Transfer of resistance to the beet cyst nematode (Heterodera schachtii Schm.) into the Brassica napus L. gene pool through intergeneric somatic hybridization with Raphanus sativus L.

An intergeneric somatic hybrid was obtained through PEG-induced protoplast fusion between Brassica napus L. (oil-seed rape, AACC, 2n=38) and a beet cyst nematode resistant genotype of Raphanus sativus L. (fodder radish, RR, 2n=18). The hybrid nature of the regenerated plant was confirmed by flow cytometric analysis, RFLP-analysis, and chromosome counts. Southern blot analysis of total DNA using pPhcPS1 (rbc-L) as probe indicated that the somatic hybrid contains chloroplasts of B. napus. The mitochondrial genome of the somatic hybrid was studied more extensively using several probes and restriction enzymes. The results indicate inter- or intraspecific mitochondrial DNA recombination. Resistance to the beet cyst nematode (Heterodera schachtii Schm., BCN) was expressed in the hybrid at a high level.