, these results demonstrate that the strong population genetic structure of S. variegates in China may is attributed to the isolation through the geographical distance among populations, their weak flight capacity and subsequently adaptation to the regional ecological conditions.

Population genetic structure and gene flow of Adélie penguins (Pygoscelis adeliae) breeding throughout the western Antarctic Peninsula

2017 ◽  
Vol 29 (6) ◽  
pp. 499-510 ◽  
Author(s):  
Kristen B. Gorman ◽  
Sandra L. Talbot ◽  
Sarah A. Sonsthagen ◽  
George K. Sage ◽  
Meg C. Gravely ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Antarctic Peninsula ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Western Antarctic Peninsula ◽  
Pygoscelis Adeliae ◽  
Adélie Penguins

AbstractAdélie penguins (Pygoscelis adeliae) are responding to ocean–climate variability throughout the marine ecosystem of the western Antarctic Peninsula (WAP) where some breeding colonies have declined by 80%. Nuclear and mitochondrial DNA (mtDNA) markers were used to understand historical population genetic structure and gene flow given relatively recent and continuing reductions in sea ice habitats and changes in numbers of breeding adults at colonies throughout the WAP. Genetic diversity, spatial genetic structure, genetic signatures of fluctuations in population demography and gene flow were assessed in four regional Adélie penguin colonies. The analyses indicated little genetic structure overall based on bi-parentally inherited microsatellite markers (FST=-0.006–0.004). No significant variance was observed in overall haplotype frequency (mtDNAΦST=0.017;P=0.112). Some comparisons with Charcot Island were significant, suggestive of female-biased philopatry. Estimates of gene flow based on a two-population coalescent model were asymmetrical from the species’ regional core to its northern range. Breeding Adélie penguins of the WAP are a panmictic population and hold adequate genetic diversity and dispersal capacity to be resilient to environmental change.

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