The phylogeography of Vellozia auriculata (Velloziaceae) supports low zygotic gene flow and local population persistence in the campo rupestre, a Neotropical OCBIL

2019 ◽  
Vol 191 (3) ◽  
pp. 381-398 ◽  
Author(s):  
Cecilia F Fiorini ◽  
Marina Dutra Miranda ◽  
Viviane Silva-Pereira ◽  
Ariane Raquel Barbosa ◽  
Ubirajara De Oliveira ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Local Population ◽  
Campo Rupestre ◽  
Conservation Practice ◽  
Local Survival ◽  
Inter Simple Sequence Repeats ◽  
Zygotic Gene ◽  
Simple Sequence

Abstract The campo rupestre is a Neotropical azonal vegetation. Its disjoint distribution and the fact that it is an old climatic buffered infertile landscape (OCBIL) have been associated with the high diversity and endemism observed in this environment. Here, we tested whether a micro-endemic species from campo rupestre shows: (1) limited zygotic gene flow; (2) lower gametic than zygotic gene flow structure; (3) substrate-driven genetic structure and (4) no evidence of Pleistocene local extinction or recolonization. By sequencing intergenic plastid regions, phenotyping inter simple sequence repeats (ISSR) and modelling present and past species suitability distributions for Vellozia auriculata we conclude that (1) zygotic gene flow is limited; (2) gametic gene flow is recurrent, but limited by elevation and distance; (3) there is no support for genetic structure driven by substrate and (4) Pleistocene climatic changes did not restrict the species to refugia, with local persistence. As long-term gene flow restrictions may lead to differentiation and speciation, our data helps to corroborate that the campo rupestre is both a cradle (due to low zygotic gene flow, prolonged isolation and consequent differentiation) and a lineage museum (due to local survival during climate oscillations). We highlight two distinct evolutionarily significant units (ESU), providing information for better conservation practice.

scholarly journals Musa sp. paradisiaca Cultivar Gopi and Clonal fidelity Assessment using ISSR Marker

2019 ◽  
Vol 29 (2) ◽  
pp. 175-184
Author(s):  
Rabindra Kumar Sinha ◽  
Puja Rani Saha ◽  
Bibhash Nath ◽  
H. Reshmi Singha ◽  
Anath Bandhu Das ◽  
...  
Keyword(s):  
Shoot Multiplication ◽  
Shoot Elongation ◽  
High Rate ◽  
Clonal Fidelity ◽  
Musa Sp ◽  
Inter Simple Sequence Repeats ◽  
Fidelity Assessment ◽  
Simple Sequence

Attempt was made towards optimizing an in vitro shoot multiplication of banana cultivar Gopi with subsequent assessment of genetic stability. Experiments on enhanced shoot multiplication were conducted in MS fortified with BAP, Kn and 2-iP (4 mg/l) for a period of 8 weeks. Administration of exogenous root inducing growth regulator was eliminated to reduce culture investment and economy. Treatment with BAP supplemented medium proved to be optimum for shoot multiplication whereas 2-iP produced satisfactory results for shoot elongation. Long term incubation in all the treatments had been favorable for developing efficient root system. Hardening of in vitro grown plantlets showed high rate of survival (95%) upon transfer to potted soil. Assessment of clonal fidelity through inter simple sequence repeats (ISSR) analysis revealed 100% uniformity.

Inter-simple sequence repeat (ISSR) and morphological variation in the western North American range of Chrysosplenium tetrandrum (Saxifragaceae)

Botany ◽  
2009 ◽  
Vol 87 (8) ◽  
pp. 780-790 ◽  
Author(s):  
Nicholas D. Levsen ◽  
Mark E. Mort
Keyword(s):  
Genetic Differentiation ◽  
North American ◽  
Glacial Refugia ◽  
Inter Simple Sequence Repeat ◽  
Population History ◽  
Inter Simple Sequence Repeats ◽  
Low Levels ◽  
Simple Sequence ◽  
Recent Bottleneck

The herbaceous perennial Chrysosplenium tetrandrum (Lund ex Malmgr.) Th. Fr. (Saxifragaceae) is a self-pollinating, circumpolar species with a broad latitudinal distribution and a disjunct North American range. The southernmost populations are isolated in the Rocky Mountains of Colorado and Montana, distantly separated from elements of the main range, which is largely coincident with known glacial refugia (e.g., Beringia) and recently deglaciated regions. We employed analyses of inter-simple sequence repeats (ISSRs) and morphology to determine patterns of variation within the western North American range of C. tetrandrum and test hypotheses of glacial population history and reproductive strategy. Analyses revealed very low estimates of range-wide genetic differentiation (θII = 0.085) and diversity (HS = 0.077, HT = 0.084), which are similar to levels found in other arctic plant species and have been primarily attributed to recent population establishment. Low levels of genetic differentiation among populations of Alaska (θII = 0.072), British Columbia (θII = 0.088), and Washington (θII = 0.058) suggest recent bottleneck or range expansion events. Both the Colorado and Alaska regions showed strong differentiation from each of the other regions, suggesting long-term isolation. The non-association between morphological and genetic variation indicates the effects of phenotypic plasticity or sexual reproduction.

scholarly journals Genetic diversity and phenetic relationships of five Trifolium L. species (Fabaceae) by inter simple sequence repeats markers

2016 ◽  
Vol 23 (2) ◽  
pp. 167-173
Author(s):  
Yourang Hwang ◽  
Man Kyu Huh
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Simple Sequence Repeats ◽  
Issr Markers ◽  
Phenetic Relationships ◽  
Inter Simple Sequence Repeats ◽  
Total Genetic Diversity ◽  
Plant Taxon ◽  
Simple Sequence

Five species of Trifolium L. (T. repens L., T. pretense L., T. hybridum L., T. campestre Schreb., and T. dubium Sibth.) were analyzed used to evaluate the genetic diversity and their phenetic relationships using inter-simple sequence repeats (ISSR) markers. Overall, T. pratense exhibited higher variation than other species. 114 amplicons were produced by ISSR markers, of which 77 (67.5%) bands were polymorphic. T. dubium showed the low genetic variation. Total genetic diversity values (HT) varied between 0.333 and 0.487, for an average over all polymorphic loci of 0.282. On a perlocus basis, the proportion of total genetic variation due to differences among species (GST) was 0.380. This indicated that about 38.0% of the total variation was among species. The estimate of gene flow, based on GST, was very low among species of genus Trifolium (Nm = 0.816). An assessment of the proportion of diversity present within species, HPOP/HSP, indicated that about 95.8% the total genetic diversity was within species. T. pratense and T. hybridum were grouped together and this clade was sister with T. repens. Two remainder species with yellow flowers were grouped together. Information on genetic diversity for Trifolium is valued for the management of germplasm and for evolving conservation strategies.Bangladesh J. Plant Taxon. 23(2): 167-173, 2016 (December)

Evidence of introgression in endemic frogs from the campo rupestre contradicts the reduced hybridization hypothesis

2020 ◽  
Author(s):  
Rafael F Magalhães ◽  
Priscila Lemes ◽  
Marcus Thadeu T Santos ◽  
Rafael M Mol ◽  
Elisa K S Ramos ◽  
...  
Keyword(s):  
Gene Flow ◽  
Introgressive Hybridization ◽  
Niche Overlap ◽  
Middle Pleistocene ◽  
Campo Rupestre ◽  
Haplotype Sharing ◽  
Environmental Niche ◽  
Climatic Fluctuation ◽  
Niche Modelling

Abstract The campo rupestre ecosystem is considered an old, climatically buffered, infertile landscape. As a consequence, long-term isolation is thought to have played an important role in the diversification of its biota. Here, we tested for hybridization between two endemic leaf frogs from the campo rupestre. We used sequence markers and coalescent models to verify haplotype sharing between the species, to test the existence and direction of gene flow, and to reconstruct the spatiotemporal dynamics of gene flow. Additionally, ecological niche modelling (ENM) was used to assess for potential co-occurrence by overlapping the climatic niche of these species since the middle Pleistocene. We found haplotype sharing and/or lack of differentiation in four nuclear fragments, one of them associated with introgression. The coalescent models support introgressive hybridization unidirectionally from Pithecopus megacephalus to P. ayeaye, occurring ~300 kya. ENM corroborates this scenario, revealing areas of potential environmental niche overlap for the species at about 787 kya. These results contradict the expectation of reduced hybridization, while ENM suggests climatic fluctuation rather than stability for the two species. The reduced hybridization hypothesis needs to be further investigated because our results suggest that it may have unrealistic premises at least for animals.

Historic and current genetic population structure in two pond-dwelling macroinvertebrates in massively altered Australian woodland landscapes

2010 ◽  
Vol 61 (11) ◽  
pp. 1318 ◽  
Author(s):  
Hania Lada ◽  
Carla Neville ◽  
Briarna Lacey ◽  
Ralph Mac Nally ◽  
P. Sam Lake ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Agricultural Development ◽  
Molecular Genetic ◽  
Agricultural Landscapes ◽  
Genetic Population ◽  
High Dispersal ◽  
Forested Landscapes ◽  
High Gene

Aquatic ecosystems around the world have been massively altered through vegetation clearance and changed flow regimes accompanying agricultural development. Impacts may include disrupted dispersal for aquatic species. We investigated this in lentic (standing) waterbodies in agricultural and predominantly forested landscapes of the box-ironbark region of central Victoria, Australia. We hypothesised that higher representation in forested than agricultural landscapes (i.e. ‘forest-bias’) for a species may reflect an ability to disperse more easily through the former, resulting in lower genetic structure in forested than in agricultural landscapes. Conversely, ‘cosmopolitan’ species would show no difference in genetic structure between landscape types. Molecular genetic analyses of a forest-biased diving beetle, Necterosoma wollastoni, and a cosmopolitan waterboatman, Micronecta gracilis, revealed the following, for both species: (1) no evidence for long-term barriers to gene flow in the region, (2) lack of contemporary genetic differentiation over 30 000 km2 and (3) random distribution of related genotypes in space, implying that neither forest nor farmland inhibits their dispersal in a concerted fashion. Taken together, these results indicate very high gene flow and dispersal in the past and present for both these species. Massive landscape change may have little impact on movement patterns of lentic invertebrates that have evolved high dispersal capabilities.

Anthropologic Relationships among Prehistoric Northeastern Amerindians

1980 ◽  
Vol 1 (2) ◽  
pp. 145-159
Author(s):  
Edward F. Harris ◽  
Nicholas F. Bellantoni
Keyword(s):  
New York ◽  
Gene Flow ◽  
Material Culture ◽  
New England ◽  
Cultural Barriers ◽  
Group Differences ◽  
Phenetic Analysis ◽  
Trade Relationships ◽  
Good Agreement

Archaeologically defined inter-group differences in the Northeast subarea ate assessed with a phenetic analysis of published craniometric information. Spatial distinctions in the material culture are in good agreement with those defined by the cranial metrics. The fundamental dichotomy, between the Ontario Iroquois and the eastern grouping of New York and New England, suggests a long-term dissociation between these two groups relative to their ecologic adaptations, trade relationships, trait-list associations, and natural and cultural barriers to gene flow.

Population fragmentation causes inadequate gene flow and increases extinction risk

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Gene Flow ◽  
Extinction Risk ◽  
Random Mating ◽  
Large Population ◽  
Isolated Population ◽  
Population Fragmentation ◽  
Single Population ◽  
Total Size ◽  
Limited Gene Flow

Most species now have fragmented distributions, often with adverse genetic consequences. The genetic impacts of population fragmentation depend critically upon gene flow among fragments and their effective sizes. Fragmentation with cessation of gene flow is highly harmful in the long term, leading to greater inbreeding, increased loss of genetic diversity, decreased likelihood of evolutionary adaptation and elevated extinction risk, when compared to a single population of the same total size. The consequences of fragmentation with limited gene flow typically lie between those for a large population with random mating and isolated population fragments with no gene flow.

scholarly journals Prediction of Genetic Contributions and Generation Intervals in Populations With Overlapping Generations Under Selection

Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1197-1210 ◽  
Author(s):  
Piter Bijma ◽  
John A Woolliams
Keyword(s):  
Gene Flow ◽  
Overlapping Generations ◽  
Selective Advantage ◽  
Turnover Time ◽  
Breeding Value ◽  
Age Classes ◽  
Generation Interval ◽  
Young Parents ◽  
Genetic Contributions

Abstract A method to predict long-term genetic contributions of ancestors to future generations is studied in detail for a population with overlapping generations under mass or sib index selection. An existing method provides insight into the mechanisms determining the flow of genes through selected populations, and takes account of selection by modeling the long-term genetic contribution as a linear regression on breeding value. Total genetic contributions of age classes are modeled using a modified gene flow approach and long-term predictions are obtained assuming equilibrium genetic parameters. Generation interval was defined as the time in which genetic contributions sum to unity, which is equal to the turnover time of genes. Accurate predictions of long-term genetic contributions of individual animals, as well as total contributions of age classes were obtained. Due to selection, offspring of young parents had an above-average breeding value. Long-term genetic contributions of youngest age classes were therefore higher than expected from the age class distribution of parents, and generation interval was shorter than the average age of parents at birth of their offspring. Due to an increased selective advantage of offspring of young parents, generation interval decreased with increasing heritability and selection intensity. The method was compared to conventional gene flow and showed more accurate predictions of long-term genetic contributions.

scholarly journals Hierarchical Analysis of Genetic Structure in Native Fire Ant Populations: Results From Three Classes of Molecular Markers

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 643-655 ◽  
Author(s):  
Kenneth G Ross ◽  
Michael J B Krieger ◽  
D DeWayne Shoemaker ◽  
Edward L Vargo ◽  
Laurent Keller
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Solenopsis Invicta ◽  
Large Scale ◽  
Fire Ant ◽  
Nuclear Markers ◽  
Social Forms ◽  
Native Populations ◽  
Nest Level ◽  
Nuclear Differentiation

We describe genetic structure at various scales in native populations of the fire ant Solenopsis invicta using two classes of nuclear markers, allozymes and microsatellites, and markers of the mitochondrial genome. Strong structure was found at the nest level in both the monogyne (single queen) and polygyne (multiple queen) social forms using allozymes. Weak but significant microgeographic structure was detected above the nest level in polygyne populations but not in monogyne populations using both classes of nuclear markers. Pronounced mitochondrial DNA (mtDNA) differentiation was evident also at this level in the polygyne form only. These microgeographic patterns are expected because polygyny in ants is associated with restricted local gene flow due mainly to limited vagility of queens. Weak but significant nuclear differentiation was detected between sympatric social forms, and strong mtDNA differentiation also was found at this level. Thus, queens of each form seem unable to establish themselves in nests of the alternate type, and some degree of assortative mating by form may exist as well. Strong differentiation was found between the two study regions usinga all three sets of markers. Phylogeographic analyses of the mtDNA suggest that recent limitations on gene flow rather than longstanding barriers to dispersal are responsible for this large-scale structure.

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