A major QTL on chromosome C05 significantly reduces acid detergent lignin (ADL) content and increases seed oil and protein content in oilseed rape (Brassica napus L.)

Abstract

A reduction in acid detergent lignin content in oilseed rape resulted in an increase in seed oil and protein content. Worldwide increasing demand for vegetable oil and protein requires continuous breeding efforts to enhance the yield of oil and protein crop species. The oil-extracted meal of oilseed rape is currently mainly used for feeding livestock, but efforts are undertaken to use the oilseed rape protein in food production. One limiting factor is the high lignin content of black-seeded oilseed rape that negatively affects digestibility and sensory quality of food products compared to soybean. Breeding attempts to develop yellow seeded oilseed rape with reduced lignin content have not yet resulted in competitive cultivars. The objective of this work was to investigate the inheritance of seed quality in a DH population derived from the cross of the high oil lines SGDH14 and cv. Express. The DH population of 139 lines was tested in field experiments in 14 environments in north-west Europe. Seeds harvested from open pollinated plants were used for extensive seed quality analysis. A molecular marker map based on the Illumina Infinium 60 K Brassica SNP chip was used to map QTL. Amongst others, one major QTL for acid detergent lignin content, explaining 81% of the phenotypic variance, was identified on chromosome C05. Lines with reduced lignin content nevertheless did not show a yellowish appearance, but showed a reduced seed hull content. The position of the QTL co-located with QTL for oil and protein content of the defatted meal with opposite additive effects, suggesting that the reduction in lignin content resulted in an increase in oil and protein content.

Chromosome-Scale Assembly of Winter Oilseed Rape Brassica napus

“…Genetic maps were constructed using the software MSTMap (Wu et al, 2008) applying the Kosambi map function. The genetic linkage map for Express 617 × SGDH14 was produced using 60K Illumina Infinium Brassica SNP array marker data obtained from 139 lines using the software package JoinMap 4.1 (Stam, 1993;van Ooijen, 2011) applying the Kosambi map function (Behnke et al, 2018).…”

Inheritance of seed quality and seed germination in two doubled haploid populations of oilseed rape segregating for acid detergent lignin (ADL) content

“…The plant material can be used in crosses with already identified other lignin mutant genotypes (e.g. Behnke et al 2018) that carry mutations on different chromosomes of the rapeseed A-or C-genome to identify additive and epistatic effects on lignin content and seed color. Despite many attempts to develop yellow seeded rapeseed, black seeded cultivars are still dominating the market.…”

“…However, despite intensive breeding efforts and reported higher seed oil and protein contents of yellow seeded oilseed rape, it has not yet been possible to establish competitive yellow seeded oilseed rape cultivars in the market. Correlations of ADL content to seed coat phenolic compounds suggest that low ADL content is associated with reduced seed coat thickness (Wittkop et al 2012;Behnke et al 2018). Multiple genes and loci have been reported to be involved in the inheritance of seed coat color and testa thickness not only in Arabidopsis thaliana but also in Brassica species (e.g.…”

“…In different populations a large number of QTL on linkage groups A05, A06, A09, C05, C08, C09, for reduced lignin content and yellow seed color have been published (Badani et al 2006;Stein et al 2013;Wang et al 2015Wang et al , 2017Behnke et al 2018;Miao et al 2019). Despite the identification of numerous loci affecting seed coat color in the allopolyploid genome of oilseed rape, none of the identified QTL have led to the development of competitive true yellow seeded rapeseed cultivars.…”

Breeding Canola (Brassica napus L.) for Protein in Feed and Food

“…Quantitative trait loci (QTL) are regions within the genome whose occurrences are associated with specific quantitative phenotypes; multiple QTL each contribute some variation to the phenotype, and multiple genes may reside within each locus [ 144 ]. The successful identification of QTL associated with important seed quality traits in canola such as oil content [ 145 , 146 , 147 , 148 , 149 ], fatty acid composition [ 150 , 151 ], and glucosinolate levels [ 146 , 152 , 153 , 154 , 155 ] have been reported by numerous groups. In contrast, comparatively few reports have focused on the identification of QTL associated with total seed protein in canola [ 145 , 148 , 149 , 155 ].…”