02289nas a2200265   4500008004100000245013400041210006900175300001200244490000700256520147500263653001401738653002801752653001701780653001801797653002001815653001201835100002601847700003001873700001501903700001601918700001301934700002101947700001201968856004301980       2005                        eng d00aGene flow and hybridisation in a mixed oak forest (Quercus pyrenaica Willd. and Quercus petraea (Matts.) Liebl.) in central Spain0 aGene flow and hybridisation in a mixed oak forest Quercus pyrena  a457-4650 v953 aOaks are long-standing models for the study of gene flow and hybridisation. Temperate (Quercus petraea) and sub-Mediterranean (Quercus pyrenaica) oaks coexist in central Spain, showing remarkable differences in population size and structure. Q. petraea has a scattered distribution in central Spain, where it is at one of the southernmost limits of its range, and forms low-density stands; in contrast, Q. pyrenaica is widespread in the region. We selected a mixed population of the two species (approx13 ha, 176 adults and 96 saplings) to compare the patterns of gene flow within each species and the extent of introgression between them. Using five nuclear microsatellite markers, we performed a parentage analysis and found considerable immigration from outside the stand (approx38% for Q. petraea and approx34% for Q. pyrenaica), and estimated average seed-dispersal distances of 42 and 14 m for Q. petraea and Q. pyrenaica, respectively. Introgression between species was also estimated using our microsatellite battery. First, we developed a multivariate discriminant approach and, second, we compared our results with a widely used clustering method (STRUCTURE). Both analyses were consistent with a low level of introgression between Q. petraea and Q. pyrenaica. Indeed, only 15 adult trees, approx8.5%, were identified as putative hybrids when both methods of analysis were combined. Hybrids may be most common in contact zones due merely to physical proximity.10agene flow10agenetic differentiation10ahybrid zones10aintrogression10amicrosatellites10aQuercus1 aValbuena-Carabana, M.1 aGonzalez-Martinez, S., C.1 aSork, V.L.1 aCollada, C.1 aSOTO, A.1 aGoicoechea, P.G.1 aGil, L.  uhttps://quercus.myspecies.info/node/36