Origin, distribution and mapping of RAPD markers from wildPetunia species inPetunia hybrida Hort lines

We have established the first linkage map forPetunia hybrida based upon both RAPD and phenotypical markers. The progeny studied consisted of 100 BC1 individuals derived from the [(St40xTlvl)xTlvl] back-cross. Each morphological marker has previously been mapped onto one of the seven chromosomes. The map consists of 35 RAPD loci of which 24 were affected onto chromosomes while 10 loci were not affected. The loci covered 262.9 cM with a mean distance of 8.2 cM. They are dispersed over seven linkage groups, of which six are carried on identified chromosomes. The RAPD markers were also applied on a set of tenP. hybrida, lines chosen for their diversity and on a set of seven wild species corresponding to the possible ancestors of theP. hybrida species. The markers were found both in the wild species as well as inP. hybrida lines indicating that they are inherited and are stable enough to establish similarities and to suggest relationships between species. Eight out of the ten lines carry different linkage groups of RAPD markers, which suggest that recombinant events occurred between chromosomes which originated in the wild species.