scholarly journals Genetic diversity in rosewood saplings (Aniba rosaeodora ducke, Lauraceae): an ecological approach

2008 ◽  
Vol 38 (4) ◽  
pp. 707-714 ◽  
Author(s):  
Ronaldo Pereira Santos ◽  
Wilson Roberto Spironello ◽  
Paulo de Tarso Barbosa Sampaio
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Distribution Patterns ◽  
Ecological Approach ◽  
Adult Trees ◽  
High Incidence ◽  
Adult Tree ◽  
High Gene ◽  
Disturbed Forest ◽  
High Level

This article takes an ecological approach to the genetic diversity of Rosewood (Aniba rosaeodora Ducke) in a central Amazonian terra firme forest north of Manaus. Planted Rosewood setting, under partial shaded canopy, were assessed in terms of fruiting production, frugivory, and seed dispersal. Using RAPD molecular analysis procedures, the influence of the spatial distribution of adult trees on the genetic diversity (polymorphism) of saplings was assessed with genetic samples from 34 reproductive trees and 60 saplings. The density and distribution patterns the reproductive trees did not modify the sapling"s diversity (1.86%, AMOVA). Two types of adult tree dispersion were identified; i) clumped and ii) more widely dispersed. Polymorphism (77.5%) and gene flow were high between these. Although more sapling genetic variability in areas with a higher density of mature plants was not as high as expected, density did not affect the genetic diversity of samplings, indicating a high incidence of gene flow amongst trees. In planted Rosewood population (surrounded by low disturbed forest), fruiting trees experienced a high level of removal of seeds by toucans (Rhamphastidae), about of 50%. The high gene flow found among native trees suggested that toucans, promoting seed rain at short and long distances from maternal trees, actively contribute to the maintenance of genetic diversity within wild rosewood populations.

scholarly journals Genetic diversity of African clawless otters (Aonyx capensis) occurring in urbanised areas of Gauteng, South Africa

2019 ◽  
Vol 115 (7/8) ◽  
Author(s):  
Damian W. Ponsonby ◽  
M. Thabang Madisha ◽  
Schwaibold Schwaibold ◽  
Desiré L. Dalton
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
Gene Flow ◽  
Environmental Changes ◽  
Urban Expansion ◽  
Evolutionary Potential ◽  
Non Invasive ◽  
Faecal Samples ◽  
Physical Barriers ◽  
High Gene

Genetic diversity is the basis of the evolutionary potential of species to respond to environmental changes. However, restricting the movement of species can result in populations becoming less connected which can reduce gene flow and can subsequently result in a loss of genetic diversity. Urban expansion can lead to the fragmentation of habitats which affects the ability of species to move freely between areas. In this study, the genetic diversity of the African clawless otter (Aonyx capensis) in Gauteng (South Africa) was assessed using non-invasive sampling techniques. DNA was extracted from spraint (faecal) samples collected along nine rivers and genotyped using 10 microsatellites to assess population structure and genetic diversity. Samples were grouped based on locality and by catchment to determine whether isolated subpopulations exist. Genetic diversity of A. capensis in Gauteng was found to be low (mean observed heterozygosity (Ho)=0.309). Analysis of genetic structure provides support for the otter populations being panmictic with high gene flow between populations from different rivers. Results from the study indicate that the movement of A. capensis is not affected by physical barriers in urbanised areas. However, because the genetic diversity of the species in the study area is low, these animals may not be able to cope with future environmental changes.

scholarly journals Genetic Diversity and Population Structure of Endangered Catfish Rita rita (Hamilton, 1822) Revealed by Heterologous DNA Microsatellite Markers

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
MUHAMMAD FORHAD ALI ◽  
◽  
MD. RAFIQUL ISLAM SARDER ◽  
MOHAMMAD MATIUR RAHMAN ◽  
MD. FAZLUL AWAL MOLLAH ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Genetic Difference ◽  
Information Index ◽  
Hardy Weinberg Equilibrium ◽  
High Gene ◽  
High Level ◽  
Dna Microsatellite

Genetic information is essential for conservation and future aquaculture development of the endangered catfish Rita rita (Hamilton, 1822). Two hundred catfish, R. rita, 50 from four rivers, the Old Brahmaputra, Jamuna, Meghna and Kangsa were collected and analysed to evaluate the genetic diversity and population structure using five microsatellite primers (Cba06-KUL, Cba08-KUL, Cba09-KUL, Phy03-KUL and Phy07-KUL). Four of the five amplified loci were found polymorphic (P95) in all the populations and 46 alleles were recorded with 9 to 14 alleles per locus. Differences were observed in the total number of alleles ranging from 41 to 44, effective number of alleles from 29.96 to 37.46, observed heterozygosity from 0.57 to 0.76, Shannon’s information index from 2.09 to 2.30 and polymorphic information content from 0.84 to 0.88 among the four populations. Results exposed the highest levels of genetic diversity in the Meghna population while the lowest in the Kangsa population of R. rita. All the populations were significantly deviated (P < 0.001) from the Hardy-Weinberg equilibrium for all the loci. Nei’s genetic distance between populations ranged 0.007 to 0.017 with low overall genetic difference FST = 0.011 and high gene flow Nm = 24.333, indicating that R. rita populations were not subdivided. This study revealed a high level of gene diversity with deficiency in genetic heterogeneity in all the populations of R. rita, emphasising natural management, conservation and rehabilitation measures of this species.

scholarly journals Phylogeography and Genetic Diversity of Humpback Grouper Cromileptes altivelis based on Cytochrome C Oxidase I

2012 ◽  
Vol 14 (1) ◽  
pp. 47
Author(s):  
Agus Hery Susanto ◽  
Agus Nuryanto ◽  
Petrus Hary Tjahja Soedibja
Keyword(s):  
Genetic Diversity ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Nucleotide Diversity ◽  
Asia Pacific ◽  
Cytochrome C Oxidase I ◽  
Base Pairs ◽  
High Gene ◽  
Fish Group ◽  
High Level

Humpback grouper is one of the most popular fish group in the international live trade in Asia-Pacific regions. The price for one kilogramlive of humpback grouper, especially in Spermonde Archipelago South of Sulawesi, is range from 350.000-400.000 IDR, whereas in theretail level in Hong Kong the price was about 92 US$. This condition leads to the reduction of nature population due to overexploitation.Population decreasing due to overexploitation may cause loss of genetic diversity within population and lead to reduce of potentialadaptive, population resistance, and productivity. Therefore, it is important to do some efforts to avoid adverse effect of overexploitationon humpback grouper population in Indonesia. One of the valuable efforts is providing genetic information such as phylogeography andgenetic diversity of humpback grouper Cromileptes altivelis. Analysis was based on 618 base pairs fragment of cytochrome c oxidase I genefrom 36 individuals (sequences) of Cromileptes altivelis collected at four different sites (e.g. Pulau Seribu, Jepara, Situbondo and SpermondeArchipelago). The results showed that humpback grouper population has a high haplotype and nucleotide diversity. However, high geneticdiversity and polymorphisms could not reveal population fragmentation (Φ stt = 0.000). It is suggested that high gene flow rather thanpopulation sub structuring was occurred. High level genetic diversity and polymorphisms are vital related to adaptive potential toenvironmental alteration.

scholarly journals Going with the flow: analysis of population structure reveals high gene flow shaping invasion pattern and inducing range expansion of Mikania micrantha in Asia

2020 ◽  
Vol 125 (7) ◽  
pp. 1113-1126
Author(s):  
Achyut Kumar Banerjee ◽  
Zhuangwei Hou ◽  
Yuting Lin ◽  
Wentao Lan ◽  
Fengxiao Tan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Distance ◽  
Range Expansion ◽  
Mikania Micrantha ◽  
High Gene Flow ◽  
Genetic Pattern ◽  
High Gene

Abstract Background and Aims Mikania micrantha, a climbing perennial weed of the family Asteraceae, is native to Latin America and is highly invasive in the tropical belt of Asia, Oceania and Australia. This study was framed to investigate the population structure of M. micrantha at a large spatial scale in Asia and to identify how introduction history, evolutionary forces and landscape features influenced the genetic pattern of the species in this region. Methods We assessed the genetic diversity and structure of 1052 individuals from 46 populations for 12 microsatellite loci. The spatial pattern of genetic variation was investigated by estimating the relationship between genetic distance and geographical, climatic and landscape resistances hypothesized to influence gene flow between populations. Key Results We found high genetic diversity of M. micrantha in this region, as compared with the genetic diversity parameters of other invasive species. Spatial and non-spatial clustering algorithms identified the presence of multiple genetic clusters and admixture between populations. Most of the populations showed heterozygote deficiency, primarily due to inbreeding, and the founder populations showed evidence of a genetic bottleneck. Persistent gene flow throughout the invasive range caused low genetic differentiation among populations and provided beneficial genetic variation to the marginal populations in a heterogeneous environment. Environmental suitability was found to buffer the detrimental effects of inbreeding at the leading edge of range expansion. Both linear and non-linear regression models demonstrated a weak relationship between genetic distance and geographical distance, as well as bioclimatic variables and environmental resistance surfaces. Conclusions These findings provide evidence that extensive gene flow and admixture between populations have influenced the current genetic pattern of M. micrantha in this region. High gene flow across the invaded landscape may facilitate adaptation, establishment and long-term persistence of the population, thereby indicating the range expansion ability of the species.

Genetic diversity and biogeography of the boab Adansonia gregorii (Malvaceae: Bombacoideae)

2014 ◽  
Vol 62 (2) ◽  
pp. 164 ◽  
Author(s):  
Karen L. Bell ◽  
Haripriya Rangan ◽  
Rachael Fowler ◽  
Christian A. Kull ◽  
J. D. Pettigrew ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Population Bottleneck ◽  
Geographic Structure ◽  
Significant Gene ◽  
Spatial Principal Components ◽  
High Gene ◽  
Components Analysis ◽  
The Last Glacial Maximum ◽  
The Last Glacial

The Kimberley region of Western Australia is recognised for its high biodiversity and many endemic species, including the charismatic boab tree, Adansonia gregorii F.Muell. (Malvaceae: Bombacoideae). In order to assess the effects of biogeographic barriers on A. gregorii, we examined the genetic diversity and population structure of the tree species across its range in the Kimberley and adjacent areas to the east. Genetic variation at six microsatellite loci in 220 individuals from the entire species range was examined. Five weakly divergent populations, separated by west–east and coast–inland divides, were distinguished using spatial principal components analysis. However, the predominant pattern was low geographic structure and high gene flow. Coalescent analysis detected a population bottleneck and significant gene flow across these inferred biogeographic divides. Climate cycles and coastline changes following the last glacial maximum are implicated in decreases in ancient A. gregorii population size. Of all the potential gene flow vectors, various macropod species and humans are the most likely.

scholarly journals Genetic Diversity among Cowpea (Vigna unguiculata (L.) Walp.) Landraces Suggests Central Mozambique as an Important Hotspot of Variation

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1893
Author(s):  
Ana Maria Figueira Gomes ◽  
David Draper ◽  
Pedro Talhinhas ◽  
Paula Batista Santos ◽  
Fernanda Simões ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Vigna Unguiculata ◽  
African Countries ◽  
High Genetic Diversity ◽  
Ecological Zones ◽  
Nuclear Microsatellite ◽  
Tropical Areas ◽  
Other World ◽  
High Level

Cowpea is a multiple-purpose drought-tolerant leguminous pulse crop grown in several dry tropical areas. Its domestication center is thought to be East or West Africa, where a high level of genetic diversity is apparently still found. However, detailed genetic information is lacking in many African countries, limiting the success of breeding programs. In this work, we assessed the genetic variation and gene flow in 59 Vigna unguiculata (cowpea) accessions from 10 landraces spanning across six agro-ecological zones of Mozambique, based on nuclear microsatellite markers. The results revealed the existence of high genetic diversity between the landraces, even in comparison to other world regions. Four genetic groups were found, with no specific geographic pattern, suggesting the presence of gene flow between landraces. In comparison, the two commercial varieties had lower values of genetic diversity, although still close to the ones found in local landraces. The high genetic diversity found in Mozambique sustains the importance of local genetic resources and farm protection to enhance genetic diversity in modern varieties of cowpea worldwide.

Genetic diversity and population structure of wild pear (Pyrus pyraster (L.) Burgsd.) in Poland

2014 ◽  
Vol 10 (1) ◽  
Author(s):  
Łukasz Wolko ◽  
Jan Bocianowski ◽  
Wojciech Antkowiak ◽  
Ryszard Słomski
Keyword(s):  
Gene Flow ◽  
Population Diversity ◽  
Molecular Characteristics ◽  
Interspecies Hybridization ◽  
Geographical Distances ◽  
Ssr Loci ◽  
High Gene ◽  
The Mean ◽  
High Level ◽  
Amova Analysis

AbstractIn order to provide molecular characteristics of wild pear (P. pyraster) resources, six populations (192 accessions) from different regions of Poland were investigated with 17 SSR loci. Each of the SSR loci used was polymorphic, with a mean of 19.5 alleles per locus and a mean PIC of 0.806. Both the high heterozygosity (Ho = 0.751) and low Fis (0.007) indicated that the wild pear populations maintain a relatively high level of diversity, while the mean Findex of 0.039 and the number of migrants per generation (Nm = 6.996) revealed a high gene flow and weak inter-population differentiation. AMOVA analysis located polymorphisms mainly within populations (96%). Genetic relations between populations did not show correlations with geographical distances. The dispersal influence of gene flow could be the reason of the disrupted relationship within populations and the low interpopulation differentiation. We did not find any evidence to support the hypothesis about influence of interspecies hybridization with pear cultivars on the level of wild pear population diversity.

scholarly journals Effects of Colonization Processes on Genetic Diversity: Differences Between Annual Plants and Tree Species

Genetics ◽  
2000 ◽  
Vol 154 (3) ◽  
pp. 1309-1321 ◽  
Author(s):  
Frédéric Austerlitz ◽  
Stéphanie Mariette ◽  
Nathalie Machon ◽  
Pierre-Henri Gouyon ◽  
Bernard Godelle
Keyword(s):  
Genetic Diversity ◽  
Life Cycle ◽  
Gene Flow ◽  
Tree Species ◽  
Population Diversity ◽  
Pollen Flow ◽  
Nuclear Genes ◽  
Annual Plants ◽  
High Level ◽  
The Impact

Abstract Tree species are striking for their high within-population diversity and low among-population differentiation for nuclear genes. In contrast, annual plants show much more differentiation for nuclear genes but much less diversity than trees. The usual explanation for this difference is that pollen flow, and therefore gene flow, is much higher for trees. This explanation is problematic because it relies on equilibrium hypotheses. Because trees have very recently recolonized temperate areas, they have experienced many foundation events, which usually reduce within-population diversity and increase differentiation. Only extremely high levels of gene flow could counterbalance these successive founder effects. We develop a model to study the impact of life cycle of forest trees, in particular of the length of their juvenile phase, on genetic diversity and differentiation during the glacial period and the following colonization period. We show that both a reasonably high level of pollen flow and the life-cycle characteristics of trees are needed to explain the observed structure of genetic diversity. We also show that gene flow and life cycle both have an impact on maternally inherited cytoplasmic genes, which are characterized both in trees and annual species by much less diversity and much more differentiation than nuclear genes.

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.

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