DNA analysis of potato plus Solanum brevidens somatic hybrid lines

Three somatic hybrid lines between potato (cv. While Lady line no. Ke 64, 2 n = 2x = 48) + Solanum brevidens (PI 218228, 2n = 2x = 24) were evaluated u sing randomly amplified polymorphic DNA (RAPD) markers. The lines originate d from the same callus but showed different reactions to Erwinia carotovora ssp. carotovora, the cause of potato soft rot. By the use of 48 oligomer p rimers producing 99 scorable bands, DNA polymorphism were detected on 7 of 12 S. brevidens chromosomes. Loss of certain DNA segments on chromosome 5, 6, 9 and 11 were observed. Some of the variations could have taken place in early callus stage of development; others may have occurred after initiati on of individual shoot regeneration. The possible involvement of missing RA PD products specific to one somatic hybrid that shows decreased resistance to bacterial soft rot is discussed.