genetic linkage map of Quercus robur L. (pedunculate oak) based on RAPD, SCAR, microsatellite, minisatellite, isozyme and 5S rDNA markers

A genetic map of Pedunculate oak (Quercus robur) was constructed based on one 5S rDNA, 271 RAPD, ten SCAR, 18 microsatellite, one minisatellite, and six isozyme markers. A total of 94 individuals from a full-sib family was genotyped. Two maps, including 307 markers, were constructed according to the "two-way pseudo-testcross" mapping strategy. Testcross markers segregating in the 1:1 ratio were first used to establish separate maternal (893.2 cM, 12 linkage groups) and paternal (921.7 cM, 12 linkage groups) maps. Both maps provided 85-90% genome coverage. Homologies between the male and female linkage groups were then identified based on 74 intercross markers segregating in the 3:1, 1:2:1 and 1:1:1:1 ratios (RAPDs, SCARs, SSRs, 5S rDNA and isozymes) in the hybrid progeny. In each map, approximately 18% of the studied markers showed segregation distortion. More than 60% of the skewed markers were due to an excess of heterozygote genotypes. This map will be used for: (1) studying the molecular organisation of genomic regions involved in inter- and intraspecific differentiation in oaks and (2) identification of QTLs for adaptive traits.