Molecular breeding of oilseed rape (Brassica napus) with modified oil quality for nutritional and non-food purposes

摘要

The absolute changes of fatty acid contents achieved in this work were small but consistent and heritable; KAS-Fat double-gene constructs proved to be superior to single gene-constructs regarding the formation of MCFA. This is thought to be due to limitations in the storing or channelling process, e.g. the necessity of a specific acyhransferase (PDAT). Modification of further enzymes, e.g. PDAT, is expected to lead to higher MCFA contents. Regarding tocopherol content and composition, the best individual transgenic plants snowed nearly twice Ihe tocopherol content of the controls. The combination of an optimum ratio of C18:2 to C18:3 (approx. 2:1) with a high tocopherol content characterizes a superior rapeseed oil quality for nutritional usages. Overall it can be concluded that genetic engineering is not only a powerful tool to elucidate the genetics of biosynthetic pathways, but also useful for creating new phenotypes. A next step will be the incorporation of these prototypes into oilseed rape breeding programmes in order to create environmentally stable, high-quality genotypes combined with high agronomic value and market potential.