DETECTION OF GENOMIC REGIONS DIFFERENTIATING 2 CLOSELY-RELATED OAK SPECIES QUERCUS-PETRAEA (MATT) LIEBL AND QUERCUS-ROBUR L

Genomic regions differentiating Quercus petraea and Quercus robur were detected by screening 2800 PCR amplification products using random pr imers on 22 trees of each species sampled in 11 natural populations. O nly two per cent of the amplified fragments exhibited significant freq uency differences between the two species and none of them was specifi c to a species. The nucleotide divergence between the two species esti mated with RAPD data was 0.5 per cent in the overall genome and increa sed to 3.3 per cent in the discriminant regions. Twenty-three informat ive fragments were cloned and partially sequenced. New primers were de rived from these sequences to obtain Sequence Characterized Amplified Region (SCAR) fragments. Southern blot experiments indicated that the SCARs were generally in low copy number in the genome. A search for si milarity between SCAR sequences and sequences contained in data banks revealed that three of them corresponded to known DNA sequences.