@article {162, title = {Multiple nuclear genes stabilize the phylogenetic backbone of the genus Quercus}, journal = {Systematics and BiodiversitySystematics and Biodiversity}, year = {2014}, pages = {1-19}, publisher = {Taylor \& Francis}, abstract = {Phylogenetic relationships among 108 oak species (genus Quercus L.) were inferred using DNA sequences of six nuclear genes selected from the existing genomic resources of the genus. Previous phylogenetic reconstructions based on traditional molecular markers are inconclusive at the deeper nodes. Overall, weak phylogenetic signals were obtained for each individual gene analysis, but stronger signals were obtained when gene sequences were concatenated. Our data support the recognition of six major intrageneric groups Cyclobalanopsis, Cerris, Ilex, Quercus, Lobatae and Protobalanus. Our analyses provide resolution at deeper nodes but with moderate support and a more robust infrageneric classification within the two major clades, the ?Old World Oaks? (Cyclobalanopsis, Cerris, Ilex) and ?New World Oaks? (Quercus, Lobatae, Protobalanus). However, depending on outgroup choice, our analysis yielded two alternative placements of the Cyclobalanopsis clade within the genus Quercus. When Castanea Mill. was chosen as outgroup, our data suggested that the genus Quercus comprised two clades corresponding to two subgenera as traditionally recognized by Camus: subgenus Euquercus Hickel and Camus and subgenus Cyclobalanopsis ?ersted (Schneider). However, when Notholithocarpus Manos, Cannon and S. Oh was chosen as an outgroup subgenus Cyclobalanopsis clustered with Cerris and Ilex groups to form the Old World clade. To assess the placement of the root, we complemented our dataset with published data of ITS and CRC sequences. Based on the concatenated eight gene sequences, the most likely root position is at the split between the ?Old World Oaks? and the ?New World Oaks?, which is one of the alternative positions suggested by our six gene analysis. Using a dating approach, we inferred an Eocene age for the primary divergences in Quercus and a root age of about 50?55 Ma, which agrees with palaeobotanical evidence. Finally, irrespective of the outgroup choice, our data boost the topology within the New World clade, where (Protobalanus + Quercus) is a sister clade of Lobatae. Inferred divergence ages within this clade and the Cerris?Ilex clade are generally younger than could be expected from the fossil record, indicating that morphological differentiation pre-dates genetic isolation in this clade.}, isbn = {1477-2000}, author = {Hubert, Fran{\c c}ois and Grimm, Guido W. and Jousselin, Emmanuelle and Berry, Vincent and Franc, Alain and Kremer, Antoine} } @article {160, title = {High Rates of Gene Flow by Pollen and Seed in Oak Populations across Europe}, journal = {PLoS ONEPLoS ONE}, volume = {9}, number = {1}, year = {2014}, pages = {e85130}, publisher = {Public Library of Science}, abstract = {

Gene flow is a key factor in the evolution of species, influencing effective population size, hybridisation and local adaptation. We analysed local gene flow in eight stands of white oak (mostly Quercus petraea and Q. robur, but also Q. pubescens and Q. faginea) distributed across Europe.

Adult trees within a given area in each stand were exhaustively sampled (range [239, 754], mean 423), mapped, and acorns were collected ([17,147], 51) from several mother trees ([3], [47], 23). Seedlings ([65,387], 178) were harvested and geo-referenced in six of the eight stands. Genetic information was obtained from screening distinct molecular markers spread across the genome, genotyping each tree, acorn or seedling. All samples were thus genotyped at 5{\textendash}8 nuclear microsatellite loci. Fathers/parents were assigned to acorns and seedlings using likelihood methods. Mating success of male and female parents, pollen and seed dispersal curves, and also hybridisation rates were estimated in each stand and compared on a continental scale.

On average, the percentage of the wind-borne pollen from outside the stand was 60\%, with large variation among stands (21{\textendash}88\%). Mean seed immigration into the stand was 40\%, a high value for oaks that are generally considered to have limited seed dispersal. However, this estimate varied greatly among stands (20{\textendash}66\%). Gene flow was mostly intraspecific, with large variation, as some trees and stands showed particularly high rates of hybridisation.

Our results show that mating success was unevenly distributed among trees. The high levels of gene flow suggest that geographically remote oak stands are unlikely to be genetically isolated, questioning the static definition of gene reserves and seed stands.

}, author = {Gerber, Sophie and Chad{\oe}uf, Jo{\"e}l and Gugerli, Felix and Lascoux, Martin and Buiteveld, Joukje and Cottrell, Joan and Dounavi, Aikaterini and Fineschi, Silvia and Forrest, Laura L. and Fogelqvist, Johan and Goicoechea, Pablo G. and Jensen, Jan Svejgaard and Salvini, Daniela and Vendramin, Giovanni G. and Kremer, Antoine} }