02459nas a2200289   4500008004100000020001400041245006600055210006600121300001200187490000700199520162900206653002901835653002401864653002301888653002301911653001701934653002001951653001801971653003501989100001702024700002302041700001602064700001302080700001402093700001802107856004402125       2013                        eng d  a1365-294X00aOutlier loci highlight the direction of introgression in oaks0 aOutlier loci highlight the direction of introgression in oaks  a450-4620 v223 aLoci considered to be under selection are generally avoided in attempts to infer past demographic processes as they do not fit neutral model assumptions. However, opportunities to better reconstruct some aspects of past demography might thus be missed. Here we examined genetic differentiation between two sympatric European oak species with contrasting ecological dynamics (Quercus robur and Quercus petraea) with both outlier (i.e. loci possibly affected by divergent selection between species or by hitchhiking effects with genomic regions under selection) and nonoutlier loci. We sampled 855 individuals in six mixed forests in France and genotyped them with a set of 262 SNPs enriched with markers showing high interspecific differentiation, resulting in accurate species delimitation. We identified between 13 and 74 interspecific outlier loci, depending on the coalescent simulation models and parameters used. Greater genetic diversity was predicted in Q. petraea (a late-successional species) than in Q. robur (an early successional species) as introgression should theoretically occur predominantly from the resident species to the invading species. Remarkably, this prediction was verified with outlier loci but not with nonoutlier loci. We suggest that the lower effective interspecific gene flow at loci showing high interspecific divergence has better preserved the signal of past asymmetric introgression towards Q. petraea caused by the species' contrasting dynamics. Using markers under selection to reconstruct past demographic processes could therefore have broader potential than generally recognized.10aasymmetric introgression10adivergent selection10agene flow barriers10agenetic assignment10aoutlier loci10aQuercus petraea10aQuercus robur10asingle nucleotide polymorphism1 aGuichoux, E.1 aGarnier-GÉRÉ, P.1 aLagache, L.1 aLang, T.1 aBoury, C.1 aPetit, R., J.  uhttps://quercus.myspecies.info/node/15402151nas a2200241   4500008004100000020001400041245006200055210006100117300001200178520145400190653001601644653001601660653002201676653002301698653002201721653002001743653001801763100002001781700002301801700002001824700002101844856004401865       2012                        eng d  a1365-294X00aFine-scale environmental control of hybridization in oaks0 aFinescale environmental control of hybridization in oaks  an/a-n/a3 aNatural hybridization is attracting much interest in modern speciation and conservation biology studies, but the underlying mechanisms remain poorly understood. In particular, it is unclear why environmental changes often increase hybridization rates. To study this question, we surveyed mating events in a mixed oak stand and developed a spatially explicit individual-based hybridization model. This model, where hybridization is frequency-dependent, pollen is nonlimiting and which allows immigrant pollen to compete with local pollen, takes into account species-specific pollen dispersal and sexual barriers to hybridization. The consequences of pollen limitation on hybridization were studied using another simple model. The results indicate that environmental changes could increase hybridization rates through two distinct mechanisms. First, by disrupting the spatial organization of communities, they should decrease the proportion of conspecific pollen available for mating, thus increasing hybridization rates. Second, by decreasing the density of conspecifics, they should increase pollen limitation and thus hybridization rates, as a consequence of chance pollination predominating over deterministic pollen competition. Altogether, our results point to a need for considering hybridization events at the appropriate level of organization and provide new insights into why hybridization rates generally increase in disturbed environments.10adisturbance10aimmigration10amass action model10apaternity analysis10apollen limitation10aQuercus petraea10aQuercus robur1 aLagache, Lélia1 aKlein, Etienne, K.1 aGuichoux, Erwan1 aPetit, Rémy, J.  uhttps://quercus.myspecies.info/node/14702636nas a2200217   4500008004100000020001400041245010500055210006900160260002900229300001000258520193300268653001802201653001802219653001602237653003302253100002402286700002502310700001702335700002202352856004402374       2012                        eng d  a1365-294X00aMitochondrial barcodes are diagnostic of shared refugia but not species in hybridizing oak gallwasps0 aMitochondrial barcodes are diagnostic of shared refugia but not   bBlackwell Publishing Ltd  ano-no3 aMitochondrial DNA barcodes provide a simple taxonomic tool for systematic and ecological research, with particular benefit for poorly studied or species-rich taxa. Barcoding assumes genetic diversity follows species boundaries; however, many processes disrupt species-level monophyly of barcodes leading to incorrect classifications. Spatial population structure, particularly when shared across closely related and potentially hybridizing taxa, can invalidate barcoding approaches yet few data exist to examine its impacts. We test how shared population structure across hybridizing species impacts upon mitochondrial barcodes by sequencing the cytochrome b gene for 518 individuals of four well-delimited Western Palaearctic gallwasp species within the Andricus quercuscalicis species group. Mitochondrial barcodes clustered individuals into mixed-species clades corresponding to refugia, with no difference in within- and between-species divergence. Four nuclear genes were also sequenced from 4 to 11 individuals per refugial population of each species. Multi-locus analyses of these data supported established species, with no support for the refugial clustering across species seen in mitochondrial barcodes. This pattern is consistent with mitochondrial introgression among populations of species sharing the same glacial refugium, such that mitochondrial barcodes identify a shared history of population structure rather than species. Many taxa show phylogeographic structure across glacial refugia, suggesting that mitochondrial barcoding may fail when applied to other sets of co-distributed, closely related species. Robust barcoding approaches must sample extensively across population structure to disentangle spatial from species-level variation. Methods incorporating multiple unlinked loci are also essential to accommodate coalescent variation among genes and provide power to resolve recently diverged species.10aDNA barcoding10aintrogression10amulti-locus10aspatial population structure1 aNicholls, James, A.1 aChallis, Richard, J.1 aMutun, Serap1 aStone, Graham, N.  uhttps://quercus.myspecies.info/node/14902379nas a2200145   4500008004100000020001400041245015900055210006900214300001400283490000700297520184800304100002102152700001602173856004402189       2010                        eng d  a1365-294X00aRealized gene flow within mixed stands of <i>Quercus robur </i>L. and <i>Q. petraea</i> (Matt.) L. revealed at the stage of naturally established seedling0 aRealized gene flow within mixed stands of iQuercus robur iL and   a2137-21510 v193 aThe estimates of contemporary gene flow assessed based on naturally established seedlings provide information much needed for understanding the abilities of forest tree populations to persist under global changes through migration and/or adaptation facilitated by gene exchange among populations. Here, we investigated pollen- and seed-mediated gene flow in two mixed-oak forest stands (consisting of Quercus robur L. and Q. petraea [Matt.] Liebl.). The gene flow parameters were estimated based on microsatellite multilocus genotypes of seedlings and adults and their spatial locations within the sample plots using models that attempt to reconstruct the genealogy of the seedling cohorts. Pollen and seed dispersal were modelled using the standard seedling neighbourhood model and a modification2014the 2-component seedling neighbourhood model, with the later allowing separation of the dispersal process into local and long-distance components. The 2-component model fitted the data substantially better than the standard model and provided estimates of mean seed and pollen dispersal distances accounting for long-distance propagule dispersal. The mean distance of effective pollen dispersal was found to be 298 and 463 m, depending on the stand, while the mean distance of effective seed dispersal was only 8.8 and 15.6 m, which is consistent with wind pollination and primarily seed dispersal by gravity in Quercus. Some differences observed between the two stands could be attributed to the differences in the stand structure of the adult populations and the existing understory vegetation. Such a mixture of relatively limited seed dispersal with occasional long distance gene flow seems to be an efficient strategy for colonizing new habitats with subsequent local adaptation, while maintaining genetic diversity within populations.1 aChybicki, I., J.1 aBurczyk, J.  uhttps://quercus.myspecies.info/node/12202787nas a2200277   4500008004100000020001400041245015100055210006900206260002900275300001400304490000700318520186300325653004302188653001902231653002102250653002802271653002302299100002302322700002102345700002102366700001602387700002202403700001902425700002102444856004402465       2010                        eng d  a1365-294X00aGene movement and genetic association with regional climate gradients in California valley oak (Quercus lobata Née) in the face of climate change0 aGene movement and genetic association with regional climate grad  bBlackwell Publishing Ltd  a3806-38230 v193 aAbstract Rapid climate change jeopardizes tree populations by shifting current climate zones. To avoid extinction, tree populations must tolerate, adapt, or migrate. Here we investigate geographic patterns of genetic variation in valley oak, Quercus lobata Née, to assess how underlying genetic structure of populations might influence this species’ ability to survive climate change. First, to understand how genetic lineages shape spatial genetic patterns, we examine historical patterns of colonization. Second, we examine the correlation between multivariate nuclear genetic variation and climatic variation. Third, to illustrate how geographic genetic variation could interact with regional patterns of 21st Century climate change, we produce region-specific bioclimatic distributions of valley oak using Maximum Entropy (MAXENT) models based on downscaled historical (1971–2000) and future (2070–2100) climate grids. Future climatologies are based on a moderate-high (A2) carbon emission scenario and two different global climate models. Chloroplast markers indicate historical range-wide connectivity via colonization, especially in the north. Multivariate nuclear genotypes show a strong association with climate variation that provides opportunity for local adaptation to the conditions within their climatic envelope. Comparison of regional current and projected patterns of climate suitability indicates that valley oaks grow in distinctly different climate conditions in different parts of their range. Our models predict widely different regional outcomes from local displacement of a few kilometres to hundreds of kilometres. We conclude that the relative importance of migration, adaptation, and tolerance are likely to vary widely for populations among regions, and that late 21st Century conditions could lead to regional extinctions.10achloroplast and nuclear microsatellite10aclimate change10aclimate envelope10aenvironmental gradients10alandscape genetics1 aSork, Victoria, L.1 aDavis, Frank, W.1 aWestfall, Robert1 aFlint, Alan1 aIkegami, Makihiko1 aWang, Hongfang1 aGrivet, Delphine  uhttps://quercus.myspecies.info/node/129