Impact of Gene Flow and Introgression on the Range Wide Genetic Structure of Quercus robur (L.) in Europe

As for most other temperate broadleaved tree species, large-scale genetic inventories of pedunculate oak (Quercus robur L.) have focused on the plastidial genome, which showed the impact of post-glacial recolonization and manmade seed transfer. However, how have pollen mediated gene flow and introgression impacted the large-scale genetic structure? To answer these questions, we did a genetic inventory on 1970 pedunculate oak trees from 197 locations in 13 European countries. All samples were screened with a targeted sequencing approach on a set of 381 polymorphic loci (356 nuclear SNPs, 3 nuclear InDels, 17 chloroplast SNPs, and 5 mitochondrial SNPs). In a former analysis with additional 1763 putative Quercus petraea trees screened for the same gene markers we obtained estimates on the species admixture of all pedunculate oak trees. We identified 13 plastidial haplotypes, which showed a strong spatial pattern with a highly significant autocorrelation up to a range of 1250 km. Significant spatial genetic structure up to 1250 km was also observed at the nuclear loci. However, the differentiation at the nuclear gene markers was much lower compared to the organelle gene markers. The matrix of genetic distances among locations was partially correlated between nuclear and organelle genomes. Bayesian clustering analysis revealed the best fit to the data for a sub-division into two gene pools. One gene pool is dominating the west and the other is the most abundant in the east. The western gene pool was significantly influenced by introgression from Quercus petraea in the past. In Germany, we identified a contact zone of pedunculate oaks with different introgression intensity, likely resulting from different historical levels of introgression in glacial refugia or during postglacial recolonization. The main directions of postglacial recolonization were south to north and south to northwest in West and Central Europe, and for the eastern haplotypes also east to west in Central Europe. By contrast, the pollen mediated gene flow and introgression from Q. petraea modified the large-scale structure at the nuclear gene markers with significant west–east direction.

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

Genetics ◽

10.1093/genetics/147.2.643 ◽

1997 ◽

Vol 147 (2) ◽

pp. 643-655 ◽

Cited By ~ 3

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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Geographic Structure of Mitochondrial and Nuclear Gene Polymorphisms in Australian Green Turtle Populations and Male-Biased Gene Flow

Genetics ◽

10.1093/genetics/147.4.1843 ◽

1997 ◽

Vol 147 (4) ◽

pp. 1843-1854 ◽

Cited By ~ 8

Author(s):

Nancy N FitzSimmons ◽

Craig Moritz ◽

Colin J Limpus ◽

Lisa Pope ◽

Robert Prince

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Green Turtle ◽

Nuclear Dna ◽

Nuclear Gene ◽

Chelonia Mydas ◽

Single Copy ◽

Microsatellite Data ◽

Ecological Data ◽

Infinite Allele Model

Abstract The genetic structure of green turtle (Chelonia mydas) rookeries located around the Australian coast was assessed by (1) comparing the structure found within and among geographic regions, (2) comparing microsatellite loci vs. restriction fragment length polymorphism analyses of anonymous single copy nuclear DNA (ascnDNA) loci, and (3) comparing the structure found at nuclear DNA markers to that of previously analyzed mitochondrial (mtDNA) control region sequences. Significant genetic structure was observed over all regions at both sets of nuclear markers, though the microsatellite data provided greater resolution in identifying significant genetic differences in pairwise tests between regions. Inferences about population structure and migration rates from the microsatellite data varied depending on whether statistics were based on the stepwise mutation or infinite allele model, with the latter being more congruent with geography. Estimated rates of gene flow were generally higher than expected for nuclear DNA (nDNA) in comparison to mtDNA, and this difference was most pronounced in comparisons between the northern and southern Great Barrier Reef (GBR). The genetic data combined with results from physical tagging studies indicate that the lack of nuclear gene divergence through the GBR is likely due to the migration of sGBR turtles through the courtship area of the nGBR population, rather than male-biased dispersal. This example highlights the value of combining comparative studies of molecular variation with ecological data to infer population processes.

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Long-term effects of drought on photosynthesis of adult oak trees [Quercus petraea (Matt.) Liebl. and Quercus robur L.] in a natural stand

New Phytologist ◽

10.1111/j.1469-8137.1993.tb03890.x ◽

1993 ◽

Vol 125 (2) ◽

pp. 381-389 ◽

Cited By ~ 114

Author(s):

DANIEL EPRON ◽

ERWIN DREYER

Keyword(s):

Quercus Robur ◽

Quercus Petraea ◽

Long Term Effects ◽

Natural Stand ◽

Oak Trees ◽

Effects Of Drought

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Population genetic structure of pedunculate oak (Quercus robur L.) in Belarus according to the analysis of chloroplast DNA

Journal of the Belarusian State University Biology ◽

10.33581/2521-1722-2021-3-59-70 ◽

2021 ◽

pp. 59-70

Author(s):

Vladimir E. Padutov

Keyword(s):

Genetic Structure ◽

Chloroplast Dna ◽

Population Genetic Structure ◽

Population Genetic ◽

Quercus Robur ◽

Phylogenetic Trees ◽

Rflp Analysis ◽

Pedunculate Oak ◽

Maximum Likelihood Methods ◽

The Republic

Pedunculate oak (Quercus robur L.) is one of the main forest forming species in the Republic of Belarus. Its population genetic structure was formed under the influence of various migration processes. Six chloroplast DNA loci (µdt1, µdt3, µdt4, µcd4, µcd5 and µkk4) were used for the genogeographic study. The material for the analysis was collected in 100 oak forest stands (2325 samples); 18 allelic variants were identified, which are grouped into 17 different combinations (haplotypes). Five of them are widespread (the proportion of occurrence varies from 7 to 48 %, totalling 85 %). The remaining 12 are rare (the proportion of occurrence varies from 1 to 3 %, totalling 15 %). Phylogenetic trees constructed using the nearest neighbour and maximum likelihood methods show the presence of two groups (branches) of haplotypes. One of it comprises 8 variants including 2 dominant haplotypes and the other comprises 9 variants including 3 dominant haplotypes. PCR-RFLP analysis of chloroplast DNA showed that the pedunculate oak in Belarus originates from the Balkan refugium. Haplotype No. 1 (µdt189, µdt3123, µdt4142, µcd494, µcd574, µkk4109) is found almost everywhere in Belarus with the exception of the southwest and northeast, while haplotype No. 8 (µdt189, µdt3121, µdt4142, µcd494, µcd574, µkk4109) is mainly localised in the southwest and northeast. Haplotypes No. 3 (µdt189, µdt3120, µdt4141, µcd494, µcd575, µkk4109) and No. 7 (µdt189, µdt3122, µdt4142, µcd494, µcd574, µkk4109) predominantly found in the west of the country. Haplotype No. 2 (µdt190, µdt3120, µdt4141, µcd495, µcd574, µkk4109) is typical for the southeast.

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Appreciation of tolerance at the impact of thermal stress on photosystem ii activity in the leaves of pedunculate oak (Quercus robur L.) trees of different ecological origin

Journal of Botany ◽

10.52240/1857-2367.2021.1(22).04 ◽

2021 ◽

Vol 13 (1(22)) ◽

pp. 13-20

Author(s):

Petru Cuza ◽

Keyword(s):

Thermal Stress ◽

Photosystem Ii ◽

Quercus Robur ◽

Central Area ◽

Extreme Weather Events ◽

Pedunculate Oak ◽

Adaptation Capacity ◽

Oak Trees ◽

Photosystem Ii Activity ◽

The Impact

Extreme weather events with high temperatures and strong sunlight have increased alarmingly in the last few decades, considerable affecting plant photosynthesis. In this study, the impact of thermal stress on photosystem II activity in the leaves of pedunculate oak trees (Quercus robur L.) of different ecological origin was assessed. Four days after the thermal shock application with a temperature of 50°C during 20, 40, 60 minutes, the processes of recovery on photosystem II activity in the leaves of the oak trees in the investigated provenances took place with different speed and fullness. The recovery of the functional state of photosystem II in the leaves of the trees showed that in the environmental conditions of the ,,Plaiul Fagului” reservation territory an advanced thermotolerance to the thermal stress action was specifi c for the origin from the north of the country (Edinet). The leaves of the trees of local and southern origin showed a low resistance to the thermal stress action. The advanced adaptation capacity, the high growth rate of the trees from the northern provenance suggest that the acorn harvested from the oaks of northern origin can be used for the works of extension of the afforestation areas in the central area of the Republic of Moldova.

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Oak Species Quercus robur L. and Quercus petraea Liebl. Identification Based on UHPLC-HRMS/MS Molecular Networks

Metabolites ◽

10.3390/metabo11100684 ◽

2021 ◽

Vol 11 (10) ◽

pp. 684

Author(s):

Gaëlle Buche ◽

Cyril Colas ◽

Laëtitia Fougère ◽

Emilie Destandau

Keyword(s):

Quercus Robur ◽

Quercus Petraea ◽

Molecular Network ◽

Molecular Networks ◽

Venn Diagram ◽

Pedunculate Oak ◽

Pure Species ◽

Wide Range ◽

Fragmentation Patterns ◽

The Individual

Two species of oak are dominant in French forests: pedunculate oak (Quercus robur L.) and sessile oak (Quercus petraea Liebl.). Their differentiation is not straightforward but is essential to better understand their respective molecular content in order to better valorize them. Thus, to improve oak species identification, an untargeted UHPLC-HRMS/MS method associated with a two-step data treatment was developed to analyze a wide range of specialized metabolites enabling the comparison of both species of oak extracts. Pooled extracts from sessile and pedunculate oaks, composed of extracts from several trees of pure species from various origins, were compared using first the Venn diagram, as a quick way to get an initial idea of how close the extracts are, and then using a molecular network to visualize, on the one hand, the ions shared between the two species and, on the other hand, the compounds specific to one species. The molecular network showed that the two species shared common clusters mainly representative of tannins derivatives and that each species has specific molecules with similar fragmentation patterns, associated in specific clusters. This methodology was then applied to compare these two pooled extracts to unknown individuals in order to determine the species. The Venn diagram allowed for the quick presumption of the species of the individual and then the species could be assigned more precisely with the molecular network, at the level of specific clusters. This method, developed for the first time, has several interests. First, it makes it possible to discriminate the species and to correctly assign the species of unknown samples. Moreover, it gave an overview of the metabolite composition of each sample to better target oak tree utilization and valorization.

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