scholarly journals Adaptive divergence in resistance to herbivores inDatura stramonium

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1411 ◽  
Author(s):  
Guillermo Castillo ◽  
Pedro L. Valverde ◽  
Laura L. Cruz ◽  
Johnattan Hernández-Cumplido ◽  
Guadalupe Andraca-Gómez ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Genetic Drift ◽  
Datura Stramonium ◽  
Adaptive Divergence ◽  
Restricted Gene Flow ◽  
Trichome Density ◽  
Phenotypic Differentiation ◽  
Phenotypic Resistance ◽  
Resistance Traits

Defensive traits exhibited by plants vary widely across populations. Heritable phenotypic differentiation is likely to be produced by genetic drift and spatially restricted gene flow between populations. However, spatially variable selection exerted by herbivores may also give rise to differences among populations. To explore to what extent these factors promote the among-population differentiation of plant resistance of 13 populations ofDatura stramonium, we compared the degree of phenotypic differentiation (PST) of leaf resistance traits (trichome density, atropine and scopolamine concentration) against neutral genetic differentiation (FST) at microsatellite loci. Results showed that phenotypic differentiation in defensive traits among-population is not consistent with divergence promoted by genetic drift and restricted gene flow alone. Phenotypic differentiation in scopolamine concentration was significantly higher thanFSTacross the range of trait heritability values. In contrast, genetic differentiation in trichome density was different fromFSTonly when heritability was very low. On the other hand, differentiation in atropine concentration differed from the neutral expectation when heritability was less than or equal to 0.3. In addition, we did not find a significant correlation between pair-wise neutral genetic distances and distances of phenotypic resistance traits. Our findings reinforce previous evidence that divergent natural selection exerted by herbivores has promoted the among-population phenotypic differentiation of defensive traits inD. stramonium.

scholarly journals Genetic differentiation and restricted gene flow in rice landraces from Yunnan, China: effects of isolation-by-distance and isolation-by-environment

2020 ◽  
Author(s):  
Di Cui ◽  
Cuifeng Tang ◽  
Hongfeng Lu ◽  
Jinmei Li ◽  
Xiaoding Ma ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Target Genes ◽  
Isolation By Distance ◽  
Local Environment ◽  
Adaptive Divergence ◽  
Restricted Gene Flow ◽  
Geographical Isolation ◽  
Rice Landraces ◽  
Isolation By Environment

Abstract Background Understanding and identifying the factors responsible for genetic differentiation is of fundamental importance for efficient utilization and conservation of traditional rice landraces. In this study, we examined the spatial genetic differentiation of 594 individuals sampled from 28 locations in Yunnan Province, China, covering a wide geographic distribution and diverse growing conditions. All 594 accessions were studied using ten unlinked target genes and 48 microsatellite loci, and the representative 108 accessions from the whole collection were sampled for resequencing. Results The genetic diversity of rice landraces was quite different geographically and exhibited a geographical decline from south to north in Yunnan, China. Population structure revealed that the rice landraces could be clearly differentiated into japonica and indica groups, respectively. In each group, the rice accessions could be further differentiated corresponded to their geographic locations, including three subgroups from northern, southern and middle locations. We found more obvious internal geographic structure in the japonica group than in the indica group. In the japonica group, we found that genetic and phenotypic differentiation were strongly related to geographical distance, suggesting a pattern of isolation by distance (IBD); this relationship remained highly significant when we controlled for environmental effects, where the likelihood of gene flow is inversely proportional to the distance between locations. Moreover, the gene flow also followed patterns of isolation by environment (IBE) whereby gene flow rates are higher in similar environments. We detected 314 and 216 regions had been differentially selected between Jap-N and Jap-S, Ind-N and Ind-S, respectively, and thus referred to as selection signatures for different geographic subgroups. We also observed a number of significant and interesting associations between loci and environmental factors, which implies adaptation to local environment. Conclusion Our findings highlight the influence of geographical isolation and environmental heterogeneity on the pattern of the gene flow, and demonstrate that both geographical isolation and environment drives adaptive divergence play dominant roles in the genetic differentiation of the rice landraces in Yunnan, China as a result of limited dispersal.

scholarly journals Genetic differentiation and restricted gene flow in rice landraces from Yunnan, China: effects of isolation-by-distance and isolation-by-environment

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Di Cui ◽  
Cuifeng Tang ◽  
Hongfeng Lu ◽  
Jinmei Li ◽  
Xiaoding Ma ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Target Genes ◽  
Isolation By Distance ◽  
Local Environment ◽  
Adaptive Divergence ◽  
Restricted Gene Flow ◽  
Geographical Isolation ◽  
Rice Landraces ◽  
Isolation By Environment

Abstract Background Understanding and identifying the factors responsible for genetic differentiation is of fundamental importance for efficient utilization and conservation of traditional rice landraces. In this study, we examined the spatial genetic differentiation of 594 individuals sampled from 28 locations in Yunnan Province, China, covering a wide geographic distribution and diverse growing conditions. All 594 accessions were studied using ten unlinked target genes and 48 microsatellite loci, and the representative 108 accessions from the whole collection were sampled for resequencing. Results The genetic diversity of rice landraces was quite different geographically and exhibited a geographical decline from south to north in Yunnan, China. Population structure revealed that the rice landraces could be clearly differentiated into japonica and indica groups, respectively. In each group, the rice accessions could be further differentiated corresponded to their geographic locations, including three subgroups from northern, southern and middle locations. We found more obvious internal geographic structure in the japonica group than in the indica group. In the japonica group, we found that genetic and phenotypic differentiation were strongly related to geographical distance, suggesting a pattern of isolation by distance (IBD); this relationship remained highly significant when we controlled for environmental effects, where the likelihood of gene flow is inversely proportional to the distance between locations. Moreover, the gene flow also followed patterns of isolation by environment (IBE) whereby gene flow rates are higher in similar environments. We detected 314 and 216 regions had been differentially selected between Jap-N and Jap-S, Ind-N and Ind-S, respectively, and thus referred to as selection signatures for different geographic subgroups. We also observed a number of significant and interesting associations between loci and environmental factors, which implies adaptation to local environment. Conclusions Our findings highlight the influence of geographical isolation and environmental heterogeneity on the pattern of the gene flow, and demonstrate that both geographical isolation and environment drives adaptive divergence play dominant roles in the genetic differentiation of the rice landraces in Yunnan, China as a result of limited dispersal.

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.

Elevational speciation in action? Restricted gene flow associated with adaptive divergence across an altitudinal gradient

2015 ◽  
Vol 29 (2) ◽  
pp. 241-252 ◽  
Author(s):  
W. C. Funk ◽  
M. A. Murphy ◽  
K. L. Hoke ◽  
E. Muths ◽  
S. M. Amburgey ◽  
...  
Keyword(s):  
Gene Flow ◽  
Altitudinal Gradient ◽  
Adaptive Divergence ◽  
Restricted Gene Flow

scholarly journals Plant speciation in continental island floras as exemplified by Nigella in the Aegean Archipelago

2008 ◽  
Vol 363 (1506) ◽  
pp. 3083-3096 ◽  
Author(s):  
Hans Peter Comes ◽  
Andreas Tribsch ◽  
Christiane Bittkau
Keyword(s):  
Gene Flow ◽  
Continental Shelf ◽  
Genetic Drift ◽  
Spatial Scales ◽  
Population Level ◽  
Minor Role ◽  
Restricted Gene Flow ◽  
Sea Levels ◽  
Rising Sea Levels ◽  
A Minor

Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of geographical isolation on non-adaptive radiation and allopatric speciation brought about by genetic drift. The Aegean Archipelago forms a highly fragmented complex of mostly continental shelf islands that have become disconnected from each other and the mainland in relatively recent geological times ( ca <5.2 Ma). These ecologically fairly homogenous islands thus provide a suitable biogeographic context for assessing the relative influences of past range fragmentation, colonization, gene flow and drift on taxon diversification. Indeed, recent molecular biogeographic studies on the Aegean Nigella arvensis complex, combining phylogenetic, phylogeographic and population level approaches, exemplify the importance of allopatry and genetic drift coupled with restricted gene flow in driving plant speciation in this continental archipelago at different temporal and spatial scales. While the recent (Late Pleistocene) radiation of Aegean Nigella , as well as possible instances of incipient speciation (in the Cyclades), is shown to be strongly conditioned by (palaeo)geographic factors (including changes in sea level), shifts in breeding system (selfing) and associated isolating mechanisms have also contributed to this radiation. By contrast, founder event speciation has probably played only a minor role, perhaps reflecting a migratory situation typical for continental archipelagos characterized by niche pre-emption because of a long established resident flora. Overall, surveys of neutral molecular markers in Aegean Nigella have so far revealed population genetic processes that conform remarkably well to predictions raised by genetic drift theory. The challenge is now to gain more direct insights into the relative importance of the role of genetic drift, as opposed to natural selection, in the phenotypic and reproductive divergence among these Aegean plant species.

Broad-ranging low genetic diversity among populations of the yellow finger marsh crab Sesarma rectum Randall, 1840 (Sesarmidae) revealed by DNA barcode

Crustaceana ◽  
2017 ◽  
Vol 90 (7-10) ◽  
pp. 845-864
Author(s):  
Raquel C. Buranelli ◽  
Fernando L. Mantelatto
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Isolation By Distance ◽  
Dna Barcode ◽  
Population Expansion ◽  
Haplotype Network ◽  
Sudden Expansion ◽  
Restricted Gene Flow ◽  
Western Atlantic

Population genetic studies on marine taxa, specifically in the field of phylogeography, have revealed distinct levels of genetic differentiation in widely distributed species, even though they present long planktonic larval development. A set of factors have been identified as acting on gene flow between marine populations, including physical or physiological barriers, isolation by distance, larval behaviour, and geological and demographic events. In this way, the aim of this study was to analyse the genetic variability among populations of the crab speciesSesarma rectumRandall, 1840 along the western Atlantic in order to check the levels of genetic diversity and differentiation among populations. To achieve this purpose, mtDNA cytochrome-coxidase subunit I (COI) (DNA-barcode marker) data were used to compute a haplotype network and a Bayesian analysis for genetic differentiation, to calculate an Analysis of Molecular Variance (AMOVA), and haplotype and nucleotide diversities. Neutrality tests (Tajima’sDand Fu’s ) were accessed, as well as pairwise mismatch distribution under the sudden expansion model. We found sharing of haplotypes among populations ofS. rectumalong its range of distribution and no significant indication for restricted gene flow between populations separately over 6000 km, supporting the hypothesis of a high dispersive capacity, and/or the absence of strong selective gradients along the distribution. Nevertheless, some results indicated population structure suggesting the presence of two genetic sources (i.e., groups or lineages), probably interpreted as a result of a very recent bottleneck effect due to habitat losses, followed by the beginning of a population expansion.

scholarly journals Adaptive divergence despite strong genetic drift: genomic analysis of the evolutionary mechanisms causing genetic differentiation in the island fox (Urocyon littoralis)

2016 ◽  
Vol 25 (10) ◽  
pp. 2176-2194 ◽  
Author(s):  
W. Chris Funk ◽  
Robert E. Lovich ◽  
Paul A. Hohenlohe ◽  
Courtney A. Hofman ◽  
Scott A. Morrison ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Genetic Drift ◽  
Genomic Analysis ◽  
Adaptive Divergence ◽  
Evolutionary Mechanisms ◽  
Island Fox ◽  
Urocyon Littoralis
Sign in / Sign up

Export Citation Format

Share Document