RFLP ANALYSIS OF ASYMMETRIC SOMATIC HYBRIDS BETWEEN SOLANUM-TUBEROSUMAND IRRADIATED SOLANUM-BREVIDENS

The nuclear genome composition of five asymmetric somatic hybrids, obt ained by fusion of leaf protoplasts from Solanum tuberosum and gamma-i rradiated leaf protoplasts from S. brevidens, have been analyzed at th e molecular level. An analysis of 21 loci using linkage group-specific restriction fragment length polymorphism (RFLP) was included in the s tudy. All five hybrids contained a complete set of the loci studied fr om S. tuberosum. The degree of elimination of alleles from the irradia ted S. brevidens donor genome ranged from 10-65% in the five asymmetri c hybrids analyzed. The detection of incomplete chromosomes, as well a s non-parental bands in Southern hybridizations with RFLP markers, rev ealed extensive chromosome rearrangements in the asymmetric hybrids.