Measuring recent effective gene flow among large populations in Pinus sylvestris: Local pollen shedding does not preclude substantial long-distance pollen immigration

The estimation of recent gene flow rates among vast and often weakly genetically differentiated tree populations remains a great challenge. Yet, empirical information would help understanding the interaction between gene flow and local adaptation in present-day non-equilibrium forests. We investigate here recent gene flow rates between two large native Scots pine (Pinus sylvestris L.) populations in central Iberian Peninsula (Spain), which grow on contrasting edaphic conditions six kilometers apart from each other and show substantial quantitative trait divergence in common garden experiments. Using a sample of 1,200 adult and offspring chloroplast-microsatellite haplotypes and a Bayesian inference model, we estimated substantial male gametic gene flow rates (8 and 21%) between the two natural populations, and even greater estimated immigration rates (42 and 64%) from nearby plantations into the two natural populations. Our results suggest that local pollen shedding within large tree populations does not preclude long-distance pollen immigration from large external sources, supporting the role of gene flow as a homogenizing evolutionary force contributing to low molecular genetic differentiation among populations of widely distributed wind-pollinated species. Our results also indicate the high potential for reproductive connectivity in large fragmented populations of wind-pollinated trees, and draw attention to a potential scenario of adaptive genetic divergence in quantitative traits under high gene flow.

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Genomics of clinal local adaptation in Pinus sylvestris under continuous environmental and spatial genetic setting

10.1101/647412 ◽

2019 ◽

Cited By ~ 1

Author(s):

Jaakko S. Tyrmi ◽

Jaana Vuosku ◽

Juan J. Acosta ◽

Zhen Li ◽

Lieven Sterck ◽

...

Keyword(s):

Pinus Sylvestris ◽

Local Adaptation ◽

Large Scale ◽

Molecular Genetic ◽

Natural Populations ◽

Keystone Species ◽

Evolutionary Genetics ◽

Genomic Diversity ◽

Landscape Genomics ◽

Polygenic Adaptation

AbstractUnderstanding the consequences of local adaptation at the genomic diversity is a central goal in evolutionary genetics of natural populations. In species with large continuous geographical distributions the phenotypic signal of local adaptation is frequently clear, but the genetic background often remains elusive. We examined the patterns of genetic diversity in Pinus sylvestris, a keystone species in many Eurasian ecosystems with a huge distribution range and decades of forestry research showing that it is locally adapted to the vast range of environmental conditions. Making P. sylvestris an even more attractive subject of local adaptation study, population structure has been shown to be weak previously and in this study. However, little is known about the molecular genetic basis of adaptation, as the massive size of gymnosperm genomes has prevented large scale genomic surveys. We generated a both geographically and genomically extensive dataset using a targeted sequencing approach. By applying divergence-based and landscape genomics methods we found that several coding loci contribute to local adaptation. We also discovered a very large (ca. 300 Mbp) putative inversion with a signal of local adaptation, which to our knowledge is the first such discovery in conifers. Our results call for more detailed analysis of structural variation in relation to genomic basis of local adaptation, emphasize the lack of large effect loci contributing to local adaptation in the coding regions and thus point out to the need for more attention towards multi-locus analysis of polygenic adaptation.

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Molecular genetic variation in a widespread forest tree species Eucalyptus obliqua (Myrtaceae) on the island of Tasmania

Australian Journal of Botany ◽

10.1071/bt10315 ◽

2011 ◽

Vol 59 (3) ◽

pp. 226 ◽

Cited By ~ 28

Author(s):

Justin A. Bloomfield ◽

Paul Nevill ◽

Brad M. Potts ◽

René E. Vaillancourt ◽

Dorothy A. Steane

Keyword(s):

Genetic Variation ◽

Gene Flow ◽

Environmental Gradients ◽

Molecular Genetic ◽

Continuous Distribution ◽

Main Mode ◽

Chloroplast Microsatellite ◽

Eastern Australia ◽

Nuclear Microsatellite ◽

Microsatellite Diversity

Eucalyptus obliqua L’Hér. is widespread across south-eastern Australia. On the island of Tasmania it has a more-or-less continuous distribution across its range and it dominates much of the wet sclerophyll forest managed for forestry purposes. To understand better the distribution of genetic variation in these native forests we examined nuclear microsatellite diversity in 432 mature individuals from 20 populations of E. obliqua across Tasmania, including populations from each end of three locally steep environmental gradients. In addition, chloroplast microsatellite loci were assessed in 297 individuals across 31 populations. Nuclear microsatellite diversity values in E. obliqua were high (average HE = 0.80) and inbreeding coefficients low (average F = 0.02) within these populations. The degree of differentiation between populations was very low (FST = 0.015). No significant microsatellite differentiation could be found across three locally steep environmental gradients, even though there is significant genetic differentiation in quantitative traits. This suggests that the observed quantitative variation is maintained by natural selection. Population differentiation based on chloroplast haplotypes was high (GST = 0.69) compared with that based on nuclear microsatellites, suggesting that pollen-mediated gene flow is >150 times the level of seed-mediated gene flow in this animal-pollinated species; hence, pollen is likely to be the main mode of gene flow countering selection along local environmental gradients. Implications of these results for silvicultural practices are discussed.

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Close genetic relationship between cultivated and natural populations of common buckwheat in the Sanjiang area is not due to recent gene flow between them—An analysis using microsatellite markers

Genes & Genetic Systems ◽

10.1266/ggs.82.53 ◽

2007 ◽

Vol 82 (1) ◽

pp. 53-64 ◽

Cited By ~ 10

Author(s):

Takehiko Konishi ◽

Ohmi Ohnishi

Keyword(s):

Gene Flow ◽

Microsatellite Markers ◽

Genetic Relationship ◽

Natural Populations ◽

Common Buckwheat ◽

Recent Gene Flow ◽

Close Genetic Relationship

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Phenotypic and phenological behaviours of clones of three natural populations of Atriplex halimus L. grown in a common garden

Ecologia mediterranea ◽

10.3406/ecmed.2003.1551 ◽

2003 ◽

Vol 29 (2) ◽

pp. 179-188

Author(s):

Abdelaziz Abbad ◽

Abdelbasset El Hadrami ◽

Abderrazzak Benchaabane

Keyword(s):

Natural Populations ◽

Common Garden ◽

Atriplex Halimus

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Sex ratio and life history traits at reaching sexual maturity in the dioecious shrub Fuchsia parviflora: field and common garden experiments

Journal of Tropical Ecology ◽

10.1017/s0266467421000043 ◽

2021 ◽

pp. 1-6

Author(s):

Jessica S. Ambriz ◽

Clementina González ◽

Eduardo Cuevas

Keyword(s):

Natural Population ◽

Sexual Maturity ◽

Sex Ratios ◽

Natural Populations ◽

Common Garden ◽

Common Garden Experiment ◽

Trade Offs ◽

Reproductive Biomass ◽

Common Garden Experiments ◽

Growth And Reproduction

Abstract Fuchsia parviflora is a dioecious shrub that depends on biotic pollination for reproduction. Previous studies suggest that the male plants produce more flowers, and male-biased sex ratios have been found in some natural populations. To assess whether the biased sex ratios found between genders in natural populations are present at the point at which plants reach sexual maturity, and to identify possible trade-offs between growth and reproduction, we performed a common garden experiment. Finally, to complement the information of the common garden experiment, we estimated the reproductive biomass allocation between genders in one natural population. Sex ratios at reaching sexual maturity in F. parviflora did not differ from 0.5, except in one population, which was the smallest seedling population. We found no differences between genders in terms of the probability of germination or flowering. When flowering began, female plants were taller than males and the tallest plants of both genders required more time to reach sexual maturity. Males produced significantly more flowers than females, and the number of flowers increased with plant height in both genders. Finally, in the natural population studied, the investment in reproductive biomass was seven-fold greater in female plants than in male plants. Our results showed no evidence of possible trade-offs between growth and reproduction. Despite the fact that female plants invest more in reproductive biomass, they were taller than the males after flowering, possibly at the expense of herbivory defence.

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Long distance pollen-mediated gene flow at a landscape level: the weed beet as a case study

Molecular Ecology ◽

10.1111/j.1365-294x.2007.03448.x ◽

2007 ◽

Vol 16 (18) ◽

pp. 3801-3813 ◽

Cited By ~ 51

Author(s):

STÉPHANE FÉNART ◽

FRÉDÉRIC AUSTERLITZ ◽

JOËL CUGUEN ◽

JEAN-FRANÇOIS ARNAUD

Keyword(s):

Gene Flow ◽

Long Distance ◽

Landscape Level

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87:6432 Gene flow and the geographic structure of natural populations

Deep Sea Research Part B Oceanographic Literature Review ◽

10.1016/0198-0254(87)90895-8 ◽

1987 ◽

Vol 34 (11) ◽

pp. 981

Keyword(s):

Gene Flow ◽

Natural Populations ◽

Geographic Structure

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Spatial genetic substructure within natural populations of jack pine (Pinus banksiana)

Canadian Journal of Botany ◽

10.1139/b91-074 ◽

1991 ◽

Vol 69 (3) ◽

pp. 547-551 ◽

Cited By ~ 36

Author(s):

Chang Yi Xie ◽

Peggy Knowles

Keyword(s):

Spatial Autocorrelation ◽

Pinus Banksiana ◽

Pollen Dispersal ◽

Natural Populations ◽

Jack Pine ◽

Spatial Autocorrelation Analysis ◽

Autocorrelation Analysis ◽

Long Distance ◽

Genetic Substructure ◽

Good Agreement

Spatial autocorrelation analysis was used to investigate the geographic distribution of allozyme genotypes within three natural populations of jack pine (Pinus banksiana Lamb.). Results indicate that genetic substructuring within these populations is very weak and the extent differs among populations. These results are in good agreement with those inferred from mating-system studies. Factors such as the species' predominantly outbreeding system, high mortality of selfs and inbreds prior to reproduction, long-distance pollen dispersal, and the absence of strong microhabitat selection may be responsible for the observed weak genetic substructuring. Key words: jack pine, Pinus banksiana, genetic substructure, allozyme, spatial autocorrelation analysis.

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