Inheritance of cellulose, hemicellulose and lignin content in relation to seed oil and protein content in oilseed rape

Abstract

Oilseed rape is worldwide an important oil and protein crop. Its oil is valued because of its excellent quality. The oil extracted meal is marketed as a lower value by-product for feeding livestock. Recently, interest in vegetable proteins has increased to use the oilseed rape protein as an alternative vegetable source for human consumption. However, the use of the protein rich meal for food production is greatly limited by the presence of residual glucosinolate, phenolic acid esters and crude fibre contents which affect its techno-functional properties, taste and colour. Further reducing contents of glucosinolates, cellulose, hemicellulose and indigestible lignin, is expected to enhance protein content and quality. To this end, two half-sib DH populations were tested in replicated field experiments. Inheritance of individual seed fibre components in relation to each other and to oil, protein and glucosinolate content were investigated. The DH populations were genotyped with Brassica 15K SNP Illumina chip, QTL were mapped and candidate genes were identified using the high quality long read reference genome of Express 617. Novel QTL for fibre components were identified that co-located to each other, with QTL for oil, protein and glucosinolate content, and with opposite direction of additive effects. The parallel investigation of two half-sib DH populations gave insight into the direction of the additive effects which depended on the indvidual parents. The results provide additional understanding of genetic loci underlying the seed quality traits which may help achieving the breeding goals in oilseed rape.

A systems genomics and genetics approach to identify the genetic regulatory network for lignin content in Brassica napus seeds

“…QTLs for NDF, ADF, and ADL colocalized at the same genetic locus, indicating these three components of lignin shared the same genetic architecture. Numerous QTLs for seed quality traits including seed colour, oil, protein, and fibre were previously identified on the A09 chromosome ( Wittkop et al., 2009 ; Liu et al., 2012 , 2013 ; Yu et al., 2016 ; Behnke et al., 2018 ; Miao et al., 2019 ; Chao et al., 2022 ; Yusuf and Möllers, 2024 ), indicating that A09 is a hotspot that harbours several genes for these seed quality traits. However, this study and all previous research have used a relatively small population size, from ~100 to 300 lines, making it challenging to precisely identify QTLs within this hotspot.…”

“…Fibre in seed meal negatively affects digestion and processibility for animal feed, and reducing the seed fibre content in oilseed rape could result in increased seed oil and protein content ( Wittkop et al., 2009 ; Snowdon et al., 2010 ; Liu et al., 2012 , 2013 ; Yu et al., 2016 ; Behnke et al., 2018 ; Miao et al., 2019 ; Chao et al., 2022 ; Yusuf and Möllers, 2024 ). Therefore, the low fibre trait was identified as a high-value target for canola ( Brassica napus ) breeding programs.…”