Comparison of levels of genetic diversity detected with AFLP and microsatellite markers within and among mixed Q. petraea (Matt.) Liebl. and Q. robur L. stands
Comparaison des niveaux de diversité génétique détectés avec des marqueurs AFLP et microsatellites entre et parmi des peuplements mixtes de Quercus petraea et Quercus robur
Résumé
The aim of this study was to compare genetic diversity within and among Quercus spp. populations based on two contrasting types of nuclear markers. Seven mixed stands of Quercus petraea and Quercus robur were analysed using six highly polymorphic and codominantly inherited microsatellite markers as well as 165 dominant AFLP markers. Genetic differentiation and genetic diversity within each population were assessed. The intra- and inter-locus variances were calculated, and the results were used to compare the genetic diversity between populations. Both classes of markers revealed similar results: the genetic diversity within population and the genetic differentiation among populations is greater in Q. petraea than in Q. robur. The genetic differentiation is generally higher when AFLP markers were used in comparison to microsatelli- tes. For AFLPs, the inter-locus variance is always much higher than the intra-locus variance, and explains why it was not possible to distinguish populations using this marker system. Finally, no significant positive correlation was found between the level of within-population diversity assessed with the two markers.