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/14702222nas a2200301   4500008004100000020001400041245017800055210006900233260002900302300001000331520122500341653002301566653002601589653003301615653002401648653002001672653001801692653002701710100001501737700001601752700001801768700001501786700001801801700001901819700001501838700002301853856004401876       2011                        eng d  a1420-910100aStrength, diversity and plasticity of postmating reproductive barriers between two hybridizing oak species (<i>Quercus robur </i>L. and <i>Quercus petraea </i>(Matt) Liebl.)0 aStrength diversity and plasticity of postmating reproductive bar  bBlackwell Publishing Ltd  ano-no3 aVery little is known about the nature and strength of reproductive isolation (RI) in Quercus species, despite extensive research on the estimation and evolutionary significance of hybridization rates. We characterized postmating pre- and postzygotic RI between two hybridizing oak species, Quercus robur and Quercus petraea, using a large set of controlled crosses between different genotypes. Various traits potentially associated with reproductive barriers were quantified at several life history stages, from pollen–pistil interactions to seed set and progeny fitness-related traits. Results indicate strong intrinsic postmating prezygotic barriers, with significant barriers also at the postzygotic level, but relatively weaker extrinsic barriers on early hybrid fitness measures assessed in controlled conditions. Using general linear modelling of common garden data with clonal replicates, we showed that most traits exhibited important genotypic differences, as well as different levels of sensitivity to micro-environmental heterogeneity. These new findings suggest a large potential genetic diversity and plasticity of reproductive barriers and are confronted with hybridization evidence in these oak species.10acontrolled crosses10aecological speciation10apollen–pistil interactions10aprezygotic barriers10aQuercus petraea10aQuercus robur10areproductive isolation1 aAbadie, P.1 aRoussel, G.1 aDencausse, B.1 aBonnet, C.1 aBertocchi, E.1 aLouvet, J., M.1 aKremer, A.1 aGarnier-GÉRÉ, P.  uhttps://quercus.myspecies.info/node/132