Analysis of the introgression of Solanum bulbocastanum DNA into potato breeding lines

Somatic hybrids have been obtained between potato and Solanum bulbocastanum PI 245310, a Mexican diploid (2n=2x=24) species. Through restriction fragm ent length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD ) analyses it was found that the somatic hybrids contain each chromosome of the diploid parent and that the synteny of RFLP markers noted with tomato, potato and S. brevidens is largely maintained in S. bulbocastanum. RFLP an alyses of BC I progeny of two different hybrids indicated that a substantia l number of markers were either lost or were heterozygous, in marked contra st with results previously noted with S. brevidens. A RAPD map for all 12 c hromosomes of S. bulbocastanum was prepared and marker transmission was fol lowed in three BC2 populations. Results with chromosomes 3, 8 and 10 from t hese populations are compared.