Rapeseed as a Domestic Protein Source of Excellent Quality for Human Consumption - RaPEQ Phase2

As an indigenous, GMO-free, sustainable and competitive source of protein, oilseed rape protein (RSP) has a high potential in terms of human nutrition and vegetarian and vegan meat analogues. Nevertheless, factors such as suboptimal protein content, antinutritive compounds and off-flavour components currently still limits its use. Within the framework of the BMBF funded RaPEQ1 interdisciplinary research project, kaempferol 3-o-(2′′′-o-sinapoyl-β-sophoroside) (K3OSS) could be identified as the most important unpleasant tasting compound in RSP (Hald et al. 2018). The aim is to reduce or eliminate the off-taste problem caused mainly by K3OSS in ongoing RaPEQ2. In addition, several genomic regions relevant for seed protein and seed oil content as well as for the main storage proteins cruciferin and napin could be determined in RaPEQ1. It could be shown that protein quality can be increased by altering the cruciferin/napin-ratio, which is a seed trait that shows significant genetic variation in European oilseed rape varieties.
With the purpose of developing lines during RaPEQ2 with a very high cruciferin and protein content at Göttingen, two suitable genotypes found by germplasm screening during RaPEQ1 were crossed to establish a doubled haploid (DH) population for field-testing in Germany. Marker assisted breeding (MAB) tools will be used to identify genetic loci and interactions between bitter taste stimuli, cruciferin and high protein content. Furthermore, low-sinapine double mutant (SGT) plants (Emrani et al. 2015) are used to create a framework for genetic dissection with the aim of comprehensively understand the genetic interactions between bitter taste components as KO3SS and sinapine acid esters. Furthermore, investigating how SGT gene copies in seed material of a segregating, back-crossed F2 field population have an influence on above-mentioned traits, the PCR-based KASP™ genotyping assay for accurate bi-allelic discrimination of known single nucleotide polymorphisms (SNPs) will be carried out in ongoing RaPEQ2 followed by metabolome analysis and NIRS (Near Infared Reflectance Spectrometry) measurements. The aforementioned SGT mutant was additionally used in a cross with a genotype that showed very low kaempferol levels in preliminary tests. The approach of this subproject is to explore the genetic variation for bitter taste stimuli in a biparental population. For this, the progenies of that crossing will be field-tested and analysed using MAB.