scholarly journals Maintaining their genetic distance; limited gene flow between widely hybridising species of Geum with contrasting mating systems

2017 ◽  
Author(s):  
Crispin Y. Jordan ◽  
Konrad Lohse ◽  
Frances Turner ◽  
Marian Thomson ◽  
Karim Gharbi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Mating System ◽  
Draft Genome ◽  
Sympatric Populations ◽  
Species Classification ◽  
Interspecific Gene Flow ◽  
System Transition ◽  
Tentative Evidence ◽  
Limited Gene Flow

AbstractMating system transition from outcrossing to selfing frequently gives rise to sister lineages with contrasting outcrossing rates. The evolutionary fate of such lineages depends on the extent to which they exchange genes. We measured gene flow between outcrossing Geum rivale and selfing G. urbanum, two sister species derived by mating system transition, which frequently hybridise. A draft genome was generated for G. urbanum and used to develop dd-RAD data scorable in both species. Coalescent analysis of RAD data from allopatric populations indicated that the two species diverged 2-3 Mya, and that long term gene flow between them has been very low (M=0.04). G. rivale showed greater genetic diversity in sympatry than allopatry, but genetic divergence between species was no lower in sympatry than allopatry, providing little evidence for recent introgression. Clustering of genotypes revealed that, apart from four early generation hybrids, individuals in sympatric populations fell into two genetically distinct groups with <1% admixture that corresponded exactly to their morphological species classification. Although our data suggest limited gene flow, we observed joint segregation of two putatively introgressed SNPs in G. urbanum populations that was associated with significant morphological variation; this provides tentative evidence for rare introduction of novel genetic diversity by interspecific gene flow. Our results indicate that despite frequent hybridisation, genetic exchange between G. rivale and G. urbanum has been very limited throughout their evolutionary history.

Interspecific gene flow and an intermediate molecular profile of Dyckia julianae (Bromeliaceae), an endemic species from southern Brazil

2019 ◽  
Vol 192 (4) ◽  
pp. 675-690 ◽  
Author(s):  
Luiza D Hirsch ◽  
Camila M Zanella ◽  
Camila Aguiar-Melo ◽  
Laís M S Costa ◽  
Fernanda Bered
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
The Other ◽  
Hybrid Origin ◽  
Molecular Profile ◽  
Southern Brazil ◽  
Sympatric Populations ◽  
Interspecific Gene Flow ◽  
Viable Seeds ◽  
Origin Hypothesis

Abstract When related species are distributed in sympatric populations, hybridization may occur. Likewise, one or more of these species may have arisen through historical hybridization between taxa. Here, we aim to elucidate the occurrence of hybridization among three Dyckia spp. (Bromeliaceae) from southern Brazil. We used seven nuclear and six plastid microsatellite loci to assess patterns of genetic diversity, population structure and hybridization in the three species. Furthermore, we performed manual crosses between species to test compatibility and fertility. The results showed that Dyckia julianae has an intermediate molecular profile, low gene flow occurs between Dyckia hebdingii and Dyckia choristaminea and higher gene flow occurs between D. julianae and the other two species. Plastid microsatellites identified 12 haplotypes that are shared among the species. The manual crosses between D. julianae and the other two species produced viable seeds, but no crosses between D. hebdingii and D. choristaminea generated fruits. Our data suggest that the reproductive barrier between D. julianae and the other two species is permeable. Further investigation into the hybrid origin hypothesis of D. julianae should be undertaken, as well as the mechanisms involved in reproductive isolation between D. hebdingii and D. choristaminea.

scholarly journals Gene Flow in Phaseolus Beans and Its Role as a Plausible Driver of Ecological Fitness and Expansion of Cultigens

2021 ◽  
Vol 9 ◽  
Author(s):  
María Isabel Chacón-Sánchez ◽  
Jaime Martínez-Castillo ◽  
Jorge Duitama ◽  
Daniel G. Debouck
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Time Perspective ◽  
Lima Bean ◽  
Breeding Systems ◽  
Large Contribution ◽  
Interspecific Gene Flow ◽  
Ecological Fitness ◽  
Technological Advances ◽  
Evolutionary Force

The genus Phaseolus, native to the Americas, is composed of more than eighty wild species, five of which were domesticated in pre-Columbian times. Since the beginning of domestication events in this genus, ample opportunities for gene flow with wild relatives have existed. The present work reviews the extent of gene flow in the genus Phaseolus in primary and secondary areas of domestication with the aim of illustrating how this evolutionary force may have conditioned ecological fitness and the widespread adoption of cultigens. We focus on the biological bases of gene flow in the genus Phaseolus from a spatial and time perspective, the dynamics of wild-weedy-crop complexes in the common bean and the Lima bean, the two most important domesticated species of the genus, and the usefulness of genomic tools to detect inter and intraspecific introgression events. In this review we discuss the reproductive strategies of several Phaseolus species, the factors that may favor outcrossing rates and evidence suggesting that interspecific gene flow may increase ecological fitness of wild populations. We also show that wild-weedy-crop complexes generate genetic diversity over which farmers are able to select and expand their cultigens outside primary areas of domestication. Ultimately, we argue that more studies are needed on the reproductive biology of the genus Phaseolus since for most species breeding systems are largely unknown. We also argue that there is an urgent need to preserve wild-weedy-crop complexes and characterize the genetic diversity generated by them, in particular the genome-wide effects of introgressions and their value for breeding programs. Recent technological advances in genomics, coupled with agronomic characterizations, may make a large contribution.

scholarly journals Genomic signals of admixture and reinforcement between two closely related species of European sepsid flies

2020 ◽  
Author(s):  
Athene Giesen ◽  
Wolf U. Blanckenhorn ◽  
Martin A. Schäfer ◽  
Kentaro K. Shimizu ◽  
Rie Shimizu-Inatsugi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Dna Sequence ◽  
Species Boundaries ◽  
Adaptive Divergence ◽  
Sympatric Populations ◽  
Interspecific Gene Flow ◽  
Natural Systems ◽  
Sequence Identity ◽  
Interspecific Differences ◽  
Genome Wide

ABSTRACTInterspecific gene flow by hybridization may weaken species barriers and adaptive divergence, but can also initiate reinforcement of reproductive isolation trough natural and sexual selection. The extent of interspecific gene flow and its consequences for the initiation and maintenance of species barriers in natural systems remain poorly understood, however. To assess genome-wide patterns of gene flow between the two closely related European dung fly species Sepsis cynipsea and Sepsis neocynipsea (Diptera: Sepsidae), we tested for historical gene flow with the aid of ABBA-BABA test using whole-genome resequencing data from pooled DNA of male specimens originating from natural and laboratory populations. We contrasted genome-wide variation in DNA sequence differences between samples from sympatric populations of the two species in France and Switzerland with that of interspecific differences between pairs of samples involving allopatric populations from Estonia and Italy. In the French Cevennes, we detected a relative excess of DNA sequence identity, suggesting interspecific gene flow in sympatry. In contrast, at two sites in Switzerland, we observed a relative depletion of DNA sequence identity compatible with reinforcement of species boundaries in sympatry. Our results suggest that the species boundaries between S. cynipsea and S. neocynipsea in Europe depend on the eco-geographic context.

scholarly journals Increases in Genetic Diversity of Weedy Rice Associated with Ambient Temperatures and Limited Gene Flow

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 71
Author(s):  
Hua Kong ◽  
Zhi Wang ◽  
Jing-Yuan Guo ◽  
Qi-Yu Xia ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Weedy Rice ◽  
Global Pattern ◽  
Molecular Fingerprints ◽  
Ambient Temperatures ◽  
Late Season ◽  
Different Temperatures ◽  
Limited Gene Flow

Hypotheses regarding the association of increased species or genetic diversity with gradually warmer regions as a global pattern have been proposed, but no direct and solid experimental data are available to approve the association between plant genetic diversity and ambient temperatures. To test the diversity-temperature hypothesis, we studied genetic diversity and genetic differentiation of weedy rice (Oryza sativa f. spontanea) populations occurring naturally in early- and late-season rice fields that share nearly the same ecological conditions but with slightly different temperatures. Data collected from 10-year historical climatic records indicated a ~2 °C higher average air temperature in the late rice-cultivation seasons than in the early seasons. Results based on molecular fingerprints of 27 SSR (simple sequence repeat) loci showed a higher level of genetic diversity in the late-season weedy rice populations than in the early-season populations. In addition, a positive correlation was detected between the increased proportion of genetic diversity (ΔHe) and genetic differentiation among the weedy rice populations, suggesting limited gene flow. Therefore, we conclude from this study that increased genetic diversity in the late-season weedy rice populations is probably caused by the higher ambient temperatures. This finding provides evidence for the possible association between genetic diversity and ambient temperatures.

scholarly journals Genetic variation of Anisoptera costata Korth in Tan Phu tropical forest, Dinh Quan district, Dong Nai province

2021 ◽  
Vol 19 (2) ◽  
pp. 279-288
Author(s):  
Dang Phan Hien ◽  
Nguyen Minh Duc ◽  
Nguyen Phan Lan Hong ◽  
Bui Thi Tuyet Xuan ◽  
Vu Dinh Duy ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Tropical Forests ◽  
Mean Values ◽  
Genetic Lineages ◽  
Adult Trees ◽  
Lowland Forests ◽  
Limited Gene Flow ◽  
Over Exploitation

Anisoptera costata Korth, an endangered species is distributed in lowland tropical forests of southern Vietnam. Habitat loss and over-exploitation are the major reasons for threatening this species. Eight polymorphic microsatellite markers were used to analyze 64 adult trees from three A. costata populations in lowland tropical forests of Tan Phu, Dinh Quan district, Dong Nai Province in Southeast Vietnam to detect the effects of deforestation on gene flow and the differentiation among populations in lowland tropical forests. The results showed that all A. costata populations have the moderate levels of the genetic diversity within populations with mean values of observed and expected heterozygosities, 0.242 and 0.269, respectively, moderate genetic differentiation among A. costata populations (0.179), and indicating limited gene flow (Nm = 1.15). Analysis of molecular variance indicated high genetic variation within populations (64.68%) and indicating moderate genetic structure in A. costata in Tan Phu. Bayesian analysis detected two genetic lineages, cluster 1 including one population of Mieu Co Nam and cluster 2 including two populations, Thac Mai and Bau Nuoc. These results contribute understanding genetic diversity of A. costata in lowland forests of Southeastern Vietnam and will provide guidelines for conservation, management and resoration of the species.

scholarly journals Genomic signals of admixture and reinforcement between two closely related species of European sepsid flies

2021 ◽  
Author(s):  
Athene Giesen ◽  
Wolf Blanckenhorn ◽  
Martin Schäfer ◽  
Kentaro K. Shimizu ◽  
Rie Shimizu-Inatsugi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Dna Sequence ◽  
Species Boundaries ◽  
Adaptive Divergence ◽  
Sympatric Populations ◽  
Interspecific Gene Flow ◽  
Natural Systems ◽  
Sequence Identity ◽  
Interspecific Differences ◽  
Genome Wide

Interspecific gene flow by hybridization may weaken species barriers and adaptive divergence, but can also initiate reinforcement of reproductive isolation trough natural and sexual selection. The extent of interspecific gene flow and its consequences for the initiation and maintenance of species barriers in natural systems remain poorly understood, however. To assess genome-wide patterns of gene flow between the two closely related European dung fly species Sepsis cynipsea and Sepsis neocynipsea (Diptera: Sepsidae), we tested for historical gene flow with the aid of ABBA-BABA test using whole-genome resequencing data from pooled DNA of male specimens originating from natural and laboratory populations. We contrasted genome-wide variation in DNA sequence differences between samples from sympatric populations of the two species in France and Switzerland with that of interspecific differences between pairs of samples involving allopatric populations from Estonia and Italy. In the French Cevennes, we detected a relative excess of DNA sequence identity, suggesting interspecific gene flow in sympatry. In contrast, at two sites in Switzerland, we observed a relative depletion of DNA sequence identity compatible with reinforcement of species boundaries in sympatry. Our results suggest that the species boundaries between S. cynipsea and S. neocynipsea in Europe depend on the eco-geographic context.

scholarly journals Estimating the temporal and spatial extent of gene flow among sympatric lizard populations (genus Sceloporus) in the southern Mexican highlands

2014 ◽  
Author(s):  
Jared A Grummer ◽  
Martha L. Calderón ◽  
Adrián Nieto Montes-de Oca ◽  
Eric N Smith ◽  
Fausto Méndez-de la Cruz ◽  
...  
Keyword(s):  
Gene Flow ◽  
Ancestral Population ◽  
Secondary Contact ◽  
Sympatric Populations ◽  
Interspecific Gene Flow ◽  
Ancestral Gene ◽  
Mixed Support ◽  
Coalescent Simulations ◽  
Range Overlap ◽  
Analytical Approaches

Interspecific gene flow is pervasive throughout the tree of life. Although detecting gene flow between populations has been facilitated by new analytical approaches, determining the timing and geography of hybridization has remained difficult, particularly for historical gene flow. A geographically explicit phylogenetic approach is needed to determine the ancestral population overlap. In this study, we performed population genetic analyses, species delimitation, simulations, and a recently developed approach of species tree diffusion to infer the phylogeographic history, timing and geographic extent of gene flow in lizards of the Sceloporus spinosus group. The two species in this group, S. spinosus and S. horridus, are distributed in eastern and western portions of Mexico, respectively, but populations of these species are sympatric in the southern Mexican highlands. We generated data consisting of three mitochondrial genes and eight nuclear loci for 148 and 68 individuals, respectively. We delimited six lineages in this group, but found strong evidence of mito-nuclear discordance in sympatric populations of S. spinosus and S. horridus owing to mitochondrial introgression. We used coalescent simulations to differentiate ancestral gene flow from secondary contact, but found mixed support for these two models. Bayesian phylogeography indicated more than 60% range overlap between ancestral S. spinosus and S. horridus populations since the time of their divergence. Isolation-migration analyses, however, revealed near-zero levels of gene flow between these ancestral populations. Interpreting results from both simulations and empirical data indicate that despite a long history of sympatry among these two species, gene flow in this group has only recently occurred.

scholarly journals Genetic Structure and Diversity of Attalea vitrivir Populations in Brazilian Cerrado

2020 ◽  
Vol 12 (2) ◽  
pp. 177
Author(s):  
Bárbara Rayane Ramos Muniz Nassau ◽  
Lorena Ramos da Mata ◽  
Márcio de Carvalho Moretzsohn ◽  
Vânia Cristina Rennó Azevedo ◽  
Marcelo Mattos Cavallari ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Variability ◽  
Conservation Status ◽  
Wide Distribution ◽  
Palm Tree ◽  
High Genetic Diversity ◽  
Minas Gerais State ◽  
Limited Gene Flow ◽  
Genetic Structure And Diversity

The Babassu (Attalea sp.) is a native palm tree, belonging to the family Arecaceae, with a wide distribution in Brazil. The species Attalea vitrivir Zona occurs in the Northwest of Minas Gerais State and Southwest of Bahia State, where the Cerrado is the predominant biome. Babassu is an important native oil resource and one of the main extractive products in Brazil, besides contributing significantly to the economy of some Brazilian States. The results of an ongoing study of the conservation status and genetic diversity of populations of the palm A.vitrivir are presented. The distribution of A. vitrivir has been reduced by habitat fragmentation, resulting in two main regions of occurrence (northern and southern), with a large gap between them, being only one of them protected by a conservation unit. A total of 84 microsatellite primer pairs designed for Attalea speciosa were screened for polymorphism and transferability in A. vitrivir individuals and 21 transferable primer pairs were used to better understand the distribution of genetic variability, gene flow and conservation status of A. vitrivir populations.The genetic diversity estimates using these primers indicated high levels of genetic variation and showed that a higher variation was located within than among populations, probably due to reproductive isolation. The five populations evaluated were grouped into two distinct groups, coinciding with northern and southern regions. High genetic diversity within populations and high differentiation among both regions indicate limited gene flow. The northern unprotected populations presented high genetic variability and should also be considered for protection for the long term conservation of the species.

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