scholarly journals Landscape and climatic features drive genetic differentiation processes in a South American coastal plant

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gustavo A. Silva-Arias ◽  
Lina Caballero-Villalobos ◽  
Giovanna C. Giudicelli ◽  
Loreta B. Freitas
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Coastal Plain ◽  
Atlantic Coastal Plain ◽  
Water Bodies ◽  
Marginal Populations ◽  
Landscape Features ◽  
Precipitation Seasonality ◽  
Isolation By Environment

Abstract Background Historical and ecological processes shape patterns of genetic diversity in plant species. Colonization to new environments and geographical landscape features determine, amongst other factors, genetic diversity within- and differentiation between-populations. We analyse the genetic diversity and population structure of Calibrachoa heterophylla to infer the influence of abiotic landscape features on the level of gene flow in this coastal species of the South Atlantic Coastal Plain. Results The C. heterophylla populations located on early-deposited coastal plain regions show higher genetic diversity than those closer to the sea. The genetic differentiation follows a pattern of isolation-by-distance. Landscape features, such as water bodies and wind corridors, and geographical distances equally explain the observed genetic differentiation, whereas the precipitation seasonality exhibits a strong signal for isolation-by-environment in marginal populations. The estimated levels of gene flow suggest that marginal populations had restricted immigration rates enhancing differentiation. Conclusions Topographical features related to coastal plain deposition history influence population differentiation in C. heterophylla. Gene flow is mainly restricted to nearby populations and facilitated by wind fields, albeit without any apparent influence of large water bodies. Furthermore, differential rainfall regimes in marginal populations seem to promote genetic differentiation.

scholarly journals Landscape and climatic features drive genetic differentiation processes in a South American coastal plant

2020 ◽  
Author(s):  
Gustavo A. Silva-Arias ◽  
Lina Caballero-Villalobos ◽  
Giovanna C. Giudicelli ◽  
Loreta B. Freitas
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Coastal Plain ◽  
Population Differentiation ◽  
Water Bodies ◽  
Marginal Populations ◽  
Landscape Features ◽  
Precipitation Seasonality ◽  
Isolation By Environment

ABSTRACTBackground and aimsHistorical and ecological processes shaped the patterns of genetic diversity in plant species; among these, colonization to new environments such as coastal regions generate multiple signals of interest to understand the influence of landscape features on the population differentiation.MethodsWe analysed the genetic diversity and population structure of Calibrachoa heterophylla to infer the influence of abiotic landscape features on this coastal species’ gene flow in the South Atlantic Coastal Plain (SACP). We used ten microsatellite loci to genotype 253 individuals from 15 populations, covering the species’ entire geographical range. We applied population genetics analyses to determine population diversity and structure along the SACP, migration model inference and correlative analyses to disentangle the most likely drivers of gene flow in the SACP.Key ResultsThe C. heterophylla populations located more distantly from the seashore showed higher genetic diversity than those closer to the sea. The genetic differentiation had a consistent signal of isolation-by-distance. Landscape features, such as water bodies and wind corridors, and raw geographical distances equally explained the genetic differentiation, whereas the precipitation seasonality showed a strong signal for isolation-by-environment in marginal populations. The estimated gene flow suggested that marginal populations had restricted immigration rates, which could enhance the genetic differentiation.ConclusionsThe influence of topographical features in population differentiation in C. heterophylla is related with the history of the coastal plain deposition. Gene flow is mainly restricted to nearby populations and facilitated by wind fields but with no apparent influence of large water bodies. Furthermore, differential rainfall regimes in marginal populations can promote local genetic differentiation.

scholarly journals Influence of isolation by environment and landscape heterogeneity on genetic structure of wild rice Zizania latifolia along a latitudinal gradient

2020 ◽  
Author(s):  
Godfrey Kinyori Wagutu ◽  
Xiangrong Fan ◽  
Wenlong Fu ◽  
Wei Li ◽  
Yuanyuan Chen
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Local Adaptation ◽  
Landscape Heterogeneity ◽  
Maximum Temperature ◽  
Zizania Latifolia ◽  
Precipitation Seasonality ◽  
Isolation By Environment

AbstractGlobal aquatic habitats are undergoing rapid degradation and fragmentation as a result of land-use change and climate change. Understanding the genetic variability and adaptive potential of aquatic plant species is thus important for conservation purposes. In this study, we investigated the role of environment, landscape heterogeneity and geographical distance in shaping the genetic structure of 28 natural populations of Zizania latifolia (Griseb.) Turcz. Ex Stapf in China based on 25 microsatellite markers. Genetic structure was investigated by analysis of molecular variance (AMOVA), estimation of FST, Bayesian clustering and Thermodynamic Integration (TI) methods. Isolation by environment (IBE), isolation by resistance (IBR) and isolation by distance (IBD) hypotheses were compared using a reciprocal causal model (RCM). Further, generalized linear models and spatially explicit mixed models, by using geographic, landscape and genetic variables, were developed to elucidate the role of environment in driving Z. latifolia genetic diversity. The genetic differentiation across all populations was high: FST = 0.579; Øpt = 0.578. RCM exclusively supported IBE in shaping genetic structuring, only partial support for IBR, but not for IBD. Maximum temperature of the warmest month and precipitation seasonality were the plausible parameters responsible for genetic diversity. After controlling for spatial effect and landscape complexity, precipitation seasonality was significantly associated with genetic diversity. Based on these findings, genetic structure of Z. latifolia across China seem to be as a result of local adaptation. Environmental gradient and topographical barriers, rather than geographical isolation, influence genetic differentiation of aquatic species across China resulting in instances of local adaptation.

scholarly journals Evolutionary history and genetic connectivity across highly fragmented populations of an endangered daisy

Heredity ◽  
2021 ◽  
Author(s):  
Yael S. Rodger ◽  
Alexandra Pavlova ◽  
Steve Sinclair ◽  
Melinda Pickup ◽  
Paul Sunnucks
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Evolutionary History ◽  
Livestock Grazing ◽  
Genetic Connectivity ◽  
Evolutionary Divergence ◽  
Common Component ◽  
A Genome ◽  
Eastern Australia

AbstractConservation management can be aided by knowledge of genetic diversity and evolutionary history, so that ecological and evolutionary processes can be preserved. The Button Wrinklewort daisy (Rutidosis leptorrhynchoides) was a common component of grassy ecosystems in south-eastern Australia. It is now endangered due to extensive habitat loss and the impacts of livestock grazing, and is currently restricted to a few small populations in two regions >500 km apart, one in Victoria, the other in the Australian Capital Territory and nearby New South Wales (ACT/NSW). Using a genome-wide SNP dataset, we assessed patterns of genetic structure and genetic differentiation of 12 natural diploid populations. We estimated intrapopulation genetic diversity to scope sources for genetic management. Bayesian clustering and principal coordinate analyses showed strong population genetic differentiation between the two regions, and substantial substructure within ACT/NSW. A coalescent tree-building approach implemented in SNAPP indicated evolutionary divergence between the two distant regions. Among the populations screened, the last two known remaining Victorian populations had the highest genetic diversity, despite having among the lowest recent census sizes. A maximum likelihood population tree method implemented in TreeMix suggested little or no recent gene flow except potentially between very close neighbours. Populations that were more genetically distinctive had lower genetic diversity, suggesting that drift in isolation is likely driving population differentiation though loss of diversity, hence re-establishing gene flow among them is desirable. These results provide background knowledge for evidence-based conservation and support genetic rescue within and between regions to elevate genetic diversity and alleviate inbreeding.

Genetic structure and proposed conservation strategy for natural populations of Calycanthus chinensis Cheng et S.Y. Chang (Calycanthaceae)

2008 ◽  
Vol 88 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Chu-Chuan Fan ◽  
Nicola Pecchioni ◽  
Long-Qing Chen
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Genetic Distance ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Natural Populations ◽  
Population Level ◽  
Conservation Strategy ◽  
Information Index

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD

scholarly journals Genetic structure and diversity in Juniperus communis populations in Saxony, Germany

2016 ◽  
Vol 42 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Stefanie Reim ◽  
Frank Lochschmidt ◽  
Anke Proft ◽  
Ute Tröber ◽  
Heino Wolf
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Land Use Changes ◽  
Rapid Decline ◽  
Restricted Gene Flow ◽  
Negative Effects ◽  
Population Isolation ◽  
High Genetic Diversity ◽  
Chloroplast Markers

Abstract In recent years, land use changes led to a rapid decline and fragmentation of J. communis populations in Germany. Population isolation may lead to a restricted gene flow and, further, to negative effects on genetic variation. In this study, genetic diversity and population structure in seven fragmented J. communis populations in Saxony, Germany, were investigated using nuclear microsatellites (nSSR) and chloroplast single nucleotide polymorphism (cpSNP). In all Saxony J. communis populations, a high genetic diversity was determined but no population differentiation could be detected whatever method was applied (Bayesian cluster analysis, F-statistics, AMOVA). The same was true for three J. communis out-group samples originating from Italy, Slovakia and Norway, which also showed high genetic diversity and low genetic differences regarding other J. communis populations. Low genetic differentiation among the J. communis populations ascertained with nuclear and chloroplast markers indicated high levels of gene flow by pollen and also by seeds between the sampled locations. Low genetic differentiation may also provide an indicator of Juniper survival during the last glacial maximum (LGM) in Europe. The results of this study serve as a basis for the implementation of appropriate conservation measures in Saxony.

scholarly journals High-Level Gene Flow Restricts Genetic Differentiation in Dairy Cattle Populations in Thailand: Insights from Large-Scale Mt D-Loop Sequencing

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1680
Author(s):  
Nattakan Ariyaraphong ◽  
Nararat Laopichienpong ◽  
Worapong Singchat ◽  
Thitipong Panthum ◽  
Syed Farhan Ahmad ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Dairy Cattle ◽  
Large Scale ◽  
Genetic Relationships ◽  
Extensive Study ◽  
Distribution Analysis ◽  
Cattle Breeds ◽  
D Loop

Domestication and artificial selection lead to the development of genetically divergent cattle breeds or hybrids that exhibit specific patterns of genetic diversity and population structure. Recently developed mitochondrial markers have allowed investigation of cattle diversity worldwide; however, an extensive study on the population-level genetic diversity and demography of dairy cattle in Thailand is still needed. Mitochondrial D-loop sequences were obtained from 179 individuals (hybrids of Bos taurus and B. indicus) sampled from nine different provinces. Fifty-one haplotypes, of which most were classified in haplogroup “I”, were found across all nine populations. All sampled populations showed severely reduced degrees of genetic differentiation, and low nucleotide diversity was observed in populations from central Thailand. Populations that originated from adjacent geographical areas tended to show high gene flow, as revealed by patterns of weak network structuring. Mismatch distribution analysis was suggestive of a stable population, with the recent occurrence of a slight expansion event. The results provide insights into the origins and the genetic relationships among local Thai cattle breeds and will be useful for guiding management of cattle breeding in Thailand.

scholarly journals Ocean Currents Drove Genetic Structure of Seven Dominant Mangrove Species Along the Coastlines of Southern China

2021 ◽  
Vol 12 ◽  
Author(s):  
Qifang Geng ◽  
Zhongsheng Wang ◽  
Jianmin Tao ◽  
Megumi K. Kimura ◽  
Hong Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
South China ◽  
Population Genetic ◽  
Ocean Currents ◽  
Mangrove Species ◽  
Contemporary Gene Flow ◽  
Low Levels ◽  
Oceanic Currents

Mangrove forest ecosystems, which provide important ecological services for marine environments and human activities, are being destroyed worldwide at an alarming rate. The objective of our study was to use molecular data and analytical techniques to separate the effects of historical and contemporary processes on the distribution of mangroves and patterns of population genetic differentiation. Seven mangrove species (Acanthus ilicifolius, Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorrhiza, Kandelia obovata, Lumnitzera racemosa, and Rhizophora stylosa), which are predominant along the coastlines of South China, were genotyped at nuclear (nSSR) and chloroplast (cpSSR) microsatellite markers. We estimated historical and contemporary gene flow, the genetic diversity and population structure of seven mangrove species in China. All of these seven species exhibited few haplotypes, low levels of genetic diversity (HE = 0.160–0.361, with the exception of K. obovata) and high levels of inbreeding (FIS = 0.104–0.637), which may be due to their marginal geographical distribution, human-driven and natural stressors on habitat loss and fragmentation. The distribution patterns of haplotypes and population genetic structures of seven mangrove species in China suggest historical connectivity between populations over a large geographic area. In contrast, significant genetic differentiation [FST = 0.165–0.629 (nSSR); GST = 0.173–0.923 (cpSSR)] indicates that populations of mangroves are isolated from one another with low levels of contemporary gene flow among populations. Our results suggest that populations of mangroves were historically more widely inter-connected and have recently been isolated, likely through a combination of ocean currents and human activities. In addition, genetic admixture in Beibu Gulf populations and populations surrounding Hainan Island and southern mainland China were attributed to asymmetric gene flow along prevailing oceanic currents in China in historical times. Even ocean currents promote genetic exchanges among mangrove populations, which are still unable to offset the effects of natural and anthropogenic fragmentation. The recent isolation and lack of gene flow among populations of mangroves may affect their long-term survival along the coastlines of South China. Our study enhances the understanding of oceanic currents contributing to population connectivity, and the effects of anthropogenic and natural habitat fragmentation on mangroves, thereby informing future conservation efforts and seascape genetics toward mangroves.

scholarly journals Gender-based Genetic Variability of Ailanthus excelsa Roxb, Populations Using, RAPD, ISSR and SCoT Markers

2020 ◽  
pp. 75-83
Author(s):  
Shabnam Bano ◽  
Sumaiya Ansari ◽  
Meena Choudhary ◽  
U. K. Tomar
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Gene Diversity ◽  
Dna Amplification ◽  
Ailanthus Excelsa ◽  
High Gene Flow ◽  
Diversity Assessment ◽  
High Gene ◽  
Gender Based

Ailanthus excelsa Roxb. is an economically important and multipurpose dioecious tree species of India, mainly used for fodder and timber. Gender-based genetic diversity of five populations of two sites (Jodhpur, Rajasthan and Deesa, Gujarat) of A. excelsa was assessed. A total of 42 RAPD, 20 ISSR and 23 SCoT primers were screened for DNA amplification of 232 individuals. Out of which only 25 primers (13 RAPD, 6 ISSR and 6 SCoT) were found polymorphic. The SCoT markers were showed the highest value for PIC, MI, Rp value, Nei’s gene diversity and Shannon’s index, as compared with the other two markers. Female individuals in all five populations had slightly higher genetic diversity as compared with male individuals. A high level of genetic diversity (55%) was detected within the populations of male and female individuals. High gene flow (6.70) and low genetic differentiation (0.069) values were found between Jodhpur and Deesa sites. Principal component analysis for all populations were accounted for 48.7% of the genetic variation. The Mantel test showed significant correlation (R = 0.178, P = .01) between genetic and geographic distances. The present study showed that SCoT markers were best for genetic diversity assessment in A. excelsa over RAPD and ISSR markers. High gene flow and low genetic differentiation in A. excelsa indicates its poor population fragmentation despite long geographic distances.

scholarly journals cpDNA-Gene-Sequence-Based Genetic Diversity, Population Structure, and Gene Flow Analysis of Ethiopian Lowland Bamboo (Bambusinea: Oxytenanthera abyssinica (A. Rich.) Munro)

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Oumer Abdie Oumer ◽  
Kassahun Tesfaye ◽  
Tileye Feyissa ◽  
Dagnew Yibeyen ◽  
Jayaraman Durai ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Gc Content ◽  
Wood Products ◽  
Population Structure Analysis ◽  
The World ◽  
Oxytenanthera Abyssinica ◽  
Metekel Zone

Background. As a member of Poaceae and subfamily Bambusoideae, Ethiopian lowland bamboo (Oxytenanthera abyssinica) is one of the most important nontimber forest resources or a potential alternative to wood and wood products. Ethiopia contributes 86% of the total area of bamboo on the continent, Africa, and 7% of the world. O. abyssinica in Ethiopia accounts for 85% of the total national coverage of bamboo. Several studies have been performed on the genetic diversity and population structure analysis of various bamboo species throughout the world but almost nothing in Ethiopia and O. abyssinica. Methods. Young fresh leaves of O. abyssinica from thirteen natural lowland bamboo growing areas across the country were collected. DNA was isolated using a modified CTAB DNA isolation method. Three cpDNA gene sequences (matK, ndhF3, and rps16) were used for the study. PCR products were analyzed, purified, and pair-end sequenced to calculate AC/GC content, average number of nucleotide differences (k), nucleotide diversity (π) and population mutation rates per 100 sites ( θ w ), InDel (Insertion-Deletion), DNA divergence, gene flow, and genetic differentiation. Results. Metekel Zone was found to have extremely higher k, π, and θ w . Higher frequency of genetic differentiation was found between Metekel Zone vs. the distant populations. Higher frequency of gene flow was found between Assosa Zone vs. Oromia populations. Kurmuk haplotype from gaps or missing data considered and Bambasi haplotype from not considered has descendants around them. Conclusion. Using sequences of cpDNA genes, populations of O. abyssinica collected in Ethiopia show clear diversity based on their geographic location. Metekel Zone was found to have the most diverse population, Assosa Zone has been found to be the source of evolution of O. abyssinica, and Gambella population shows a difference from other O. abyssinica populations.

High nuclear genetic differentiation, but low chloroplast diversity in a rare species, Aluta quadrata (Myrtaceae), with a disjunct distribution in the Pilbara, Western Australia

2016 ◽  
Vol 64 (8) ◽  
pp. 687 ◽  
Author(s):  
M. Byrne ◽  
D. J. Coates ◽  
B. M. Macdonald ◽  
M. Hankinson ◽  
S. M. McArthur ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Microsatellite Loci ◽  
Disjunct Distribution ◽  
Chloroplast Gene ◽  
Seed Sources ◽  
Chloroplast Haplotype ◽  
Haplotype Variation

Geographically separated populations may show high levels of genetic differentiation, depending on the levels of current and historical isolation. In the ancient landscape of the Pilbara region, there are few plant species with restricted distributions, and one such species, Aluta quadrata Rye & Trudgen, is restricted to three separate locations on the southern edge of the Hamersley Range. We investigated genetic diversity and differentiation among geographically isolated locations of A. quadrata, using 10 microsatellite loci to assess contemporary genetic structure, and sequences of seven chloroplast gene regions to infer historical isolation. Nuclear genetic diversity was moderate, with moderate to high genetic differentiation among the three locations, and low differentiation among populations within locations. In contrast, there was no detected variation in the chloroplast genome. The high genetic differentiation is consistent with limited contemporary connectivity among the geographically separated locations, although lack of chloroplast haplotype variation indicates that limited connectivity has occurred more recently and is not due to historical isolation. The level of differentiation suggests use of local seed sources for augmentation or establishment of populations within gene flow distance of existing populations, whereas an experimental translocation established on more distant sites could use mixed seed sources to maximise genetic diversity.

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