PRESENT STATE AND PROSPECTS OF BREEDING RAPESEED (BRASSICA-NAPUS) WITH A MAXIMUM ERUCIC-ACID CONTENT FOR INDUSTRIAL APPLICATIONS

Rapeseed oil with proportions of erucic acid (C22:1) substantially higher than the level found in traditional cultivars (ca. 50 % C22:1) are sought by breeders and chemists for use in wellknown industrial processes and products. In a first step available rapeseed and Brassica germplasm was screened for high erucic acid content. Following conventional breeding procedures (e.g. pedigree selection) promising rapeseed genotypes were crossed and the progeny were selected due to genetic variation of oil content and quality. Since rapeseed (B. napus L.) is amenable to improvement through biotechnology as well, further breeding progress was achieved by application of cell and tissue culture techniques, e.g., microspore culture for the production of doubled-haploid lines. Furthermore, an impressive strategy to increase genetic variation is the resynthesis of rapeseed, i.e., by crossing the original ancestors, B. rapa and B. oleracea, accomplished by embryo rescue technique circumventing existing incompatibility barriers. Following this way we have carried out crosses between B. rapa ssp. trilocularis ('Yellow sarson') and several selected cauliflowers in order to create new oilseed rape germplasm with high erucic acid content. The offspring display desirable variation in the content of major fatty acids. Through introgression of resynthesized germplasm into conventional high-erucic acid rapeseed material it should be possible to produce recombinant breeding lines with an erucic acid content of 60 % or even more.