Variation in culture,isoenzyme patterns and plastid DNA in the genusDaucus

Summary To identify markers for fusion and transformation studies, cell suspension cultures of four members of theDaucus genus were examined to determine differences in culture conditions, isoenzyme patterns, and plastid DNA. The four were:D. carota subsp.sativus cv. Danvers,D. carota subsp.gummifer, D. capillifolius, andD. pusillus. Under appropriate conditions, all four grew well as liquid cell suspension cultures and regenerated from protoplasts into plants. Enzyme activities of homoserine dehydrogenase (HSDH) and alcohol dehydrogenase from cell culture extracts were analyzed on electrophoretic gels. Although only one form of HSDH was present in eachDaucus line, the rate of migration of HSDH from cv. Danvers was different from that of the other cell lines. Multiple isoenzymic forms of ADH were present in eachDaucus cultivar. Camparison of endonuclease restriction fragment patterns from plastid DNAs digested by BamHI revealed only small differences between plastid DNAs of cv. Danvers and subsp.Gummifer, whereas large differences were observed between cv. Danvers andD. pusillus plastid DNA patterns. No differences were found between cv. Danvers andD. capillifolius plastid DNA patterns when examined using eight different restriction enzymes. The data indicate that specific isoenzyme and organelle DNA restriction fragment patterns will be useful markers for precise identification of genomes of differentDaucus species in somatic hybridization experiments. This research was supported by the U.S. Department of Agriculture under Agreement 59-2246-1-1-737-0.