Genetic structure of a natural oak community in central Italy: Evidence of gene flow between three sympatric white oak species (Quercus, Fagaceae)


  • Gaby Antonecchia Università degli Studi del Molise, Cda Fonte Lappone IT-86070 Pesche, Italia
  • Paola Fortini Università degli Studi del Molise, Cda Fonte Lappone IT-86070 Pesche, Italia
  • Olivier Lepais INRA, UMR 1224 ECOBIOP, F-64310 Saint Pée sur Nivelle, France, Université Pau and Pays Adour, UMR 1224 ECOBIOP, F-64600 Anglet, France
  • Sophie Gerber INRA, UMR 1202 BIOGECO, 69 route d’Arcachon, F-33612 Cestas cedex, France, Université de Bordeaux, F-33612 Cestas cedex, France
  • Patrick Legér INRA, UMR 1202 BIOGECO, 69 route d’Arcachon, F-33612 Cestas cedex, France
  • Gabriella Stefania Scippa Università degli Studi del Molise, Cda Fonte Lappone IT-86070 Pesche, Italia
  • Vincenzo Viscosi MIUR, Department for Instruction, Institute “O. D’Uva”, IT-86090 Castelpetroso, Italy



bayesian clustering analysis, interspecific gene flow, Italian Peninsula, hybridization, Quercus frainetto, Q. petraea, Q. pubescens, ESTSSRs


Incomplete reproductive barriers between species, especially in sympatric areas where several species coexist, may result in hybridization and an increase in genetic diversity. Here we assessed the amount of genetic diversity in a community of three interfertile and sympatric European oaks (Quercus frainetto Ten., Q. petraea Liebl. Matt. and Q. pubescens Willd.) situated in central Italy. We used 11 microsatellite markers derived from Expressed Sequence Tag (EST-SSRs) and we implemented a Bayesian clustering analysis to assign individuals to species or hybrids. All genotyped loci were polymorphic for all the species and three genetic clusters corresponding to each species were detected. Significant differences and a higher level of gene flow were observed between the three oak species. Occurrence of hybrids varied markedly within the studied area: hybrids between Q. petraea and Q, pubescens were the most frequent, while hybrids between Q. petraea and Q. frainetto were particularly rare. Q. pubescens and Q. petraea showed the highest number of alleles compared to Q. frainetto,which was characterized by a low number of private, but highly frequent, alleles. However, Q. frainetto showed a lower genetic diversity and a stronger reproductive isolation from the other two oak species.


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Research article