Breeding for a reduced fiber content in oilseed rape (Brassica napus L.) - LoFiRaps

The continuous increase in oil and protein content as well as the improvement in protein quality is a constant goal of oilseed rape breeding. Further breeding progress towards increasing oil and protein content in the seeds can only be achieved by reducing the crude fiber content. Crude fiber consists of hemicellulose, cellulose and lignin. From a nutritional point of view, breeding for a reduced content of indigestible lignin is of major importance. A reduction of the lignin content should lead to improved utilization options of oilseed meal and protein in animal and human nutrition. The overall goal of the project is therefore the exploitation of existing genetic variation for reduced crude fiber content in oilseed rape.
Plant material with significant genetic variation for crude fiber will be developed and analyzed according to Van Soest et al. (1991). The laboratory results will be used for a NIRS calibration development for cellulose, hemicellulose and lignin content, to be used in research and commercial breeding programs. The genotypes will be characterized on the molecular level by using the Illumina Infinium Brassica 15K SNP-Chip with the aim to identify relevant regions of the genome, which will allow a targeted combination of material with different QTL. The effects of an already detected major QTL on C05 for reduced ADL (lignin) content on oil, protein and grain yield are determined in field trials. Furthermore, a genotyping-by-sequencing (GBS) approach is pursued to increase of the available SNP marker density in proximity to the major QTL for reduced lignin content on C05. With additional SNP polymorphisms, KASP markers are generated and fine-mapping of the major QTL in segregating F2 populations will be conducted. An additional approach is the knock-out of a potential candidate gene for reduced lignin content using the CRISPR/Cas9 approach with a subsequent genotypic and phenotypic characterization.