scholarly journals The Patterns and Puzzles of Genetic Diversity of Endangered Freshwater Mussel Unio crassus Philipsson, 1788 Populations from Vistula and Neman Drainages (Eastern Central Europe)

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 119
Author(s):  
Adrianna Kilikowska ◽  
Monika Mioduchowska ◽  
Anna Wysocka ◽  
Agnieszka Kaczmarczyk-Ziemba ◽  
Joanna Rychlińska ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Scales ◽  
Freshwater Mussel ◽  
Its Region ◽  
Strong Relationship ◽  
Mantel Test ◽  
Freshwater Ecosystems ◽  
Hierarchical Organization ◽  
Anthropogenic Factors

Mussels of the family Unionidae are important components of freshwater ecosystems. Alarmingly, the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species identifies almost 200 unionid species as extinct, endangered, or threatened. Their decline is the result of human impact on freshwater habitats, and the decrease of host fish populations. The Thick Shelled River Mussel Unio crassus Philipsson, 1788 is one of the examples that has been reported to show a dramatic decline of populations. Hierarchical organization of riverine systems is supposed to reflect the genetic structure of populations inhabiting them. The main goal of this study was an assessment of the U. crassus genetic diversity in river ecosystems using hierarchical analysis. Different molecular markers, the nuclear ribosomal internal transcribed spacer ITS region, and mitochondrial DNA genes (cox1 and ndh1), were used to examine the distribution of U. crassus among-population genetic variation at multiple spatial scales (within rivers, among rivers within drainages, and between drainages of the Neman and Vistula rivers). We found high genetic structure between both drainages suggesting that in the case of the analyzed U. crassus populations we were dealing with at least two different genetic units. Only about 4% of the mtDNA variation was due to differences among populations within drainages. However, comparison of population differentiation within drainages for mtDNA also showed some genetic structure among populations within the Vistula drainage. Only one haplotype was shared among all Polish populations whereas the remainder were unique for each population despite the hydrological connection. Interestingly, some haplotypes were present in both drainages. In the case of U. crassus populations under study, the Mantel test revealed a relatively strong relationship between genetic and geographical distances. However, in detail, the pattern of genetic diversity seems to be much more complicated. Therefore, we suggest that the observed pattern of U. crassus genetic diversity distribution is shaped by both historical and current factors i.e. different routes of post glacial colonization and history of drainage systems, historical gene flow, and more recent habitat fragmentation due to anthropogenic factors.

Population genetic structure and migration patterns of Liriomyza sativae in China: moderate subdivision and no Bridgehead effect revealed by microsatellites

2015 ◽  
Vol 106 (1) ◽  
pp. 114-123 ◽  
Author(s):  
X.-T. Tang ◽  
Y. Ji ◽  
Y.-W. Chang ◽  
Y. Shen ◽  
Z.-H. Tian ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Mantel Test ◽  
Invasive Pest ◽  
Migration Patterns ◽  
Liriomyza Sativae ◽  
And Migration

AbstractWhile Liriomyza sativae (Diptera: Agromyzidae), an important invasive pest of ornamentals and vegetables has been found in China for the past two decades, few studies have focused on its genetics or route of invasive. In this study, we collected 288 L. sativae individuals across 12 provinces to explore its population genetic structure and migration patterns in China using seven microsatellites. We found relatively low levels of genetic diversity but moderate population genetic structure (0.05 < FST < 0.15) in L. sativae from China. All populations deviated significantly from the Hardy–Weinberg equilibrium due to heterozygote deficiency. Molecular variance analysis revealed that more than 89% of variation was among samples within populations. A UPGMA dendrogram revealed that SH and GXNN populations formed one cluster separate from the other populations, which is in accordance with STRUCTURE and GENELAND analyses. A Mantel test indicated that genetic distance was not correlated to geographic distance (r = −0.0814, P = 0.7610), coupled with high levels of gene flow (M = 40.1–817.7), suggesting a possible anthropogenic influence on the spread of L. sativae in China and on the effect of hosts. The trend of asymmetrical gene flow was from southern to northern populations in general and did not exhibit a Bridgehead effect during the course of invasion, as can be seen by the low genetic diversity of southern populations.

scholarly journals The interacting effects of genetic variation in Geranium subg. Geranium (Geraniaceae) using scot molecular markers

Caryologia ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 141-150
Author(s):  
Bo Shi ◽  
Majid Khayatnezhad ◽  
Abdul Shakoor
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Biological Diversity ◽  
Isolation By Distance ◽  
Morphological Characters ◽  
Mantel Test ◽  
Conservation Strategies ◽  
High Genetic Diversity ◽  
Information Index ◽  
Narrow Endemic

One of the most crucial aspects of biological diversity for conservation strategies is genetic diversity, particularly in rare and narrow endemic species. Our study is the first attempt to utilize SCoT markers to check the genetic diversity in Iran. We used 115 plant samples. Our objectives were 1) to check genetic diversity among Geranium species 2) Genetic structure of the Geranium 3) Do the Geranium species exchange genes? 4) To detect isolation by distance among the Geranium species. We used traditional morphological and molecular methods to assess genetic diversity and genetic structure in the Geranium species. A total of 129 amplified polymorphic bands were generated across 13 Geranium species. The size of the amplified fragments ranged from 150 to 3000 bp. G. stepporum showed the highest values for the effective number of alleles (Ne = 1.30) and Shannon information index (I =0.35). Significant ANOVA results (P <0.01) showed differences in quantitative morphological characters in plant species. G. sylvaticum showed high genetic diversity. Mantel test showed a significant correlation (r = 0.17, p=0.0002) between genetic distance and geographical distance, so isolation by distance (IBD) occurred among the Geranium species. According to the SCoT markers analysis, G. kotschyi and G. dissectum had the lowest similarity, and the species of G. sylvaticum and G. pratense had the highest similarity. The present study revealed that a combination of morphological and SCoT methods could distinguish the species of Geranium.

Guiding Species Recovery through Assessment of Spatial and Temporal Population Genetic Structure of Two Critically Endangered Freshwater Mussel Species (Bivalvia: Unionidae)

2021 ◽  
Author(s):  
Jess Walter Jones ◽  
Timothy W. Lane ◽  
Nathan Johnson ◽  
Eric M. Hallerman
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Spatial Scales ◽  
Freshwater Mussel ◽  
Genetic Data ◽  
Temporal Scale ◽  
Critically Endangered ◽  
Frequency Change ◽  
Mussel Species ◽  
Clinch River

Abstract The Cumberlandian Combshell (Epioblasma brevidens) and Oyster Mussel (E. capsaeformis) are critically endangered freshwater mussel species native to the Tennessee and Cumberland River drainages, major tributaries of the Ohio River in the eastern United States. The Clinch River in northeastern Tennessee (TN) and southwestern Virginia (VA) harbors the only remaining stronghold population for either species, containing tens of thousands of individuals per species; however, a few smaller populations are still extant in other rivers. We collected and analyzed genetic data to assist with population restoration and recovery planning for both species. We used an 888 base-pair sequence of the mitochondrial NADH dehydrogenase 1 (ND1) gene and ten nuclear DNA microsatellite loci to assess patterns of genetic differentiation and diversity in populations at small and large spatial scales, and at a 9-year (2004 to 2013) temporal scale, which showed how quickly these populations can diverge from each other in a short time period. Intraspecific mitochondrial DNA (mtDNA) and microsatellite DNA variation was higher in E. capsaeformis than in E. brevidens. These two species have maintained quite different levels of genetic diversity within their Clinch River stronghold and in their smaller peripheral populations in the Big South Fork Cumberland and Nolichucky rivers, TN. For instance, with only three mtDNA haplotypes detected overall across populations, E. brevidens’ capacity for maintaining genetic diversity appears to be less than that of E. capsaeformis, which had 18 haplotypes. At the relatively small spatial scales (15-30 kilometers) investigated in the Clinch River, demes of both species exhibited minimal genetic differentiation in either the 2004 or 2013 sampling periods, typically <0.02 based on FST and <0.1 based on Jost’s D. Our genetic data suggest that mussels at the numerous shoals in a 32-kilometer section of the Clinch River comprise a single, large population of each respective species with very high gene-flow among individual demes. However, we also observed a high level of genetic differentiation among demes at the 9-year temporal scale, with differentiation metrics for E. brevidens (D = 0.47 and FST = 0.12) and E. capsaeformis (D = 0.31 and FST = 0.05) proving higher than the within-year values. This result strongly suggests that genetic drift is playing an important role in allele frequency change over time in these populations. At the spatial and temporal scales investigated in this study, various demographic, life history, and environmental factors are influencing maintenance of genetic variation and need to be considered during conservation planning for each species.

Prominent genetic structure across native and introduced ranges of Pluchea indica, a mangrove associate, as revealed by microsatellite markers

2020 ◽  
Vol 13 (3) ◽  
pp. 341-353
Author(s):  
Yuting Lin ◽  
Achyut Kumar Banerjee ◽  
Haidan Wu ◽  
Fengxiao Tan ◽  
Hui Feng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Spatial Scales ◽  
Large Spatial Scale ◽  
Introduced Range ◽  
Native And Introduced Ranges ◽  
Mangrove Associate

Abstract Aims Pluchea indica is a mangrove-associate species, known for its medicinal properties in its native range and being invasive in part of its introduced range. This study aimed to assess geographic distribution of genetic variation of this species across its distribution range, identify the factors influencing its genetic structure and use this information to suggest conservation and management strategies in its native and introduced ranges, respectively. Methods We assessed the genetic diversity and population structure of 348 individuals from 31 populations across its native (Asia) and introduced (USA) ranges for 15 nuclear microsatellite loci. The spatial pattern of genetic variation was investigated at both large and regional spatial scales with the hypothesis that geographic distance and natural geographic barriers would influence the population structure with varying levels of differentiation across spatial scales. Important Findings We found relatively high genetic diversity at the population level and pronounced genetic differentiation in P. indica, as compared with the genetic diversity parameters of mangroves and mangrove associates in this region. Most of the populations showed heterozygote deficiency, primarily due to inbreeding and impediment of gene flow. Analysis of population structures at large spatial scale revealed the presence of two major clusters across the species’ natural range separating populations in China from those in Indonesia, Malaysia, Singapore, Thailand, Cambodia and Philippines, and that the USA population might have been introduced from the population cluster in China. Genetic differentiation between populations was also observed at the regional scale. A large number of populations showed evidence of genetic bottleneck, thereby emphasizing the risk of local extinction. Based on these findings, our study recommends in situ conservation strategies, such as to prioritize populations for conservation actions and to maintain genetic diversity.

scholarly journals Patterns of Fine-Scale Spatial Genetic Structure and Pollen Dispersal in Giant Sequoia (Sequoiadendron giganteum)

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Rainbow DeSilva ◽  
Richard S. Dodd
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Pollen Dispersal ◽  
Detailed Examination ◽  
Background Information ◽  
Long Distance ◽  
Giant Sequoia ◽  
Sequoiadendron Giganteum

Research Highlights: Patterns of dispersal shape the distribution and temporal development of genetic diversity both within and among populations. In an era of unprecedented environmental change, the maintenance of extant genetic diversity is crucial to population persistence. Background and Objectives: We investigate patterns of pollen dispersal and spatial genetic structure within populations of giant sequoia (Sequoiadendron giganteum). Materials and Methods: The leaf genotypes of established trees from twelve populations were used to estimate the extent of spatial genetic structure within populations, as measured by the Sp statistic. We utilized progeny arrays from five populations to estimate mating parameters, the diversity of the pollen pool, and characteristics of pollen dispersal. Results: Our research indicates that giant sequoia is predominantly outcrossing, but exhibits moderate levels of bi-parental inbreeding (0.155). The diversity of the pollen pool is low, with an average of 7.5 pollen donors per mother tree. As revealed by the Sp-statistic, we find significant genetic structure in ten of twelve populations examined, which indicates the clustering of related individuals at fine spatial scales. Estimates of pollen and gene dispersal indicate predominantly local dispersal, with the majority of pollen dispersal <253 m, and with some populations showing fat-tailed dispersal curves, suggesting potential for long-distance dispersal. Conclusions: The research presented here represent the first detailed examination of the reproductive ecology of giant sequoia, which will provide necessary background information for the conservation of genetic resources in this species. We suggest that restoration planting can mitigate potential diversity loss from many giant sequoia populations.

Genetic structure and diversity of the black-throated finch (Poephila cincta) across its current range

2016 ◽  
Vol 64 (6) ◽  
pp. 375
Author(s):  
Lei Stanley Tang ◽  
Carolyn Smith-Keune ◽  
Anthony C. Grice ◽  
James M. Moloney ◽  
Britta Denise Hardesty
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Standard Error ◽  
Conservation Management ◽  
Spatial Scales ◽  
Mitochondrial Control Region ◽  
Population Connectivity ◽  
Population Declines ◽  
Genetic Structure And Diversity

Understanding the patterns of population connectivity and level of genetic diversity can facilitate the identification of both ecologically relevant populations and the spatial scales at which conservation management may need to focus. We quantified genetic variation within and among populations of black-throated finches across their current distribution. To quantify genetic structure and diversity, we genotyped 242 individuals from four populations using 14 polymorphic microsatellite markers and sequenced 25 individuals based on a 302-base-pair segment of mitochondrial control region. We found modest levels of genetic diversity (average allelic richness r = 4.37 ± 0.41 (standard error) and average heterozygosity HO = 0.42 ± 0.040 (standard error)) with no bottleneck signature among sampled populations. We identified two genetic groups that represent populations of two subspecies based on Bayesian clustering analysis and low levels of genetic differentiation based on pairwise genetic differentiation statistics (all FST, RST and Nei’s unbiased D values <0.1). Our data suggest that genetic exchange occurs among sampled populations despite recent population declines. Conservation efforts that focus on maintaining habitat connectivity and increasing habitat quality to ensure a high level of gene flow on a larger scale will improve the species’ ability to persist in changing landscapes. Conservation management should also support continuous monitoring of the bird to identify any rapid population declines as land-use intensification occurs throughout the species’ range.

scholarly journals Conservation status and a novel restoration of the endangered freshwater mussel Unio crassus Philipsson, 1788: Poland case

2021 ◽  
pp. 3
Author(s):  
Marianna Soroka ◽  
Barbara Wasowicz ◽  
Katarzyna Zając
Keyword(s):  
Genetic Diversity ◽  
Conservation Status ◽  
Freshwater Mussel ◽  
Freshwater Ecosystems ◽  
Anthropogenic Influence ◽  
Population Abundance ◽  
Protection Measures ◽  
Active Protection ◽  
New Localities ◽  
Improve Water Quality

Bivalves play an important part in freshwater ecosystems and improve water quality; the thick-shelled river mussel Unio crassus is classified as a bioindicator. Unfortunately, the species is regarded as endangered and is under species protection in the whole of Europe. The reasons for the drastic decline of its populations are: considerable eutrophication of waters, anthropogenic influence in its broad sense and the presence of invasive species. The life cycle of U. crassus includes the stage of larva which is an obligatory parasite of fish. This makes it possible for the species to disperse and populate new territories but it limits the development to places where appropriate host species are available. Intensive measures have been taken in Poland to protect U. crassus, while in France numerous new localities of the species have been bar-coded. In 2010–2014 active protection measures were taken in southern Poland, including inventorying, studies of genetic diversity and reintroductions. The project contributed to the increase in population abundance and in the number of localities of the thick-shelled river mussel, which resulted in a twofold increase in the range of occurrence of the species in the river. The procedures presented here can and should be used in further restitution of U. crassus not only in Poland but also elsewhere in Europe.

scholarly journals Genetic diversity and population structure of the endangered basal angiospermBrasenia schreberi(Cabombaceae) in China

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5296 ◽  
Author(s):  
Zhi-Zhong Li ◽  
Andrew W. Gichira ◽  
Qing-Feng Wang ◽  
Jin-Ming Chen
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Habitat Fragmentation ◽  
Glacial Refugia ◽  
Mantel Test ◽  
Ex Situ ◽  
Brasenia Schreberi ◽  
Genetic Diversity And Structure ◽  
Rare And Endangered

Brasenia schreberiJ.F. Gmelin (Cabombaceae), an aquatic herb that occurs in fragmented locations in China, is rare and endangered. Understanding its genetic diversity and structure is crucial for its conservation and management. In this study, 12 microsatellite markers were used to estimate the genetic diversity and variation in 21 populations ofB. schreberiin China. A total of 61 alleles were found; assessment of allelic richness (Ar = 1.92) and observed and expected heterozygosity (HO= 0.200,HE= 0.256) suggest lower genetic diversity compared to some endangered species, and higher variation was observed within populations (58.68%) rather than among populations (41.32%). No significant correlation between geographical and genetic distance among populations was detected (Mantel test,r= 0.0694;P= 0.7985), which may have likely resulted from barriers to gene flow (Nm = 0.361) that were produced by habitat fragmentation. However, Bayesian and neighbor-joining cluster analyses suggest a population genetic structure consisting of two clusters (I and II) or four subclusters (I-1, 2 and II-1, 2). The genetic structure and distribution ofB. schreberiin China may have involved glacial refugia that underwent range expansions, introgression, and habitat fragmentation. The findings of the present study emphasize the importance for both in situ and ex situ conservation efforts.

Sign in / Sign up

Export Citation Format

Share Document