FATTY-ACID INHERITANCE IN WIDE RECIPROCAL OILSEED CROSSES (BRASSICA-RAPA AND BRASSICA-NAPUS)

Erucic acid content and inheritance were studied in Brassica alboglabr a, B. rapa and resynthesized B. napus from these parental species. Alt hough significant variation in erucic acid content was found between t he 20 B. alboglabra lines, all of them had to be classified as high er ucic types. No major erucic acid gene polymorphism was identified. In B. rapa the erucic acid content was regulated by one major gene, which showed partial dominance in three of the four crosses analysed. The h igh erucic gene seemed to function more efficiently in the Yellow Sars on cytoplasm, resulting in maternal differences when reciprocal crosse s were compared. In crosses where modern low erucic acid lines were us ed as female parents the zero erucic acid F-2-individuals occurred mor e frequently than expected. Segregation of the erucic acid content in crosses involving resynthesized B. napus showed a good fit to a two lo cus model. No maternal effects were found, but deviations from mid-par ent values in the high erucic acid direction occurred in most of the F -2-hybrids, indicating partial dominance. Crosses between resynthesize d oilseed rape and natural oilseed rape resulted in oleic acid transgr essive F-2-lines.