Restriction endonuclease cleavage site map of safflower (Carthamus tinctorius L.) chloroplast DNA

The restriction endonucleases SalI, PstI, KpnI and HindIII have been used to construct a physical map of safflower (Carthamus tinctorius L.) chloroplast DNA. This was accomplished by hybridizing Southern blots of single and double digested chloroplast DNA with (32)P-dCTP nick-translated SalI, KpnI and HindIII probes which were individually isolated from agarose gels. The chloroplast DNA was found to be circular and to contain approximately 151 kbp. In common with many other higher plant chloroplast DNAs a sequence of about 25 kbp is repeated in an inverted orientation. The small and large single copy regions separating the two repeated segments contain about 20 kbp and 81 kbp, respectively. The rRNA structural genes were also mapped by Southern blot hybridization and are co-linear with several other plant species.